#include <regex>

#include "blankie/murl.h"

#include "pixivmodels.h"
#include "numberhelper.h"

static inline std::optional<std::string> get_1920x960_cover_image(blankie::murl::Url url);
static inline std::optional<std::string> get_original_cover_image(blankie::murl::Url url, const nlohmann::json& cover_image);
static inline std::optional<std::string> get_original_profile_picture(blankie::murl::Url url);
static inline std::optional<std::string> get_360x360_illust_thumbnail(blankie::murl::Url url);
static inline std::optional<std::string> get_original_illust_image(blankie::murl::Url url);
static Images get_profile_pictures(const nlohmann::json& j);
static Images get_profile_pictures(const std::string& url);
static std::optional<std::pair<uint64_t, uint64_t>> get_thumbnail_size(blankie::murl::Url thumbnail_url, std::optional<std::pair<uint64_t, uint64_t>> original_size);
static Images get_illust_images(const nlohmann::json& image, std::optional<nlohmann::json> image_metadata);

const Image& Images::original_or_thumbnail() const {
    if (this->original) {
        return *this->original;
    }
    if (!this->thumbnails.empty()) {
        return this->thumbnails.back();
    }
    throw std::runtime_error("Images does not contain any images");
}

const Image& Images::thumbnail_or_original(size_t back) const {
    if (this->thumbnails.size() > back) {
        return this->thumbnails[this->thumbnails.size() - back - 1];
    }
    if (!this->thumbnails.empty()) {
        return this->thumbnails.back();
    }
    if (this->original) {
        return *this->original;
    }
    throw std::runtime_error("Images does not contain any images");
}

void from_json(const nlohmann::json& j, User& user) {
    using namespace std::string_literals;

    j.at("user_account").get_to(user.username);
    j.at("user_name").get_to(user.display_name);
    user.user_id = to_ull(j.at("user_id").get_ref<const nlohmann::json::string_t&>());

    if (j.contains("cover_image") && j["cover_image"].is_object()) {
        nlohmann::json cover_image = j["cover_image"];
        std::string c_720x360 = cover_image.at("profile_cover_image").at("720x360").get<std::string>();
        std::optional<std::string> original = get_original_cover_image(c_720x360, cover_image);
        std::optional<std::string> c_1920x960 = get_1920x960_cover_image(c_720x360);

        user.cover_images = {std::move(original), {std::move(c_720x360)}};
        if (c_1920x960) {
            user.cover_images->thumbnails.push_back(std::move(*c_1920x960));
        }
    }

    user.profile_pictures = get_profile_pictures(j.at("profile_img"));

    if (j.contains("user_webpage")) {
        std::string user_webpage = j.at("user_webpage").get<std::string>();
        if (!user_webpage.empty()) {
            user.links.push_back({"Webpage", std::move(user_webpage)});
        }
    }
    auto add_social_as_needed = [&](const char* key, const char* public_name) {
        nlohmann::json social = j["social"];
        if (!social.contains(key)) {
            return;
        }

        std::string url = social[key].at("url").get<std::string>();
        user.links.push_back({public_name, std::move(url)});
    };
    if (j.contains("social") && j["social"].is_object()) {
        add_social_as_needed("twitter", "Twitter");
        add_social_as_needed("instagram", "Instagram");
        add_social_as_needed("tumblr", "Tumblr");
        add_social_as_needed("facebook", "Facebook");
        add_social_as_needed("circlems", "Circle.ms");
        add_social_as_needed("pawoo", "Pawoo");
    }

    blankie::murl::Url ogp_image = j.at("meta").at("ogp").at("image").get<std::string>();
    if (ogp_image.is_host_equal("embed.pixiv.net")) {
        user.ogp_image = "https://embed.pixiv.net/user_profile.php?id="s + std::to_string(user.user_id);
    }
}

void from_json(const nlohmann::json& j, Tag& tag) {
    j.at("tag").get_to(tag.japanese);
    if (j.contains("translation")) {
        tag.english = j["translation"].get<std::string>();
    }
}

