#include "routes.h"
#include "../servehelper.h"
#include "../client.h"
#include "../models.h"
#include "../timeutils.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 httplib::Request& req, const std::string& server, const Account& account, PostSortingMethod sorting_method);
static inline Element user_link_field(const httplib::Request& req, const Account& account, const AccountField& field);
static inline Element sorting_method_link(const httplib::Request& req, const std::string& server, const Account& account, PostSortingMethod current_method, PostSortingMethod new_method);


void user_route(const httplib::Request& req, httplib::Response& res) {
    using namespace std::string_literals;

    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<std::string> max_id;
    if (req.has_param("max_id")) {
        max_id = req.get_param_value("max_id");
        if (max_id->empty() || max_id->find_first_not_of("0123456789") != std::string::npos) {
            res.status = 400;
            serve_error(req, res, "400: Bad Request", "Invalid max_id query paramter");
            return;
        }
    }

    std::optional<Account> account;
    std::vector<Post> pinned_posts, posts;
    try {
        account = mastodon_client.get_account_by_username(server, username);
        if (account) {
            if (sorting_method == PostSortingMethod::Posts && !max_id) {
                pinned_posts = mastodon_client.get_pinned_posts(server, account->id);
            }
            posts = mastodon_client.get_posts(server, account->id, sorting_method, max_id);
        }
    } 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(req, server, *account, sorting_method),
    });
    body.nodes.reserve(body.nodes.size() + 2 * (pinned_posts.size() + posts.size()) + 1);

    for (const Post& post : pinned_posts) {
        body.nodes.push_back(serialize_post(req, server, post, true));
        body.nodes.push_back(Element("hr"));
    }
    for (const Post& post : posts) {
        body.nodes.push_back(serialize_post(req, server, post));
        body.nodes.push_back(Element("hr"));
    }

    if (!posts.empty()) {
        body.nodes.push_back(Element("a", {{"class", "user_page-more_posts"}, {"href", "?max_id="s + posts[posts.size() - 1].id + "#user_posts_nav"}}, {"See more"}));
    } else if (max_id) {
        body.nodes.push_back(Element("p", {{"class", "user_page-more_posts"}}, {"There are no more posts"}));
    }

    serve(req, res, account->display_name + " (@" + account->acct() + ')', 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 httplib::Request& req, const std::string& server, const Account& account, PostSortingMethod sorting_method) {
    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(req, account, i));
    }

    Node view_on_original = !account.same_server
        ? Element("span", {" (", Element("a", {{"href", get_origin(req) + '/' + account.server + "/@" + account.username}}, {"View on original instance"}), ")"})
        : Node("");

    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-main_header"}}, {
            Element("a", {{"href", account.avatar}}, {
                Element("img", {{"class", "user_page-profile"}, {"alt", "User profile picture"}, {"src", account.avatar}}, {}),
            }),
            Element("span", {
                Element("b", {preprocess_html(req, account.emojis, account.display_name)}), account.bot ? " (bot)" : "", " (@", account.acct(), ")", view_on_original,
                Element("br"),
                Element("br"), Element("b", {"Joined: "}), short_time(account.created_at),
                Element("br"),
                Element("b", {std::to_string(account.statuses_count)}), " Posts", " / ",
                Element("b", {std::to_string(account.following_count)}), " Following", " / ",
                // https://chaosfem.tw/@Terra
                Element("b", {account.followers_count >= 0 ? std::to_string(account.followers_count) : "???"}), " Followers",
            }),
        }),

        Element("div", {{"class", "user_page-user_description"}}, {
            Element("div", {{"class", "user_page-user_bio"}}, {preprocess_html(req, account.server, account.emojis, account.note_html)}),

            std::move(user_links),
        }),

        Element("nav", {{"class", "user_page-user_posts_nav"}, {"id", "user_posts_nav"}}, {
            sorting_method_link(req, server, account, sorting_method, PostSortingMethod::Posts),
            sorting_method_link(req, server, account, sorting_method, PostSortingMethod::PostsAndReplies),
            sorting_method_link(req, server, account, sorting_method, PostSortingMethod::MediaOnly),
        }),
    });
    return header;
}

static inline Element user_link_field(const httplib::Request& req, const Account& account, const AccountField& field) {
    using namespace std::string_literals;

    Element tr("tr", {
        Element("th", {preprocess_html(req, account.emojis, field.name)}),
        Element("td", {preprocess_html(req, account.server, account.emojis, field.value_html)}),
    });
    if (field.verified_at >= 0) {
        tr.attributes = {{"class", "verified"}, {"title", "Verified at "s + full_time(field.verified_at)}};
    }

    return tr;
}

static inline Element sorting_method_link(const httplib::Request& req, const std::string& server, const Account& account, PostSortingMethod current_method, PostSortingMethod new_method) {
    const char* method_name = sorting_method_names[new_method];

    Element a("a", {{"href", get_origin(req) + '/' + server + "/@" + account.acct(false) + sorting_method_suffixes[new_method] + "#user_posts_nav"}}, {
        method_name,
    });
    if (current_method == new_method) {
        a.attributes.push_back({"class", "selected"});
    }
    return a;
}