commit 74215a0b1d7f73abbad395ab43ea9758af1b3734
Author: blankie <blankie@nixnetmail.com>
Date:   Wed Nov 22 19:39:24 2023 +1100

    Initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..378eac2
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+build
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..6a59a3d
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "thirdparty/httplib"]
+	path = thirdparty/httplib
+	url = https://github.com/yhirose/cpp-httplib.git
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..42b78c5
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,40 @@
+cmake_minimum_required(VERSION 3.16)
+
+project(coyote C CXX)
+
+
+find_package(nlohmann_json REQUIRED)
+find_package(CURL REQUIRED)
+set(HTTPLIB_REQUIRE_OPENSSL ON)
+add_subdirectory(thirdparty/httplib)
+#find_package(PkgConfig REQUIRED)
+#pkg_check_modules(HIREDIS REQUIRED hiredis)
+
+
+if (CMAKE_BUILD_TYPE MATCHES "Debug")
+    if (NOT FLAGS)
+        list(APPEND FLAGS -fsanitize=undefined,thread)
+    endif()
+    # https://sourceforge.net/p/valgrind/mailman/valgrind-users/thread/Ygze8PzaQAYWlKDj%40wildebeest.org/
+    list(APPEND FLAGS -gdwarf-4)
+endif()
+
+# https://t.me/NightShadowsHangout/670691
+list(APPEND FLAGS -Werror -Wall -Wextra -Wshadow -Wpedantic -Wno-gnu-anonymous-struct -fPIC -fno-rtti -Wconversion -Wno-unused-parameter -Wimplicit-fallthrough)
+
+# i have no idea why this hack wasn't needed before but it's needed if sanitizers are used
+add_link_options(${FLAGS})
+
+
+add_executable(${PROJECT_NAME} main.cpp numberhelper.cpp config.cpp models.cpp client.cpp servehelper.cpp
+    routes/css.cpp routes/user.cpp
+    blankie/serializer.cpp blankie/escape.cpp)
+set_target_properties(${PROJECT_NAME}
+    PROPERTIES
+        CXX_STANDARD 20
+        CXX_STANDARD_REQUIRED YES
+        CXX_EXTENSIONS NO
+)
+target_include_directories(${PROJECT_NAME} PRIVATE thirdparty ${HIREDIS_INCLUDE_DIRS})
+target_link_libraries(${PROJECT_NAME} PRIVATE nlohmann_json::nlohmann_json httplib::httplib CURL::libcurl ${HIREDIS_LINK_LIBRARIES})
+target_compile_options(${PROJECT_NAME} PRIVATE ${FLAGS})
diff --git a/blankie/escape.cpp b/blankie/escape.cpp
new file mode 100644
index 0000000..b30b4c9
--- /dev/null
+++ b/blankie/escape.cpp
@@ -0,0 +1,42 @@
+#include <stdexcept>
+
+#include "escape.h"
+
+static inline const char* get_replacement(char c);
+
+namespace blankie {
+namespace html {
+
+std::string escape(const std::string& in) {
+    std::string out;
+    size_t pos = 0;
+    size_t last_pos = 0;
+
+    out.reserve(in.size());
+    while ((pos = in.find_first_of("&<>\"'", pos)) != std::string::npos) {
+        out.append(in, last_pos, pos - last_pos);
+        out.append(get_replacement(in[pos]));
+        pos++;
+        last_pos = pos;
+    }
+
+    if (in.size() > last_pos) {
+        out.append(in, last_pos);
+    }
+
+    return out;
+}
+
+} // namespace html
+} // namespace blankie
+
+static inline const char* get_replacement(char c) {
+    switch (c) {
+        case '&': return "&amp;";
+        case '<': return "&lt;";
+        case '>': return "&gt;";
+        case '"': return "&quot;";
+        case '\'': return "&#x27;";
+        default: __builtin_unreachable();
+    }
+}
diff --git a/blankie/escape.h b/blankie/escape.h
new file mode 100644
index 0000000..4045588
--- /dev/null
+++ b/blankie/escape.h
@@ -0,0 +1,11 @@
+#pragma once
+
+#include <string>
+
+namespace blankie {
+namespace html {
+
+std::string escape(const std::string& in);
+
+} // namespace html
+} // namespace blankie
diff --git a/blankie/serializer.cpp b/blankie/serializer.cpp
new file mode 100644
index 0000000..5a3d43d
--- /dev/null
+++ b/blankie/serializer.cpp
@@ -0,0 +1,62 @@
+#include <cstring>
+#include <stdexcept>
+
+#include "escape.h"
+#include "serializer.h"
+
+static inline bool is_autoclosing_tag(const char* tag);
+
+namespace blankie {
+namespace html {
+
+std::string Element::serialize() const {
+    std::string out;
+
+    out += '<';
+    out += this->tag;
+    for (const auto &[key, value] : this->attributes) {
+        out += ' ';
+        out += key;
+        if (!value.empty()) {
+            out += "=\"";
+            out += escape(value);
+            out += '"';
+        }
+    }
+    out += '>';
+
+    if (is_autoclosing_tag(this->tag)) {
+        return out;
+    }
+
+    for (const Node& node : this->nodes) {
+        if (const Element* element = std::get_if<Element>(&node)) {
+            out += element->serialize();
+        } else if (const char* const* text = std::get_if<const char*>(&node)) {
+            out += escape(*text);
+        } else if (const std::string* str = std::get_if<std::string>(&node)) {
+            out += escape(*str);
+        } else if (const HTMLString* html_str = std::get_if<HTMLString>(&node)) {
+            out += html_str->str;
+        } else {
+            throw std::runtime_error("Encountered unknown node");
+        }
+    }
+
+    out += "</";
+    out += this->tag;
+    out += '>';
+
+    return out;
+}
+
+} // namespace html
+} // namespace blankie
+
+static inline bool is_autoclosing_tag(const char* tag) {
+    return !strncmp(tag, "link", 5)
+        || !strncmp(tag, "meta", 5)
+        || !strncmp(tag, "img", 4)
+        || !strncmp(tag, "br", 3)
+        || !strncmp(tag, "input", 6);
+}
diff --git a/blankie/serializer.h b/blankie/serializer.h
new file mode 100644
index 0000000..36193ba
--- /dev/null
+++ b/blankie/serializer.h
@@ -0,0 +1,40 @@
+#pragma once
+
+#include <string>
+#include <vector>
+#include <variant>
+#include <utility>
+
+namespace blankie {
+namespace html {
+
+struct Element;
+struct HTMLString {
+    HTMLString() = default;
+    explicit HTMLString(std::string str_) : str(std::move(str_)) {}
+    HTMLString& operator=(std::string str_) {
+        this->str = std::move(str_);
+        return *this;
+    }
+
+    std::string str;
+};
+
+typedef std::pair<const char*, std::string> Attribute;
+typedef std::variant<Element, const char*, std::string, HTMLString> Node;
+
+struct Element {
+    const char* tag;
+    std::vector<Attribute> attributes;
+    std::vector<Node> nodes;
+
+    Element(const char* tag_) : tag(tag_) {}
+    Element(const char* tag_, std::vector<Node> nodes_)
+        : tag(tag_), nodes(std::move(nodes_)) {}
+    Element(const char* tag_, std::vector<Attribute> attributes_, std::vector<Node> nodes_)