void from_json(const nlohmann::json& j, Illust& illust) {
    bool full_data = j.contains("illust_details");
    const nlohmann::json& author_details = j.at("author_details");
    const nlohmann::json& illust_details = full_data ? j.at("illust_details") : j;
    std::optional<nlohmann::json> images_metadata = illust_details.contains("illust_images")
        ? std::optional(illust_details["illust_images"])
        : std::nullopt;

    author_details.at("user_account").get_to(illust.username);
    author_details.at("user_name").get_to(illust.user_display_name);
    illust.user_id = to_ull(author_details.at("user_id").get_ref<const nlohmann::json::string_t&>());
    if (full_data) {
        illust.user_profile_pictures = get_profile_pictures(author_details.at("profile_img"));
    }

    illust.illust_id = to_ull(illust_details.at("id").get_ref<const nlohmann::json::string_t&>());
    illust_details.at("title").get_to(illust.title);
    illust.ai_generated = illust_details.at("ai_type").get<int>() == 2;
    illust_details.at("upload_timestamp").get_to(illust.upload_time);

    if (full_data) {
        if (illust_details.contains("comment_html") && illust_details["comment_html"].is_string()) {
            illust.comment_html = illust_details["comment_html"].get<std::string>();
        }
        illust_details.at("display_tags").get_to(illust.tags);
    }

    if (illust_details.contains("manga_a")) {
        const nlohmann::json& manga_a = illust_details["manga_a"];
        illust.images.reserve(manga_a.size());

        for (size_t i = 0; i < manga_a.size(); i++) {
            illust.images.push_back(get_illust_images(manga_a[i], images_metadata ? std::optional(images_metadata->at(i)) : std::nullopt));
        }
    } else {
        illust.images = {get_illust_images(illust_details, images_metadata ? std::optional(images_metadata->at(0)) : std::nullopt)};
    }
    illust.page_count = to_ull(illust_details.at("page_count").get_ref<const nlohmann::json::string_t&>());
}

void from_json(const nlohmann::json& j, Illusts& illusts) {
    j.at("illusts").get_to(illusts.illusts);
    j.at("total").get_to(illusts.total_illusts);
    j.at("lastPage").get_to(illusts.total_pages);
}

void from_json(const nlohmann::json& j, SearchResults& search_results) {
    const nlohmann::json& tag_translations = j.at("tagTranslation");
    auto get_translated_tag = [&](const std::string& japanese) -> std::optional<std::string> {
        if (!tag_translations.is_object() || !tag_translations.contains(japanese)) {
            return std::nullopt;
        }
        const nlohmann::json& tag = tag_translations[japanese];
        return tag.contains("en")
            ? std::optional(tag["en"].get<std::string>())
            : std::nullopt;
    };

    const nlohmann::json& illusts = j.at("illust").at("data");
    search_results.illusts.illusts.reserve(illusts.size());
    for (const nlohmann::json& i : illusts) {
        const nlohmann::json& i_tags = i.at("tags");
        std::vector<Tag> tags;
        tags.reserve(i_tags.size());

        for (const nlohmann::json& tag : i_tags) {
            std::string japanese = tag.get<std::string>();
            tags.push_back({japanese, get_translated_tag(std::move(japanese))});
        }

        Illust illust = {
            .username = "",
            .user_display_name = i.at("userName").get<std::string>(),
            .user_id = to_ull(i.at("userId").get<std::string>()),
            .user_profile_pictures = get_profile_pictures(i.at("profileImageUrl").get<std::string>()),

            .illust_id = to_ull(i.at("id").get<std::string>()),
            .title = i.at("title").get<std::string>(),
            .ai_generated = i.at("aiType").get<int>() == 2,
            // pixiv does have a createDate field, but it can't be portably parsed by strptime
            // and i cba to use regex for it, especially when it's not even used in this context
            .upload_time = -1,

