#include <cstdio>
#include <httplib/httplib.h>

#include "config.h"
#include "client.h"
#include "hiredis_wrapper.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
// https://akko.erincandescent.net/@postmaster-emeritus
#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;
    }
    try {
        init_redis();
    } catch (const std::exception& e) {
        fprintf(stderr, "Failed to init redis: %s\n", e.what());
        return 1;
    }

    MastodonClient::init();
    atexit(MastodonClient::cleanup);

    httplib::Server server;
    server.set_payload_max_length(8192);

    server.Get("/", home_route);
    server.Get("/style.css", css_route);
    server.Get("/favicon.ico", [](const httplib::Request& req, httplib::Response& res) {
        res.status = 404;
        serve_error(req, res, "404: Page not found");
    });

    server.Get("/settings", user_settings_route);
    server.Post("/settings", user_settings_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) {
        serve_redirect(req, res, get_origin(req) + '/' + req.matches.str(1) + "/@" + req.matches.str(2) + req.matches.str(3), true);
    });

    server.Get("/(" DOMAIN_RE ")/@" ACCT_RE "/([a-zA-Z0-9]+)", status_route);
    server.Get("/(" DOMAIN_RE ")/users/(" ACCT_RE ")/statuses/([a-zA-Z0-9]+)", [](const httplib::Request& req, httplib::Response& res) {
        serve_redirect(req, res, get_origin(req) + '/' + req.matches.str(1) + "/@" + req.matches.str(2) + '/' + req.matches.str(3), true);
    });

    // protect against ..
    server.Get("/(" DOMAIN_RE ")/tags/(?!\\.|%2E|%2e)(.+)", tags_route);

    server.Get("/(" DOMAIN_RE ")/about", about_route);
    server.Get("/(" DOMAIN_RE ")/?", [](const httplib::Request& req, httplib::Response& res) {
        serve_redirect(req, res, get_origin(req) + '/' + req.matches.str(1) + "/about", false);
    });

    server.Get("/https://?(.+)", [](const httplib::Request& req, httplib::Response& res) {
        serve_redirect(req, res, get_origin(req) + '/' + req.matches.str(1), 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;
    }
}