+        : tag(tag_), attributes(std::move(attributes_)), nodes(std::move(nodes_)) {}
+    std::string serialize() const;
+};
+
+} // namespace html
+} // namespace blankie
diff --git a/client.cpp b/client.cpp
new file mode 100644
index 0000000..1c9c81f
--- /dev/null
+++ b/client.cpp
@@ -0,0 +1,159 @@
+#include <cassert>
+#include <stdexcept>
+#include <nlohmann/json.hpp>
+
+#include "client.h"
+#include "models.h"
+
+MastodonClient mastodon_client;
+
+static void share_lock(CURL* curl, curl_lock_data data, curl_lock_access access, void* clientp);
+static void share_unlock(CURL* curl, curl_lock_data data, void* clientp);
+static size_t curl_write_cb(char* ptr, size_t size, size_t nmemb, void* userdata);
+
+template<typename A>
+void setopt(CURLSH* share, CURLSHoption option, A parameter) {
+    CURLSHcode code = curl_share_setopt(share, option, parameter);
+    if (code) {
+        throw CurlShareException(code);
+    }
+}
+
+template<typename A>
+void setopt(CURL* curl, CURLoption option, A parameter) {
+    CURLcode code = curl_easy_setopt(curl, option, parameter);
+    if (code) {
+        throw CurlException(code);
+    }
+}
+
+
+MastodonClient::MastodonClient() {
+    this->_share = curl_share_init();
+    if (!this->_share) {
+        throw std::bad_alloc();
+    }
+
+    try {
+        setopt(this->_share, CURLSHOPT_SHARE, CURL_LOCK_DATA_DNS);
+        setopt(this->_share, CURLSHOPT_SHARE, CURL_LOCK_DATA_SSL_SESSION);
+        setopt(this->_share, CURLSHOPT_SHARE, CURL_LOCK_DATA_CONNECT);
+        setopt(this->_share, CURLSHOPT_SHARE, CURL_LOCK_DATA_PSL);
+        setopt(this->_share, CURLSHOPT_SHARE, CURL_LOCK_DATA_HSTS);
+
+        setopt(this->_share, CURLSHOPT_LOCKFUNC, share_lock);
+        setopt(this->_share, CURLSHOPT_UNLOCKFUNC, share_unlock);
+        setopt(this->_share, CURLSHOPT_USERDATA, this->_share_locks);
+    } catch (const std::exception& e) {
+        curl_share_cleanup(this->_share);
+        throw;
+    }
+
+    int err = pthread_key_create(&this->_easy_key, curl_easy_cleanup);
+    if (err) {
+        curl_share_cleanup(this->_share);
+        throw std::system_error(err, std::generic_category(), "pthread_key_create()");
+    }
+}
+
+MastodonClient::~MastodonClient() {
+    curl_share_cleanup(this->_share);
+
+    int err = pthread_key_delete(this->_easy_key);
+    if (err) {
+        perror("pthread_key_delete()");
+    }
+}
+
+std::optional<Account> MastodonClient::get_account_by_username(const std::string& host, const std::string& username) {
+    using namespace std::string_literals;
+
+    try {
+        std::string resp = this->_send_request("https://"s + host + "/api/v1/accounts/lookup?acct=" + username);
+        return nlohmann::json::parse(std::move(resp));
+    } catch (const CurlException& e) {
+        if (e.code != CURLE_HTTP_RETURNED_ERROR || this->_response_status_code() != 404) {
+            throw;
+        }
+
+        return std::nullopt;
+    }
+}
+
+CURL* MastodonClient::_get_easy() {
+    CURL* curl = pthread_getspecific(this->_easy_key);
+    if (!curl) {
+        curl = curl_easy_init();
+        if (!curl) {
+            throw std::bad_alloc();
+        }
+
+        try {
+            setopt(curl, CURLOPT_SHARE, this->_share);
+            setopt(curl, CURLOPT_FAILONERROR, 1L);
+        } catch (const std::exception& e) {
+            curl_easy_cleanup(curl);
+            throw;
+        }
+
+        int err = pthread_setspecific(this->_easy_key, curl);
+        if (err) {
+            curl_easy_cleanup(curl);
+            throw std::system_error(err, std::generic_category(), "pthread_setspecific()");
+        }
+    }
+
+    return curl;
+}
+
+std::string MastodonClient::_send_request(const std::string& url) {
+    std::string res;
+    CURL* curl = this->_get_easy();
+
+    setopt(curl, CURLOPT_URL, url.c_str());
+    setopt(curl, CURLOPT_WRITEFUNCTION, curl_write_cb);
+    setopt(curl, CURLOPT_WRITEDATA, &res);
+    CURLcode code = curl_easy_perform(curl);
+    if (code) {
+        throw CurlException(code);
+    }
+
+    return res;
+}
+
+long MastodonClient::_response_status_code() {
+    long response_code;
+    CURLcode code = curl_easy_getinfo(this->_get_easy(), CURLINFO_RESPONSE_CODE, &response_code);
+    if (code) {
+        throw CurlException(code);
+    }
+    return response_code;
+}
+
+
+static void share_lock(CURL* curl, curl_lock_data data, curl_lock_access access, void* clientp) {
+    (void)curl;
+    (void)access;
+
+    std::mutex* mutexes = reinterpret_cast<std::mutex*>(clientp);
+    assert(CURL_LOCK_DATA_LAST > data);
+    mutexes[data].lock();
+}
+
+static void share_unlock(CURL* curl, curl_lock_data data, void* clientp) {
+    (void)curl;
+
+    std::mutex* mutexes = reinterpret_cast<std::mutex*>(clientp);
+    assert(CURL_LOCK_DATA_LAST > data);
+    mutexes[data].unlock();
+}
+
+static size_t curl_write_cb(char* ptr, size_t size, size_t nmemb, void* userdata) {
+    size_t realsize = size * nmemb;
+    std::string* str = reinterpret_cast<std::string*>(userdata);
+
+    // XXX should we bother with exceptions
+    str->append(ptr, realsize);
+
+    return realsize;
+}
diff --git a/client.h b/client.h
new file mode 100644
index 0000000..0580df5
--- /dev/null
+++ b/client.h
@@ -0,0 +1,65 @@
+#pragma once
+
+#include <mutex>
+#include <optional>
+#include <exception>
+#include <pthread.h>
+
+#include <curl/curl.h>
+struct Account; // forward declaration from models.h
+
+class CurlException : public std::exception {
+public:
+    CurlException(CURLcode code_) : code(code_) {}
+
+    const char* what() const noexcept {
+        return curl_easy_strerror(this->code);
+    }
+
+    CURLcode code;
+};
+
+class CurlShareException : public std::exception {
+public:
+    CurlShareException(CURLSHcode code_) : code(code_) {}
+
+    const char* what() const noexcept {
+        return curl_share_strerror(this->code);
+    }
+
+    CURLSHcode code;
+};
+
+class MastodonClient {
+public:
+    MastodonClient(const MastodonClient&&) = delete;
+    MastodonClient& operator=(const MastodonClient&&) = delete;
+
+    MastodonClient();
+    ~MastodonClient();
+
+    static void init() {
+        CURLcode code = curl_global_init(CURL_GLOBAL_ALL);
+        if (code) {
+            throw CurlException(code);
+        }
+    }
+
+    static void cleanup() {
+        curl_global_cleanup();
+    }
+