            .comment_html = std::nullopt,
            .tags = std::move(tags),
            .images = {get_illust_images(i, std::nullopt)},
            .page_count = i.at("pageCount").get<size_t>()
        };
        search_results.illusts.illusts.push_back(illust);
    }

    j.at("illust").at("total").get_to(search_results.illusts.total_illusts);
    search_results.illusts.total_pages = search_results.illusts.total_illusts / 60;
    if (search_results.illusts.total_illusts % 60 != 0) {
        search_results.illusts.total_pages++;
    }
    if (search_results.illusts.total_pages > 10) {
        search_results.illusts.total_pages = 10;
    }

    search_results.tag_translations.reserve(tag_translations.size());
    for (auto &[key, val] : tag_translations.items()) {
        std::optional<std::string> translated_tag = get_translated_tag(key);
        if (translated_tag) {
            search_results.tag_translations.insert({std::move(key), std::move(*translated_tag)});
        }
    }
}

void from_json(const nlohmann::json& j, SearchSuggestion& search_suggestion) {
    j.at("tag_name").get_to(search_suggestion.tag);
    if (j.at("type").get_ref<const nlohmann::json::string_t&>() == "tag_translation") {
        search_suggestion.english_tag = j.at("tag_translation").get<std::string>();
    }
}

static std::regex resolution_path_regex("/c/(\\d+x\\d+)(.+)");
static inline std::optional<std::string> get_1920x960_cover_image(blankie::murl::Url url) {
    std::smatch sm;
    if (!std::regex_match(url.path, sm, resolution_path_regex)) {
        return std::nullopt;
    }
    if (sm[1] == "1920x960") {
        return std::nullopt;
    }
    url.path = "/c/1920x960" + sm.str(2);
    return url.to_string();
}

static std::regex thumbnail_path_regex("/c/[^/]+(/.+)_master\\d+(\\.\\w{3,4})?");
static inline std::optional<std::string> get_original_cover_image(blankie::murl::Url url, const nlohmann::json& cover_image) {
    std::smatch sm;
    if (!std::regex_match(url.path, sm, thumbnail_path_regex)) {
        return std::nullopt;
    }

    url.path = sm.str(1);
    if (cover_image.contains("profile_cover_ext") && cover_image["profile_cover_ext"].is_string()
            && !cover_image["profile_cover_ext"].get_ref<const nlohmann::json::string_t&>().empty()) {
        url.path += '.';
        url.path += cover_image["profile_cover_ext"].get<std::string>();
    } else {
        url.path += sm.str(2);
    }
    return url.to_string();
}

static std::regex profile_picture_thumbnail_path_regex("(/.+)_\\d{2,}(\\.\\w{3,4})");
static inline std::optional<std::string> get_original_profile_picture(blankie::murl::Url url) {
    std::smatch sm;
    if (!std::regex_match(url.path, sm, profile_picture_thumbnail_path_regex)) {
        return std::nullopt;
    }
    url.path = sm.str(1) + sm.str(2);
    return url.to_string();
}

static Images get_profile_pictures(const nlohmann::json& j) {
    Images images;

    if (j.contains("main_s")) {
        images.thumbnails.push_back(j["main_s"].get<std::string>());
    }
    images.thumbnails.push_back(j.at("main").get<std::string>());
    images.original = get_original_profile_picture(images.thumbnails.back().url);

    return images;
}

static Images get_profile_pictures(const std::string& url) {
    return {
        .original = get_original_profile_picture(url),
        .thumbnails = {url}
    };
}

static std::regex illust_360x360_thumbnail_path_regex(
    "(?:/c/[^/]+?/img-master|/img-original)?"
    "(/img/.*/\\d+_p\\d+)(?:_master1200|_square1200)?\\.\\w{3,4}"
);
static inline std::optional<std::string> get_360x360_illust_thumbnail(blankie::murl::Url url) {
    using namespace std::string_literals;

    std::smatch sm;
    if (!std::regex_match(url.path, sm, illust_360x360_thumbnail_path_regex)) {
        return std::nullopt;
    }
    url.path = "/c/360x360_10_webp/img-master"s + sm.str(1) + "_square1200.jpg";
    return url.to_string();
}

