const { queryOne, queryAll } = require('../shared/database');
const { getAllExtensions } = require('../shared/extensions');

async function getBookById(id) {
    const row = await queryOne("SELECT full_data FROM books WHERE id = ?", [id]);

    if (row) {
        return JSON.parse(row.full_data);
    }

    try {
        console.log(`[Book] Local miss for ID ${id}, fetching live...`);
        const query = `
        query ($id: Int) {
            Media(id: $id, type: MANGA) {
                id idMal title { romaji english native userPreferred } type format status description
                startDate { year month day } endDate { year month day } season seasonYear seasonInt
                episodes duration chapters volumes countryOfOrigin isLicensed source hashtag
                trailer { id site thumbnail } updatedAt coverImage { extraLarge large medium color }
                bannerImage genres synonyms averageScore meanScore popularity isLocked trending favourites
                tags { id name description category rank isGeneralSpoiler isMediaSpoiler isAdult userId }
                relations { edges { relationType node { id title { romaji } } } }
                characters(page: 1, perPage: 10) { nodes { id name { full } } }
                studios { nodes { id name isAnimationStudio } }
                isAdult nextAiringEpisode { airingAt timeUntilAiring episode }
                externalLinks { url site } 
                rankings { id rank type format year season allTime context }
            }
        }`;

        const response = await fetch('https://graphql.anilist.co', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json', 'Accept': 'application/json' },
            body: JSON.stringify({ query, variables: { id: parseInt(id) } })
        });

        const data = await response.json();
        if (data.data && data.data.Media) {
            return data.data.Media;
        }
    } catch(e) {
        console.error("Fetch error:", e);
    }

    return { error: "Book not found" };
}

async function getTrendingBooks() {
    const rows = await queryAll("SELECT full_data FROM trending_books ORDER BY rank ASC LIMIT 10");
    return rows.map(r => JSON.parse(r.full_data));
}

async function getPopularBooks() {
    const rows = await queryAll("SELECT full_data FROM popular_books ORDER BY rank ASC LIMIT 10");
    return rows.map(r => JSON.parse(r.full_data));
}

async function searchBooksLocal(query) {
    if (!query || query.length < 2) {
        return [];
    }

    const sql = `SELECT full_data FROM books WHERE full_data LIKE ? LIMIT 50`;
    const rows = await queryAll(sql, [`%${query}%`]);

    const results = rows.map(row => JSON.parse(row.full_data));

    const clean = results.filter(book => {
        const searchTerms = [
            book.title.english,
            book.title.romaji,
            book.title.native,
            ...(book.synonyms || [])
        ].filter(Boolean).map(t => t.toLowerCase());

        return searchTerms.some(term => term.includes(query.toLowerCase()));
    });

    return clean.slice(0, 10);
}

async function searchBooksAniList(query) {
    const gql = `
    query ($search: String) {
        Page(page: 1, perPage: 5) {
            media(search: $search, type: MANGA, isAdult: false) {
                id title { romaji english native } 
                coverImage { extraLarge large } 
                bannerImage description averageScore format 
                seasonYear startDate { year }
            }
        }
    }`;

    const response = await fetch('https://graphql.anilist.co', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json', 'Accept': 'application/json' },
        body: JSON.stringify({ query: gql, variables: { search: query } })
    });

    const liveData = await response.json();

    if (liveData.data && liveData.data.Page.media.length > 0) {
        return liveData.data.Page.media;
    }

    return [];
}

async function searchBooksInExtension(ext, name, query) {
    if (!ext) return [];

    if ((ext.type === 'book-board' || ext.type === 'manga-board') && ext.search) {
        try {
            console.log(`[${name}] Searching for book: ${query}`);
            const matches = await ext.search({
                query: query,
                media: {
                    romajiTitle: query,
                    englishTitle: query,
                    startDate: { year: 0, month: 0, day: 0 }
                }
            });

            if (matches && matches.length > 0) {
                return matches.map(m => ({
                    id: m.id,
                    extensionName: name,
                    title: { romaji: m.title, english: m.title },
                    coverImage: { large: m.image || '' },
                    averageScore: m.rating || m.score || null,
                    format: 'MANGA',
                    seasonYear: null,
                    isExtensionResult: true
                }));
            }
        } catch (e) {
            console.error(`Extension search failed for ${name}:`, e);
        }
    }

    return [];
}

async function searchBooksExtensions(query) {
    const extensions = getAllExtensions();