+    std::optional<Account> get_account_by_username(const std::string& host, const std::string& username);
+
+private:
+    CURL* _get_easy();
+    std::string _send_request(const std::string& url);
+    long _response_status_code();
+
+    std::mutex _share_locks[CURL_LOCK_DATA_LAST];
+
+    CURLSH* _share = nullptr;
+    pthread_key_t _easy_key;
+};
+
+extern MastodonClient mastodon_client;
diff --git a/config.cpp b/config.cpp
new file mode 100644
index 0000000..abd8370
--- /dev/null
+++ b/config.cpp
@@ -0,0 +1,56 @@
+#include <stdexcept>
+#include <nlohmann/json.hpp>
+
+#include "file.h"
+#include "config.h"
+
+Config config;
+
+void load_config(const char* path) {
+    File config_file(path, "r");
+    config = nlohmann::json::parse(config_file.get());
+}
+
+RedisConfig get_redis_config(const nlohmann::json& j) {
+    using namespace std::string_literals;
+
+    RedisConfig redis_config;
+    const nlohmann::json& connection = j.at("connection");
+    const std::string& connection_type = connection.at("type").get_ref<const std::string&>();
+    if (connection_type == "ip") {
+        redis_config.connection_method = IPConnection{
+            connection.at("address").get<std::string>(),
+            connection.at("port").get<int>()
+        };
+    } else if (connection_type == "unix") {
+        redis_config.connection_method = UnixConnection{connection.at("unix").get<std::string>()};
+    } else {
+        throw std::invalid_argument("Unknown redis connection type: "s + connection_type);
+    }
+
+    if (j.at("username").is_string()) {
+        redis_config.username = j["username"].get<std::string>();
+    }
+    if (j.at("password").is_string()) {
+        redis_config.password = j["password"].get<std::string>();
+    }
+
+    return redis_config;
+}
+
+void from_json(const nlohmann::json& j, Config& conf) {
+    using namespace std::string_literals;
+
+    j.at("bind_host").get_to(conf.bind_host);
+    j.at("bind_port").get_to(conf.bind_port);
+    if (conf.bind_port < 0) {
+        throw std::invalid_argument("Invalid port to bind to: "s + std::to_string(conf.bind_port));
+    }
+
+    if (j.at("canonical_origin").is_string()) {
+        conf.canonical_origin = j["canonical_origin"].get<std::string>();
+    }
+    if (j.at("redis").at("enabled").get<bool>()) {
+        conf.redis_config = get_redis_config(j["redis"]);
+    }
+}
diff --git a/config.h b/config.h
new file mode 100644
index 0000000..88d55d5
--- /dev/null
+++ b/config.h
@@ -0,0 +1,32 @@
+#pragma once
+
+#include <string>
+#include <variant>
+#include <optional>
+#include <nlohmann/json_fwd.hpp>
+
+struct IPConnection {
+    std::string address;
+    int port;
+};
+struct UnixConnection {
+    std::string unix;
+};
+
+struct RedisConfig {
+    std::variant<IPConnection, UnixConnection> connection_method;
+    std::optional<std::string> username;
+    std::optional<std::string> password;
+};
+
+struct Config {
+    std::string bind_host = "127.0.0.1";
+    int bind_port = 8080;
+    std::optional<std::string> canonical_origin;
+    std::optional<RedisConfig> redis_config;
+};
+
+extern Config config;
+
+void load_config(const char* path);
+void from_json(const nlohmann::json& j, Config& conf);
diff --git a/example_config.json b/example_config.json
new file mode 100644
index 0000000..2da2e00
--- /dev/null
+++ b/example_config.json
@@ -0,0 +1,16 @@
+{
+    "bind_host": "127.0.0.1",
+    "bind_port": 8080,
+    "canonical_origin": null,
+    "redis": {
+        "enabled": true,
+        "connection": {
+            "type": "ip",
+            "address": "127.0.0.1",
+            "port": 6379,
+            "unix": "/path/to/redis.sock"
+        },
+        "username": null,
+        "password": "one of the passwords of all time"
+    }
+}
diff --git a/file.h b/file.h
new file mode 100644
index 0000000..daf43e4
--- /dev/null
+++ b/file.h
@@ -0,0 +1,61 @@
+#pragma once
+
+#include <cstdio>
+#include <system_error>
+
+static void try_close(FILE* file);
+
+class File {
+public:
+    // https://stackoverflow.com/a/2173764
+    File(const File&) = delete;
+    File& operator=(const File&) = delete;
+
+    inline File(File&& other) {
+        try_close(this->_file);
+        this->_file = other._file;
+        other._file = nullptr;
+    }
+    inline File& operator=(File&& other) {
+        if (this == &other) {
+            return *this;
+        }
+
+        try_close(this->_file);
+        this->_file = other._file;
+        other._file = nullptr;
+
+        return *this;
+    }
+
+    File(const char* __restrict path, const char* __restrict mode) {
+        this->_file = fopen(path, mode);
+        if (!this->_file) {
+            throw std::system_error(errno, std::generic_category(), "fopen()");
+        }
+    }
+    ~File() {
+        try_close(this->_file);
+    }
+
+    void write(const char* data, size_t length) {
+        if (fwrite(data, 1, length, this->_file) != length) {
+            throw std::system_error(errno, std::generic_category(), "fwrite()");
+        }
+    }
+    inline void write(const std::string& str) {
+        this->write(str.data(), str.size());
+    }
+    inline constexpr FILE* get() const noexcept {
+        return this->_file;
+    }
+
+protected:
+    FILE* _file = nullptr;
+};
+
+static void try_close(FILE* file) {
+    if (file && fclose(file)) {
+        perror("fclose()");
+    }
+}
diff --git a/hiredis_wrapper.cpp b/hiredis_wrapper.cpp
new file mode 100644
index 0000000..dfa94ec
--- /dev/null
+++ b/hiredis_wrapper.cpp
@@ -0,0 +1,128 @@
+#include "hiredis_wrapper.h"
+
+Redis::Redis(const std::string& address, int port) {
+    this->_context = redisConnect(address.c_str(), port);
+    if (!this->_context) {
+        throw std::bad_alloc();
+    }
+    if (this->_context->err) {
+        RedisException e(this->_context->errstr);
+        redisFree(this->_context);
+        throw e;
+    }
+}
+Redis::Redis(const std::string& unix) {
+    this->_context = redisConnectUnix(unix.c_str());
+    if (!this->_context) {
+        throw std::bad_alloc();
+    }
+    if (this->_context->err) {
+        RedisException e(this->_context->errstr);
+        redisFree(this->_context);
+        throw e;
+    }
+}
+Redis::~Redis() {
+    redisFree(this->_context);
+}
+
+void Redis::auth(const std::string& username, const std::string& password) {
+    RedisReply reply = this->command("AUTH %s %s", username.c_str(), password.c_str());