static std::regex illust_original_image_path_regex("/c/.+?/(img/.+)(?:_master1200|square1200)\\.\\w{3,4}");
static inline std::optional<std::string> get_original_illust_image(blankie::murl::Url url) {
    using namespace std::string_literals;

    std::smatch sm;
    if (!std::regex_match(url.path, sm, illust_original_image_path_regex)) {
        return std::nullopt;
    }
    url.path = "/img-original/"s + sm.str(1);
    url.fragment = "guess_extension";
    return url.to_string();
}

static std::regex illust_size_regex(
    "/c/(\\d+)x(\\d+)[/_].+"
);
static std::optional<std::pair<uint64_t, uint64_t>> get_thumbnail_size(blankie::murl::Url thumbnail_url, std::optional<std::pair<uint64_t, uint64_t>> original_size) {
    if (!original_size) {
        return std::nullopt;
    }

    uint64_t thumbnail_width, thumbnail_height;

    if (thumbnail_url.path.starts_with("/img-master/")) {
        if (original_size->first <= 1200 && original_size->second <= 1200) {
            return original_size;
        }

        // one side is implicitly 1200
        if (original_size->first >= original_size->second) {
            // original width >= original height

            thumbnail_width = 1200;
            // derived from original_size->second / (original_size->first / thumbnail_width)
            // to make it more accurate without using floats
            thumbnail_height = original_size->second * thumbnail_width / original_size->first;
        } else {
            // original width < original height

            thumbnail_height = 1200;
            // derived from original_size->first / (original_size->second / thumbnail_height)
            // to make it more accurate without using floats
            thumbnail_width = original_size->first * thumbnail_height / original_size->second;
        }
    } else {
        std::smatch sm;
        if (!std::regex_match(thumbnail_url.path, sm, illust_size_regex)) {
            return std::nullopt;
        }

        thumbnail_width = to_ull(sm.str(1));
        // thumbnail_height = to_ull(sm.str(2));

        // derived from original_size->second / (original_size->first / thumbnail_width)
        // to make it more accurate without using floats
        thumbnail_height = original_size->second * thumbnail_width / original_size->first;
    }

    std::pair<uint64_t, uint64_t> thumbnail_size = {thumbnail_width, thumbnail_height};
    return thumbnail_size;
}

static Images get_illust_images(const nlohmann::json& image, std::optional<nlohmann::json> image_metadata) {
    Images images;
    ssize_t add_360x360_to = -1;
    std::optional<std::pair<uint64_t, uint64_t>> original_size;

    if (image_metadata) {
        original_size = {
            to_ull(image_metadata->at("illust_image_width").get_ref<const nlohmann::json::string_t&>()),
            to_ull(image_metadata->at("illust_image_height").get_ref<const nlohmann::json::string_t&>())
        };
    }

    auto add_if_exists = [&](const char* key) {
        if (!image.contains(key) || !image[key].is_string()) {
            return false;
        }
        std::string url = image[key].get<std::string>();
        images.thumbnails.push_back({url, get_thumbnail_size(url, original_size)});
        return true;
    };
    add_if_exists("url_ss");
    add_if_exists("url_placeholder");
    add_if_exists("url_small");
    if (!add_if_exists("url_s")) {
        add_360x360_to = static_cast<ssize_t>(images.thumbnails.size());
    }
    add_if_exists("url");
    if (image.contains("url_big") && image["url_big"].is_string()) {
        images.original = {image["url_big"].get<std::string>(), original_size};
    } else {
        std::optional<std::string> original_url = get_original_illust_image(images.thumbnail_or_original().url);
        if (original_url) {
            images.original = {std::move(*original_url), original_size};
        }
    }

    if (add_360x360_to >= 0) {
        std::optional<std::string> c_360x360 = get_360x360_illust_thumbnail(images.original_or_thumbnail().url);
        if (c_360x360) {
            images.thumbnails.insert(images.thumbnails.begin() + add_360x360_to, {*c_360x360, get_thumbnail_size(*c_360x360, original_size)});
        }
    }

    return images;
}