    for (const [name, ext] of extensions) {
        const results = await searchBooksInExtension(ext, name, query);
        if (results.length > 0) return results;
    }

    return [];
}

async function getChaptersForBook(id) {
    let bookData = null;
    let searchTitle = null;

    if (typeof id === "string" && isNaN(Number(id))) {
        searchTitle = id.replaceAll("-", " ");
    } else {
        bookData = await queryOne("SELECT full_data FROM books WHERE id = ?", [id])
            .then(row => row ? JSON.parse(row.full_data) : null)
            .catch(() => null);

        if (!bookData) {
            try {
                const query = `query ($id: Int) {
                    Media(id: $id, type: MANGA) {
                        title { romaji english }
                        startDate { year month day }
                    }
                }`;

                const res = await fetch('https://graphql.anilist.co', {
                    method: 'POST',
                    headers: { 'Content-Type': 'application/json' },
                    body: JSON.stringify({ query, variables: { id: parseInt(id) } })
                });

                const d = await res.json();
                if (d.data?.Media) bookData = d.data.Media;
            } catch (e) {}
        }

        if (!bookData) return { chapters: [] };

        const titles = [bookData.title.english, bookData.title.romaji].filter(Boolean);
        searchTitle = titles[0];
    }


    const allChapters = [];
    const extensions = getAllExtensions();

    const searchPromises = Array.from(extensions.entries())
        .filter(([_, ext]) =>
            (ext.type === 'book-board' || ext.type === 'manga-board') &&
            ext.search && ext.findChapters
        )
        .map(async ([name, ext]) => {
            try {
                console.log(`[${name}] Searching chapters for: ${searchTitle}`);

                const matches = await ext.search({
                    query: searchTitle,
                    media: bookData ? {
                        romajiTitle: bookData.title.romaji,
                        englishTitle: bookData.title.english,
                        startDate: bookData.startDate
                    } : {}
                });

                if (matches?.length) {
                    const best = matches[0];
                    const chaps = await ext.findChapters(best.id);

                    if (chaps?.length) {
                        console.log(`[${name}] Found ${chaps.length} chapters.`);
                        chaps.forEach(ch => {
                            allChapters.push({
                                id: ch.id,
                                number: parseFloat(ch.number),
                                title: ch.title,
                                date: ch.releaseDate,
                                provider: name
                            });
                        });
                    }
                } else {
                    console.log(`[${name}] No matches found for book.`);
                }
            } catch (e) {
                console.error(`Failed to fetch chapters from ${name}:`, e.message);
            }
        });

    await Promise.all(searchPromises);

    return { chapters: allChapters.sort((a, b) => a.number - b.number) };
}

async function getChapterContent(bookId, chapterIndex, providerName) {
    const extensions = getAllExtensions();
    const ext = extensions.get(providerName);

    if (!ext) {
        throw new Error("Provider not found");
    }

    const chapterList = await getChaptersForBook(bookId);

    if (!chapterList?.chapters || chapterList.chapters.length === 0) {
        throw new Error("Chapters not found");
    }

    const providerChapters = chapterList.chapters.filter(c => c.provider === providerName);
    const index = parseInt(chapterIndex, 10);

    if (Number.isNaN(index)) {
        throw new Error("Invalid chapter index");
    }

    if (!providerChapters[index]) {
        throw new Error("Chapter index out of range");
    }

    const selectedChapter = providerChapters[index];

    const chapterId = selectedChapter.id;
    const chapterTitle = selectedChapter.title || null;
    const chapterNumber = typeof selectedChapter.number === 'number' ? selectedChapter.number : index;

    try {
        if (ext.mediaType === "manga") {
            const pages = await ext.findChapterPages(chapterId);
            return {
                type: "manga",
                chapterId,
                title: chapterTitle,
                number: chapterNumber,
                provider: providerName,
                pages
            };
        }

        if (ext.mediaType === "ln") {
            const content = await ext.findChapterPages(chapterId);
            return {
                type: "ln",
                chapterId,
                title: chapterTitle,
                number: chapterNumber,
                provider: providerName,
                content
            };
        }

        throw new Error("Unknown mediaType");
    } catch (err) {
        console.error(`[Chapter] Error loading from ${providerName}:`, err && err.message ? err.message : err);
        throw err;
    }
}

module.exports = {
    getBookById,
    getTrendingBooks,
    getPopularBooks,
    searchBooksLocal,
    searchBooksAniList,
    searchBooksExtensions,
    searchBooksInExtension,
    getChaptersForBook,
    getChapterContent
};