+    if (reply->type == REDIS_REPLY_STATUS) {
+        // good :D
+    } else {
+        throw std::runtime_error("AUTH gave an unexpected return type");
+    }
+}
+void Redis::auth(const std::string& password) {
+    RedisReply reply = this->command("AUTH %s", password.c_str());
+    if (reply->type == REDIS_REPLY_STATUS) {
+        // good :D
+    } else {
+        throw std::runtime_error("AUTH gave an unexpected return type");
+    }
+}
+
+time_t Redis::ttl(const std::string& key) {
+    RedisReply reply = this->command("TTL %s", key.c_str());
+    if (reply->type == REDIS_REPLY_INTEGER) {
+        return reply->integer;
+    } else {
+        throw std::runtime_error("TTL gave an unexpected return type");
+    }
+}
+
+bool Redis::expire(const std::string& key, time_t expiry) {
+    RedisReply reply = this->command("EXPIRE %s %d", key.c_str(), expiry);
+
+    if (reply->type == REDIS_REPLY_INTEGER) {
+        return reply->integer == 1;
+    } else {
+        throw std::runtime_error("EXPIRE gave an unexpected return type");
+    }
+}
+
+bool Redis::expire_nx(const std::string& key, time_t expiry) {
+    if (this->_fake_expire_nx) {
+        time_t current_expiry = this->ttl(key);
+        if (current_expiry < 0) {
+            return this->expire(key, expiry);
+        }
+        return false;
+    }
+
+    RedisReply reply(nullptr, freeReplyObject);
+    try{
+        reply = this->command("EXPIRE %s %d NX", key.c_str(), expiry);
+    } catch (const RedisException& e) {
+        if (e.error == "ERR wrong number of arguments for 'expire' command") {
+            this->_fake_expire_nx = true;
+            return this->expire_nx(key, expiry);
+        }
+        throw;
+    }
+
+    if (reply->type == REDIS_REPLY_INTEGER) {
+        return reply->integer == 1;
+    } else {
+        throw std::runtime_error("EXPIRE NX gave an unexpected return type");
+    }
+}
+
+std::optional<std::string> Redis::get(const std::string& key) {
+    RedisReply reply = this->command("GET %s", key.c_str());
+    if (reply->type == REDIS_REPLY_STRING) {
+        return std::string(reply->str, reply->len);
+    } else if (reply->type == REDIS_REPLY_NIL) {
+        return std::nullopt;
+    } else {
+        throw std::runtime_error("GET gave an unexpected return type");
+    }
+}
+void Redis::set(const std::string& key, const std::string& value, time_t expiry) {
+    RedisReply reply = this->command("SET %s %s EX %d", key.c_str(), value.c_str(), expiry);
+    if (reply->type == REDIS_REPLY_STATUS) {
+        // good :D
+    } else {
+        throw std::runtime_error("SET gave an unexpected return type");
+    }
+}
+
+std::optional<std::string> Redis::hget(const std::string& key, const std::string& field) {
+    RedisReply reply = this->command("HGET %s %s", key.c_str(), field.c_str());
+    if (reply->type == REDIS_REPLY_STRING) {
+        return std::string(reply->str, reply->len);
+    } else if (reply->type == REDIS_REPLY_NIL) {
+        return std::nullopt;
+    } else {
+        throw std::runtime_error("HGET gave an unexpected return type");
+    }
+}
+void Redis::hset(const std::string& key, const std::string& field, const std::string& value) {
+    RedisReply reply = this->command("HSET %s %s %s", key.c_str(), field.c_str(), value.c_str());
+    if (reply->type == REDIS_REPLY_INTEGER) {
+        // good :D
+    } else {
+        throw std::runtime_error("SET gave an unexpected return type");
+    }
+}
diff --git a/hiredis_wrapper.h b/hiredis_wrapper.h
new file mode 100644
index 0000000..8f3473b
--- /dev/null
+++ b/hiredis_wrapper.h
@@ -0,0 +1,73 @@
+#pragma once
+
+#include <mutex>
+#include <string>
+#include <memory>
+#include <optional>
+#include <exception>
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wpragmas"
+#pragma GCC diagnostic ignored "-Wc99-extensions"
+#pragma GCC diagnostic ignored "-Wconversion"
+#pragma GCC diagnostic ignored "-Wpedantic"
+#include <hiredis.h>
+#pragma GCC diagnostic pop
+
+class RedisException : public std::exception {
+public:
+    RedisException(const char* error_) : error(error_) {}
+    RedisException(const char* error_, size_t length) : error(error_, length) {}
+
+    const char* what() const noexcept {
+        return this->error.c_str();
+    }
+
+    std::string error;
+};
+
+using RedisReply = std::unique_ptr<redisReply, decltype(&freeReplyObject)>;
+
+class Redis {
+public:
+    Redis(const Redis&) = delete;
+    Redis operator=(const Redis&) = delete;
+
+    Redis(const std::string& address, int port);
+    Redis(const std::string& unix);
+    ~Redis();
+
+    template<typename... Args>
+    RedisReply command(const char* format, Args... args) {
+        std::lock_guard<std::mutex> guard(this->_mutex);
+        redisReply* raw_reply = static_cast<redisReply*>(redisCommand(this->_context, format, args...));
+        if (!raw_reply) {
+            throw RedisException(this->_context->errstr);
+        }
+
+        RedisReply reply(raw_reply, freeReplyObject);
+        if (reply->type == REDIS_REPLY_ERROR) {
+            throw RedisException(reply->str, reply->len);
+        }
+        return reply;
+    }
+
+    void auth(const std::string& username, const std::string& password);
+    void auth(const std::string& password);
+
+    time_t ttl(const std::string& key);
+    bool expire(const std::string& key, time_t expiry);
+    bool expire_nx(const std::string& key, time_t expiry);
+
+    std::optional<std::string> get(const std::string& key);
+    void set(const std::string& key, const std::string& value, time_t expiry);
+
+    std::optional<std::string> hget(const std::string& key, const std::string& field);
+    void hset(const std::string& key, const std::string& field, const std::string& value);
+
+private:
+    redisContext* _context;
+    std::mutex _mutex;
+
+    bool _fake_expire_nx = false;
+};
diff --git a/main.cpp b/main.cpp
new file mode 100644
index 0000000..195949f
--- /dev/null
+++ b/main.cpp
@@ -0,0 +1,92 @@
+#include <cstdio>
+#include <httplib/httplib.h>
+
+#include "config.h"
+#include "client.h"
+#include "servehelper.h"
+#include "routes/routes.h"
+
+#define DOMAIN_RE "(?:[a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,}"
+// https://docs.joinmastodon.org/methods/accounts/#422-unprocessable-entity
+#define USERNAME_RE "[a-zA-Z0-9_]+"
+#define ACCT_RE USERNAME_RE "(?:@" DOMAIN_RE ")?"
