#include "routes.h"
#include "../numberhelper.h"
#include "../servehelper.h"
#include "../pixivclient.h"

static inline Element generate_header(const httplib::Request& req, const Config& config,
        const SearchResults& search_results, const std::string& query, const std::vector<std::string>& tags, const std::string& order,
        const std::vector<SearchSuggestion>& search_suggestions);
static inline Element generate_search_suggestions(const httplib::Request& req, const Config& config,
        const std::vector<std::string>& tags, const std::vector<SearchSuggestion>& search_suggestions, bool open_by_default);

static std::string tags_to_string(const std::unordered_map<std::string, std::string>& tag_translations, const std::vector<std::string>& tags);
static inline std::vector<std::string> split(const std::string& str, char c);
static inline std::string join(const std::vector<std::string>& items, char c);

void tags_route(const httplib::Request& req, httplib::Response& res, const Config& config, PixivClient& pixiv_client) {
    std::string query = blankie::murl::unescape(req.matches.str(1));
    std::string order = req.has_param("order") ? req.get_param_value("order") : "date_d";
    unsigned long long page = req.has_param("p") ? to_ull(req.get_param_value("p")) - 1 : 0;
    std::vector<std::string> tags = split(query, ' ');

    if (tags.empty()) {
        res.status = 400;
        serve_error(req, res, config, "400: Bad Request", "Empty search query");
        return;
    }

    SearchResults search_results;
    try {
        search_results = pixiv_client.search_illusts(query, page, order);
    } catch (const std::exception& e) {
        res.status = 500;
        serve_error(req, res, config, "500: Internal server error", "Failed to search for illusts", e.what());
        return;
    }
    std::vector<SearchSuggestion> search_suggestions;
    try {
        search_suggestions = pixiv_client.get_search_suggestions(tags.back());
    } catch (const std::exception& e) {
        res.status = 500;
        serve_error(req, res, config, "500: Internal server error", "Failed to get search suggestions", e.what());
        return;
    }

    Element body("body", {
        generate_header(req, config, search_results, query, tags, order, search_suggestions)
    });
    if (!search_results.illusts.illusts.empty()) {
        body.nodes.push_back(Element("br"));
        body.nodes.push_back(generate_illusts_pager(req, config, search_results.illusts, page, "illusts"));
    }
    serve(req, res, config, tags_to_string(std::move(search_results.tag_translations), std::move(tags)), std::move(body));
}



static inline Element generate_header(const httplib::Request& req, const Config& config,
        const SearchResults& search_results, const std::string& query, const std::vector<std::string>& tags, const std::string& order,
        const std::vector<SearchSuggestion>& search_suggestions) {
    auto sort_element = [&](const char* title, const char* new_order) {
        std::string url = get_origin(req, config) + "/tags/" + blankie::murl::escape(query) + "/illustrations?order=" + new_order;
        Element ret("a", {{"href", std::move(url)}}, {title});
        if (new_order == order) {
            ret = Element("b", {std::move(ret)});
        }
        return ret;
    };

    Element header("header", {{"class", "center"}}, {
        Element("form", {{"method", "get"}, {"action", get_origin(req, config) + "/search"}}, {
            Element("input", {{"name", "q"}, {"required", ""}, {"value", query}}, {}),
            " ",
            Element("button", {"Search for illustrations"})
        })
    });
    if (!search_suggestions.empty()) {
        header.nodes.push_back(generate_search_suggestions(req, config, tags, search_suggestions, search_results.illusts.total_pages <= 1));
    }
    header.nodes.push_back(Element("br"));

    if (search_results.illusts.total_illusts != 1) {
        header.nodes.push_back("There are ");
        header.nodes.push_back(std::to_string(search_results.illusts.total_illusts));
        header.nodes.push_back(" illustrations");
    } else {
        header.nodes.push_back("There is 1 illustration");
    }
    header.nodes.push_back(" of ");
    header.nodes.push_back(Element("b", {tags_to_string(search_results.tag_translations, tags)}));

    header.nodes.push_back(Element("br"));
    header.nodes.push_back("Sort by: ");
    header.nodes.push_back(sort_element("Newest", "date_d"));
    header.nodes.push_back(" ");
    header.nodes.push_back(sort_element("Oldest", "date"));

    return header;
}

static inline Element generate_search_suggestions(const httplib::Request& req, const Config& config,
        const std::vector<std::string>& tags, const std::vector<SearchSuggestion>& search_suggestions, bool open_by_default) {
    std::vector<blankie::html::Node> ul_nodes;
    ul_nodes.reserve(search_suggestions.size());
    for (const SearchSuggestion& search_suggestion : search_suggestions) {
        std::string text = search_suggestion.tag;
        if (search_suggestion.english_tag) {
            text += " (";
            text += *search_suggestion.english_tag;
            text += ')';
        }

        std::vector<std::string> new_tags = tags;
        new_tags.pop_back();
        new_tags.push_back(search_suggestion.tag);
        std::string url = get_origin(req, config) + "/tags/" + blankie::murl::escape(join(new_tags, ' '));

        ul_nodes.push_back(Element("li", {
            Element("a", {{"href", std::move(url)}}, {std::move(text)})
        }));
    }

    Element details("details", {
        Element("summary", {"Search suggestions"}),
        Element("ul", {{"class", "searchsuggestions"}}, ul_nodes)
    });
    if (open_by_default) {
        details.attributes.push_back({"open", ""});
    }

    return details;
}



static std::string tags_to_string(const std::unordered_map<std::string, std::string>& tag_translations, const std::vector<std::string>& tags) {
    std::string str;
    for (const std::string& tag : tags) {
        if (!str.empty()) {
            str += ' ';
        }
        str += '#';

        auto translated_tag = tag_translations.find(tag);
        str += translated_tag != tag_translations.cend() ? translated_tag->second : tag;
    }
    return str;
}

static inline std::vector<std::string> split(const std::string& str, char c) {
    std::vector<std::string> ret;
    size_t pos = 0;
    size_t last_pos = 0;

    while ((pos = str.find(c, pos)) != std::string::npos) {
        if (pos - last_pos > 0) {
            ret.push_back(str.substr(last_pos, pos - last_pos));
        }
        pos++;
        last_pos = pos;
    }
    if (str.size() > last_pos) {
        ret.push_back(str.substr(last_pos));
    }

    return ret;
}

static inline std::string join(const std::vector<std::string>& items, char c) {
    std::string ret;

    for (size_t i = 0; i < items.size(); i++) {
        if (i) {
            ret += c;
        }
        ret += items[i];
    }

    return ret;
}