#include <utility>

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

static Element generate_pager(const Illusts& illusts, size_t page, bool first_selector);
static inline Element generate_content(const httplib::Request& req, const Config& config, const Illusts& illusts);

void user_illustrations_route(const httplib::Request& req, httplib::Response& res, const Config& config, PixivClient& pixiv_client) {
    uint64_t user_id = to_ull(req.matches[1].str());
    uint64_t page = req.has_param("p") ? to_ull(req.get_param_value("p")) - 1 : 0;
    User user;
    Illusts illusts;

    try {
        user = pixiv_client.get_user(user_id);
        illusts = pixiv_client.get_illusts(user_id, page);
    } catch (const PixivException& e) {
        if (e.status == 404) {
            res.status = 404;
            serve_error(req, res, config, "404: User not found", e.what());
        } else {
            res.status = 500;
            serve_error(req, res, config, "500: Internal server error", "Failed to fetch user information", e.what());
        }
        return;
    } catch (const std::exception& e) {
        res.status = 500;
        serve_error(req, res, config, "500: Internal server error", "Failed to fetch user information", e.what());
        return;
    }

    Element body("body", {
        generate_user_header(std::move(user), config),
        generate_pager(illusts, page, true),
        Element("br"),
        generate_content(req, config, illusts),
        generate_pager(illusts, page, false)
    });
    serve(req, res, config, user.display_name + " illustrations", std::move(body));
}

static Element generate_pager(const Illusts& illusts, size_t page, bool first_selector) {
    auto link = [](size_t new_page, const char* text, bool add_link) {
        using namespace std::string_literals;

        Element b("b");
        std::string href = "?p="s + std::to_string(new_page) + "#pageselector";

        if (add_link) {
            b.nodes.push_back(Element("a", {{"href", std::move(href)}}, {text}));
        } else {
            b.nodes.push_back(text);
        }
        return b;
    };

    Element div("div", {{"class", "center"}}, {
        link(1, "First", page != 0), " ",
        link(page, "Prev", page != 0), " ",
        std::to_string(page + 1), "/", std::to_string(illusts.total_pages), " ",
        link(page + 2, "Next", page + 1 < illusts.total_pages), " ",
        link(illusts.total_pages, "Last", page + 1 < illusts.total_pages)
    });
    if (first_selector) {
        div.attributes.push_back({"id", "pageselector"});
    }
    return div;
}

static inline Element generate_content(const httplib::Request& req, const Config& config, const Illusts& illusts) {
    Element div("div", {{"class", "userillustrations"}}, {});

    div.nodes.reserve(illusts.illusts.size());
    for (const Illust& i : illusts.illusts) {
        std::string illust_url = get_origin(req, config) + "/artworks/" + std::to_string(i.illust_id);
        std::string image_url = proxy_image_url(config, i.images[0].thumbnail_or_original());

        div.nodes.push_back(Element("a", {{"href", {std::move(illust_url)}}}, {
            Element("img", {{"loading", "lazy"}, {"src", std::move(image_url)}}, {}),
            Element("p", {i.title})
        }));
    }

    return div;
}