+
+int main(int argc, char** argv) {
+    if (argc != 2) {
+        fprintf(stderr, "Usage: %s <path/to/config/file.json>\n", argc > 0 ? argv[0] : "coyote");
+        return 1;
+    }
+
+    if (setenv("TZ", "UTC", true)) {
+        perror("Failed to set TZ=UTC: setenv()");
+        return 1;
+    }
+
+    try {
+        load_config(argv[1]);
+    } catch (const std::exception& e) {
+        fprintf(stderr, "Failed to load config: %s\n", e.what());
+        return 1;
+    }
+
+    MastodonClient::init();
+    atexit(MastodonClient::cleanup);
+
+    httplib::Server server;
+
+//    server.Get("/", [&](const httplib::Request& req, httplib::Response& res) {
+//        home_route(req, res, config);
+//    });
+    server.Get("/style.css", css_route);
+    server.Get("/(" DOMAIN_RE ")/@(" ACCT_RE ")(|/with_replies|/media)", user_route);
+    server.Get("/(" DOMAIN_RE ")/users/(" ACCT_RE ")(|/with_replies|/media)", [](const httplib::Request& req, httplib::Response& res) {
+        using namespace std::string_literals;
+
+        serve_redirect(req, res, "/"s + req.matches.str(1) + "/@" + req.matches.str(2) + req.matches.str(3), true);
+    });
+
+#ifndef NDEBUG
+    server.Get("/debug/exception/known", [](const httplib::Request& req, httplib::Response& res) {
+        throw std::runtime_error("awoo");
+    });
+    server.Get("/debug/exception/unknown", [](const httplib::Request& req, httplib::Response& res) {
+        throw "cope";
+    });
+#endif
+    server.Get(".*", [&](const httplib::Request& req, httplib::Response& res) {
+        res.status = 404;
+        serve_error(req, res, "404: Page not found");
+    });
+    server.set_exception_handler([&](const httplib::Request& req, httplib::Response& res, std::exception_ptr ep) {
+        res.status = 500;
+        try {
+            std::rethrow_exception(ep);
+        } catch (const std::exception& e) {
+            fprintf(stderr, "Exception thrown on %s: %s\n", req.path.c_str(), e.what());
+            serve_error(req, res, "500: Internal server error", std::nullopt, e.what());
+        } catch (...) {
+            fprintf(stderr, "Exception thrown on %s: Unknown exception\n", req.path.c_str());
+            serve_error(req, res, "500: Internal server error", std::nullopt, "Unknown exception");
+        }
+    });
+
+    if (config.bind_port != 0) {
+        if (!server.bind_to_port(config.bind_host, config.bind_port)) {
+            fprintf(stderr, "Failed to bind to %s:%d\n", config.bind_host.c_str(), config.bind_port);
+            return 1;
+        }
+    } else {
+        int port = server.bind_to_any_port(config.bind_host);
+        if (port == -1) {
+            fprintf(stderr, "Failed to bind to %s:<any>\n", config.bind_host.c_str());
+            return 1;
+        }
+        config.bind_port = port;
+    }
+    printf("Listening on %s:%d...\n", config.bind_host.c_str(), config.bind_port);
+
+    if (!server.listen_after_bind()) {
+        fprintf(stderr, "Failed to listen on %s:%d\n", config.bind_host.c_str(), config.bind_port);
+        return 1;
+    }
+}
diff --git a/models.cpp b/models.cpp
new file mode 100644
index 0000000..698aa81
--- /dev/null
+++ b/models.cpp
@@ -0,0 +1,81 @@
+#include <ctime>
+#include <regex>
+#include <stdexcept>
+#include <system_error>
+#include <nlohmann/json.hpp>
+
+#include "models.h"
+#include "numberhelper.h"
+
+using json = nlohmann::json;
+static time_t parse_rfc3339(const std::string& str);
+
+
+void from_json(const json& j, Emoji& emoji) {
+    j.at("shortcode").get_to(emoji.shortcode);
+    j.at("url").get_to(emoji.url);
+}
+
+void from_json(const json& j, AccountField& field) {
+    j.at("name").get_to(field.name);
+    field.value_html = j.at("value").get<std::string>();
+    if (j.at("verified_at").is_null()) {
+        field.verified_at = -1;
+    } else {
+        field.verified_at = parse_rfc3339(j["verified_at"].get_ref<const std::string&>());
+    }
+}
+
+static std::regex host_regex(R"EOF(https?://([a-z0-9-.]+)/.+)EOF", std::regex::ECMAScript | std::regex::icase);
+void from_json(const json& j, Account& account) {
+    using namespace std::string_literals;
+
+    j.at("id").get_to(account.id);
+    j.at("username").get_to(account.username);
+    j.at("display_name").get_to(account.display_name);
+    account.created_at = parse_rfc3339(j.at("created_at").get_ref<const std::string&>());
+    account.note_html = j.at("note").get<std::string>();
+    j.at("avatar").get_to(account.avatar);
+    j.at("header").get_to(account.header);
+    j.at("followers_count").get_to(account.followers_count);
+    j.at("following_count").get_to(account.following_count);
+    j.at("statuses_count").get_to(account.statuses_count);
+    j.at("emojis").get_to(account.emojis);
+    j.at("fields").get_to(account.fields);
+
+    std::smatch sm;
+    const std::string& url = j.at("url").get_ref<const std::string&>();
+    if (!std::regex_match(url, sm, host_regex)) {
+        throw std::runtime_error("failed to find host in url: "s + url);
+    }
+    account.domain_name = sm.str(1);
+}
+
+
+static std::regex rfc3339_re(R"EOF((\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.\d+)?(?:(Z)|([+-]\d{2}):(\d{2})))EOF", std::regex::ECMAScript | std::regex::icase);
+time_t parse_rfc3339(const std::string& str) {
+    using namespace std::string_literals;
+
+    std::smatch sm;
+    if (!std::regex_match(str, sm, rfc3339_re)) {
+        throw std::invalid_argument("unknown date format: "s + str);
+    }
+
+    struct tm tm = {
+        .tm_sec    = to_int(sm.str(6)),
+        .tm_min    = to_int(sm.str(5)),
+        .tm_hour   = to_int(sm.str(4)),
+
+        .tm_mday   = to_int(sm.str(3)),
+        .tm_mon    = to_int(sm.str(2)) - 1,
+        .tm_year   = to_int(sm.str(1)) - 1900,
+
+        .tm_isdst  = -1,
+        .tm_gmtoff = !sm.str(7).empty() ? 0 : to_int(sm.str(8)) * 60 * 60 + to_int(sm.str(9)) * 60,
+    };
+    time_t time = mktime(&tm);
+    if (time == -1) {
+        throw std::system_error(errno, std::generic_category(), "mktime()");
+    }
+    return time;
+}
diff --git a/models.h b/models.h
new file mode 100644
index 0000000..a71b1eb
--- /dev/null
+++ b/models.h
@@ -0,0 +1,43 @@
+#pragma once
+
+#include <string>
+#include <vector>
+#include <nlohmann/json_fwd.hpp>
+
+#include "blankie/serializer.h"
+
+enum PostSortingMethod {
+    Posts = 0,
+    PostsAndReplies,
+    Media,
+};
+
+struct Emoji {
+    std::string shortcode;
+    std::string url;
+};
+
+struct AccountField {
+    std::string name;
+    blankie::html::HTMLString value_html;
+    time_t verified_at; // negative is not verified
+};
+struct Account {
+    std::string id;
+    std::string username;
+    std::string domain_name;
+    std::string display_name;
+    time_t created_at;
+    blankie::html::HTMLString note_html;
+    std::string avatar;
+    std::string header;
+    uint64_t followers_count;
+    uint64_t following_count;
+    uint64_t statuses_count;
+    std::vector<Emoji> emojis;
+    std::vector<AccountField> fields;
+};
+
+void from_json(const nlohmann::json& j, Emoji& emoji);
+void from_json(const nlohmann::json& j, AccountField& field);
+void from_json(const nlohmann::json& j, Account& account);
diff --git a/numberhelper.cpp b/numberhelper.cpp
new file mode 100644
index 0000000..0e10b26
--- /dev/null
+++ b/numberhelper.cpp
@@ -0,0 +1,31 @@
+#include <climits>
+#include <stdexcept>
+
+#include "numberhelper.h"
+
+unsigned long long to_ull(const std::string& str) {
+    char* endptr;
+
+    errno = 0;
+    unsigned long long ret = strtoull(str.c_str(), &endptr, 10);
+    if (ret > ULLONG_MAX && errno == ERANGE) {
+        throw std::overflow_error(str + " is too big");
+    } else if (endptr[0] != '\0') {
+        throw std::invalid_argument(str + " has trailing text");
+    }
+    return ret;
+}
+
+int to_int(const std::string& str) {
+    char* endptr;
+
+    long ret = strtol(str.c_str(), &endptr, 10);
+    if (ret > INT_MAX) {
+        throw std::overflow_error(str + " is too big");
+    } else if (ret < INT_MIN) {
+        throw std::underflow_error(str + " is too small");
+    } else if (endptr[0] != '\0') {
+        throw std::invalid_argument(str + " has trailing text");
+    }
+    return static_cast<int>(ret);
+}
diff --git a/numberhelper.h b/numberhelper.h
new file mode 100644
index 0000000..9c153a1
--- /dev/null
+++ b/numberhelper.h
@@ -0,0 +1,7 @@
+#pragma once
+
+#include <string>
+#include <cstdlib>
+
+unsigned long long to_ull(const std::string& str);
+int to_int(const std::string& str);
diff --git a/routes/css.cpp b/routes/css.cpp
new file mode 100644
index 0000000..55f3b23
--- /dev/null
+++ b/routes/css.cpp
@@ -0,0 +1,142 @@
+#include <string>
+#include <FastHash.h>
+
+#include "routes.h"
+#include "../servehelper.h"
+
+static const constexpr char css[] = R"EOF(
+:root {
+    --bg-color: black;
+    --fg-color: white;
+    --font-size: 13pt;
+
+    --error-background-color: rgb(100, 0, 0);
+    --error-border-color: red;
+    --error-text-color: white;
+
+    --accent-color: #962AC3;
+    --bright-accent-color: #DE6DE6;
+}
+
+* {
+    margin: 0;
+    padding: 0;
+}
+html {
+    background-color: var(--bg-color);
+    color: var(--fg-color);
+    font-size: var(--font-size);
+    font-family: sans-serif;
+    padding: 10px;
+}
+p {
+    margin-top: 1em;
+    margin-bottom: 1em;
+}
+
+a {
+    color: var(--accent-color);
+}
+a:hover {
+    color: var(--bright-accent-color);
+}
+
+/* ERROR PAGE */
+.error {
+    text-align: center;
+    background-color: var(--error-background-color);
+    color: var(--error-text-color);
+    border-style: solid;
+    border-color: var(--error-border-color);
+}
+.error * {
+    margin: revert;
+    padding: revert;
+}
+
+/* USER PAGE */
+.user_page-header {
+    width: 100%;
+    max-height: 15em;
+    object-fit: cover;
+}
+
+.user_page-user_pfp {
+    display: flex;
+}
+.user_page-user_pfp img {
+    width: 7.5em;
+    height: 7.5em;
+}
+.user_page-user_pfp span {
+    margin-top: auto;
+    margin-bottom: auto;
+    margin-left: 0.5em;
+}
+
+/* https://stackoverflow.com/a/7354648 */
+@media (min-width: 801px) {
+    .user_page-user_description {
+        display: grid;
+        grid-template-columns: 1fr 1fr;
+    }
+}
+
+.user_page-user_bio {
+    line-height: 1.25;
+}
+
+.user_page-user_links {
+    height: fit-content;
+    width: fit-content;
+    text-align: left;
+    margin-top: 1em;
+    margin-bottom: 1em;
+    /* https://stackoverflow.com/a/5680823 */
+    border-collapse: collapse;
+}
+.user_page-user_links td {
+    padding-left: 1em;
+}
+.user_page-user_links .verified {
+    background-color: rgba(0, 150, 0, 0.3);
+}
+.user_page-user_links .verified td::after {
+    content: " ✓";
+    color: rgb(100, 255, 100);
+}
+
+.user_page-user_posts_nav {
+    display: grid;
+    grid-template-columns: 1fr 1fr 1fr;
+    text-align: center;
+}
+.user_page-user_posts_nav a {
+    text-decoration: none;
+}
+)EOF";
+// one for \0, one for trailing newline
+#define CSS_LEN sizeof(css) / sizeof(css[0]) - 2
+
+#if __cpp_constinit
+    #define CONSTINIT constinit
+#else
+    #define CONSTINIT
+#endif
+
+CONSTINIT const uint64_t css_hash = FastHash(css, CSS_LEN, 0);
+
+void css_route(const httplib::Request& req, httplib::Response& res) {
+    using namespace std::string_literals;
+
+    res.set_header("ETag", "\""s + std::to_string(css_hash) + '"');
+    res.set_header("Cache-Control", "max-age=31536000, immutable");
+
+    if (should_send_304(req, css_hash)) {
+        res.status = 304;
+        res.set_header("Content-Length", std::to_string(CSS_LEN));
+        res.set_header("Content-Type", "text/css");
+    } else {
+        res.set_content(css, CSS_LEN, "text/css");
+    }
+}
diff --git a/routes/routes.h b/routes/routes.h
new file mode 100644
index 0000000..d3efe3c
--- /dev/null
+++ b/routes/routes.h
@@ -0,0 +1,8 @@
+#pragma once
+
+#include <httplib/httplib.h>
+
+extern const uint64_t css_hash;
+
+void css_route(const httplib::Request& req, httplib::Response& res);
+void user_route(const httplib::Request& req, httplib::Response& res);
diff --git a/routes/user.cpp b/routes/user.cpp
new file mode 100644
index 0000000..157b95c
--- /dev/null
+++ b/routes/user.cpp
@@ -0,0 +1,129 @@
+#include "routes.h"
+#include "../servehelper.h"
+#include "../client.h"
+#include "../models.h"
+
+static const char* sorting_method_names[3] = {"Posts", "Posts and replies", "Media"};
+static const char* sorting_method_suffixes[3] = {"", "/with_replies", "/media"};
+static inline PostSortingMethod get_sorting_method(const std::string& method);
+
+static inline Element user_header(const Account& account, PostSortingMethod sorting_method);
+static inline Element user_link_field(const AccountField& field);
+static inline Element sorting_method_link(const Account& account, PostSortingMethod current_method, PostSortingMethod new_method);
+
+
+void user_route(const httplib::Request& req, httplib::Response& res) {
+    std::string server = req.matches.str(1);
+    std::string username = req.matches.str(2);
+    PostSortingMethod sorting_method = get_sorting_method(req.matches.str(3));
+
+    std::optional<Account> account;
+    try {
+        account = mastodon_client.get_account_by_username(server, username);
+    } catch (const std::exception& e) {
+        res.status = 500;
+        serve_error(req, res, "500: Internal server error", "Failed to fetch user information", e.what());
+        return;
+    }
+
+    if (!account) {
+        res.status = 404;
+        serve_error(req, res, "404: User not found");
+        return;
+    }
+
+    Element body("body", {
+        user_header(*account, sorting_method),
+    });
+    serve(req, res, account->display_name + " (" + account->username + '@' + account->domain_name + ')', std::move(body));
+}
+
+
+static inline PostSortingMethod get_sorting_method(const std::string& method) {
+    for (size_t i = 0; i < sizeof(sorting_method_suffixes) / sizeof(sorting_method_suffixes[0]); i++) {
+        if (method == sorting_method_suffixes[i]) {
+            return static_cast<PostSortingMethod>(i);
+        }
+    }
+
+    __builtin_unreachable();
+}
+
+
+static inline Element user_header(const Account& account, PostSortingMethod sorting_method) {
+    struct tm created_at;
+    char created_at_str[16];
+    gmtime_r(&account.created_at, &created_at);
+    strftime(created_at_str, 16, "%Y-%m-%d", &created_at);
+
+    Element user_links("table", {{"class", "user_page-user_links"}}, {});
+    user_links.nodes.reserve(account.fields.size());
+    for (const AccountField& i : account.fields) {
+        user_links.nodes.push_back(user_link_field(i));
+    }
+
+    Element header("header", {
+        Element("a", {{"href", account.header}}, {
+            Element("img", {{"class", "user_page-header"}, {"alt", "User header"}, {"src", account.header}}, {}),
+        }),
+        Element("div", {{"class", "user_page-user_pfp"}}, {
+            Element("a", {{"href", account.avatar}}, {
+                Element("img", {{"alt", "User profile picture"}, {"src", account.avatar}}, {}),
+            }),
+            Element("span", {
+                Element("b", {account.display_name}), " (", account.username, "@", account.domain_name, ")",
+                Element("br"),
+                Element("br"), Element("b", {"Joined: "}), std::string(created_at_str),
+                Element("br"),
+                Element("b", {std::to_string(account.statuses_count)}), " Posts", " / ",
+                Element("b", {std::to_string(account.following_count)}), " Following", " / ",
+                Element("b", {std::to_string(account.followers_count)}), " Followers",
+            }),
+        }),
+
+        Element("div", {{"class", "user_page-user_description"}}, {
+            Element("div", {{"class", "user_page-user_bio"}}, {account.note_html}),
+
+            std::move(user_links),
+        }),
+
+        Element("nav", {{"class", "user_page-user_posts_nav"}}, {
+            sorting_method_link(account, sorting_method, PostSortingMethod::Posts),
+            sorting_method_link(account, sorting_method, PostSortingMethod::PostsAndReplies),
+            sorting_method_link(account, sorting_method, PostSortingMethod::Media),
+        }),
+    });
+    return header;
+}
+
+static inline Element user_link_field(const AccountField& field) {
+    using namespace std::string_literals;
+
+    Element tr("tr", {
+        Element("th", {field.name}),
+        Element("td", {field.value_html}),
+    });
+    if (field.verified_at >= 0) {
+        struct tm verified_at;
+        char verified_at_str[32];
+        gmtime_r(&field.verified_at, &verified_at);
+        strftime(verified_at_str, 32, "%Y-%m-%d %H:%M:%S %Z", &verified_at);
+
+        tr.attributes = {{"class", "verified"}, {"title", "Verified at "s + verified_at_str}};
+    }
+
+    return tr;
+}
+
+static inline Element sorting_method_link(const Account& account, PostSortingMethod current_method, PostSortingMethod new_method) {
+    using namespace std::string_literals;
+    const char* method_name = sorting_method_names[new_method];
+
+    if (current_method == new_method) {
+        return Element("b", {method_name});
+    } else {
+        return Element("a", {{"href", "/"s + account.domain_name + "/@" + account.username + sorting_method_suffixes[new_method]}}, {
+            method_name,
+        });
+    }
+}
diff --git a/servehelper.cpp b/servehelper.cpp
new file mode 100644
index 0000000..0d9d02a
--- /dev/null
+++ b/servehelper.cpp
@@ -0,0 +1,155 @@
+#include <memory>
+#include <exception>
+#include <stdexcept>
+#include <FastHash.h>
+#include <curl/curl.h>
+
+#include "config.h"
+#include "servehelper.h"
+#include "routes/routes.h"
+
+class CurlUrlException : public std::exception {
+public:
+    CurlUrlException(CURLUcode code_) : code(code_) {}
+
+    const char* what() const noexcept {
+        return curl_url_strerror(this->code);
+    }
+
+    CURLUcode code;
+};
+
+
+void serve(const httplib::Request& req, httplib::Response& res, std::string title, Element element, Nodes extra_head) {
+    using namespace std::string_literals;
+
+    std::string css_url = get_origin(req) + "/style.css";
+    res.set_header("Content-Security-Policy", "default-src 'none'; img-src https:; media-src: https:; style-src "s + css_url);
+
+    Element head("head", {
+        Element("meta", {{"charset", "utf-8"}}, {}),
+        Element("title", {std::move(title)}),
+        Element("link", {{"rel", "stylesheet"}, {"href", std::move(css_url) + "?v=" + std::to_string(css_hash)}}, {}),
+        Element("meta", {{"name", "viewport"}, {"content", "width=device-width,initial-scale=1"}}, {})
+    });
+    head.nodes.reserve(head.nodes.size() + extra_head.size());
+    head.nodes.insert(head.nodes.end(), extra_head.begin(), extra_head.end());
+    std::string html = "<!DOCTYPE html>"s + Element("html", {
+        std::move(head),
+        std::move(element)
+    }).serialize();
+
+    uint64_t hash = FastHash(html.data(), html.size(), 0);
+    res.set_header("ETag", std::string(1, '"') + std::to_string(hash) + '"');
+
+    if (should_send_304(req, hash)) {
+        res.status = 304;
+        res.set_header("Content-Length", std::to_string(html.size()));
+        res.set_header("Content-Type", "text/html");
+    } else {
+        res.set_content(std::move(html), "text/html");
+    }
+}
+
+void serve_error(const httplib::Request& req, httplib::Response& res,
+        std::string title, std::optional<std::string> subtitle, std::optional<std::string> info) {
+
+    Element error_div("div", {{"class", "error"}}, {
+        Element("h2", {title})
+    });
+    if (subtitle) {
+        error_div.nodes.push_back(Element("p", {
+            std::move(*subtitle)
+        }));
+    }
+    if (info) {
+        error_div.nodes.push_back(Element("pre", {
+            Element("code", {std::move(*info)})
+        }));
+    }
+
+    Element body("body", {std::move(error_div)});
+    serve(req, res, std::move(title), std::move(body));
+}
+
+void serve_redirect(const httplib::Request& req, httplib::Response& res, std::string url, bool permanent) {
+    using namespace std::string_literals;
+
+    Element body("body", {
+        "Redirecting to ",
+        Element("a", {{"href", url}}, {url}),
+        "…"
+    });
+    res.set_redirect(url, permanent ? 301 : 302);
+    serve(req, res, "Redirecting to "s + std::move(url) + "…", std::move(body));
+}
+
+
+
+std::string get_origin(const httplib::Request& req) {
+    if (req.has_header("X-Canonical-Origin")) {
+        return req.get_header_value("X-Canonical-Origin");
+    }
+    if (config.canonical_origin) {
+        return *config.canonical_origin;
+    }
+
+    std::string origin = "http://";
+    if (req.has_header("Host")) {
+        origin += req.get_header_value("Host");
+    } else {
+        origin += config.bind_host;
+        if (config.bind_port != 80) {
+            origin += ':' + std::to_string(config.bind_port);
+        }
+    }
+    return origin;
+}
+
+std::string proxy_mastodon_url(const httplib::Request& req, const std::string& url_str) {
+    using CurlStr = std::unique_ptr<char, decltype(&curl_free)>;
+
+    std::unique_ptr<CURLU, decltype(&curl_url_cleanup)> url(curl_url(), curl_url_cleanup);
+    if (!url) {
+        throw std::bad_alloc();
+    }
+
+    CURLUcode code = curl_url_set(url.get(), CURLUPART_URL, url_str.c_str(), 0);
+    if (code) {
+        throw CurlUrlException(code);
+    }
+
+    auto get_part = [&](CURLUPart part) {
+        char* content;
+        CURLUcode code = curl_url_get(url.get(), part, &content, 0);
+        if (code) {
+            throw CurlUrlException(code);
+        }
+        return CurlStr(content, curl_free);
+    };
+    CurlStr host = get_part(CURLUPART_HOST);
+    CurlStr path = get_part(CURLUPART_PATH);
+    CurlStr query = get_part(CURLUPART_QUERY);
+    CurlStr fragment = get_part(CURLUPART_FRAGMENT);
+
+    std::string new_url = get_origin(req) + '/' + host.get() + path.get();
+    if (query) {
+        new_url += '?';
+        new_url += query.get();
+    }
+    if (fragment) {
+        new_url += '#';
+        new_url += fragment.get();
+    }
+    return new_url;
+}
+
+bool should_send_304(const httplib::Request& req, uint64_t hash) {
+    std::string header = req.get_header_value("If-None-Match");
+    if (header == "*") {
+        return true;
+    }
+
+    size_t pos = header.find(std::string(1, '"') + std::to_string(hash) + '"');
+    return pos != std::string::npos && (pos == 0 || header[pos - 1] != '/');
+}
diff --git a/servehelper.h b/servehelper.h
new file mode 100644
index 0000000..9b57d6c
--- /dev/null
+++ b/servehelper.h
@@ -0,0 +1,19 @@
+#pragma once
+
+#include <optional>
+
+#include <httplib/httplib.h>
+#include "blankie/serializer.h"
+
+using Element = blankie::html::Element;
+using Node = blankie::html::Node;
+using Nodes = std::vector<Node>;
+
+void serve(const httplib::Request& req, httplib::Response& res, std::string title, Element element, Nodes extra_head = {});
+void serve_error(const httplib::Request& req, httplib::Response& res,
+        std::string title, std::optional<std::string> subtitle = std::nullopt, std::optional<std::string> info = std::nullopt);
+void serve_redirect(const httplib::Request& req, httplib::Response& res, std::string url, bool permanent = false);
+
+std::string get_origin(const httplib::Request& req);
+std::string proxy_mastodon_url(const httplib::Request& req, const std::string& url_str);
+bool should_send_304(const httplib::Request& req, uint64_t hash);
diff --git a/thirdparty/FastHash.h b/thirdparty/FastHash.h
new file mode 100644
index 0000000..8902f21
--- /dev/null
+++ b/thirdparty/FastHash.h
@@ -0,0 +1,79 @@
+// https://github.com/KoneLinx/small_ECS/blob/master/FastHash.h
+// but slightly modified to abandon ranges
+
+// Copyright(C) 2021 Kobe Vrijsen <kobevrijsen@posteo.be>
+// 
+// A simple ECS example
+// 
+// This file is free software and distributed under the terms of the European Union
+// Public Lincense as published by the European Commision; either version 1.2 of the
+// License, or , at your option, any later version.
+
+/* The MIT License
+
+   Copyright (C) 2012 Zilong Tan (eric.zltan@gmail.com)
+   
+   Permission is hereby granted, free of charge, to any person
+   obtaining a copy of this software and associated documentation
+   files (the "Software"), to deal in the Software without
+   restriction, including without limitation the rights to use, copy,
+   modify, merge, publish, distribute, sublicense, and/or sell copies
+   of the Software, and to permit persons to whom the Software is
+   furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be
+   included in all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+   BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+   ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+   SOFTWARE.
+*/
+
+// Source: fast-hash https://github.com/ztanml/fast-hash (26 Nov 2021)
+// Changes: General uplift and providing a general constant hash for ranges
+
+#include <cstdint>
+#include <cstddef>
+
+#pragma once
+
+// Compression function for Merkle-Damgard construction.
+// This function is generated using the framework provided.
+//#define mix(h) ({
+//			(h) ^= (h) >> 23;
+//			(h) *= 0x2127599bf4325c37ULL;
+//			(h) ^= (h) >> 47; })
+
+constexpr uint64_t FastHash(const char* str, std::size_t size, uint64_t seed/*, uint64_t back = {}*/)
+{
+	auto const mix = [](uint64_t h)
+	{
+		h ^= h >> 23;
+		h *= 0x2127599bf4325c37ULL;
+		h ^= h >> 47;
+		return h;
+	};
+
+	const uint64_t m = 0x880355f21e6d1965ULL;
+
+	uint64_t h = seed ^ (size * m);
+
+	for (std::size_t i = 0; i < size; i++)
+	{
+		h ^= mix(static_cast<uint64_t>(str[i]));
+		h *= m;
+	}
+
+	//if (back != uint64_t())
+	//{
+	//	h ^= mix(back);
+	//	h *= m;
+	//}
+
+	return mix(h);
+}
diff --git a/thirdparty/httplib b/thirdparty/httplib
new file mode 160000
index 0000000..5ef4cfd
--- /dev/null
+++ b/thirdparty/httplib
@@ -0,0 +1 @@
+Subproject commit 5ef4cfd263309458afe27246d66f370e3b351faa