import { UUID } from "https://deno.land/x/web_bson@v0.3.0/mod.js";

import { auth, body, headers, jwt, page, rest, schema } from "../server/decorators.ts";
import { JWTPayload } from "../utils/JWT.ts";
import AppRouter from "./AppRouter.ts";
import HttpError from "../server/HttpError.ts";
import Image, { Visibility } from "../models/Image.ts";
import { Headers } from "../server/RestRequest.ts";
import { convert } from "../server/decorators/schema.ts";
import { now } from "../utils/utils.ts";
import AppDatabase from "../AppDatabase.ts";
import RestResponse from "../server/RestResponse.ts";
import { Page } from "../server/decorators/page.ts";

export default class ImageRouter extends AppRouter {
    public static deserialize(image: Image, me?: string) {
        return {
            author: image.author,
            created: image.created,
            name: image.name,
            visibility: image.visibility,
            id: image._id,
            file: image.file,
            likes: image.likes?.length ?? 0,
            liked: image.likes?.includes(me!) ?? false,
        };
    }

    @rest('GET', '/')
    async get(@schema('uuid') id: UUID, @jwt('salt', false) @auth() jwt?: JWTPayload) {
        const image = await this.db.images.findOne({ _id: new UUID(id) });

        if (
            !image ||
            image.visibility === Visibility.Private && image.author !== jwt?.name
        ) throw new HttpError("Image doesn't exist.");

        return ImageRouter.deserialize(image, jwt?.name);
    }
    @rest('GET', '/img/:id')
    async file(id: string, @jwt('salt', false) @auth() jwt?: JWTPayload) {
        try {
            const start = await Deno.realPath("images");
            const file = await Deno.realPath(`images/${id}`);
            if (!file.startsWith(start)) throw new HttpError("What the fuck are you doing?", 418);
        }
        catch (e) {
            if (!(e instanceof HttpError)) throw new HttpError("File doesn't exist.", 404);
        }

        const img = await this.db.images.findOne({ _id: new UUID(id.split('.')[0]) }).catch(() => undefined);
        if (img?.visibility === Visibility.Private && img.author !== jwt?.name) throw new HttpError("File doesn't exist.", 404);
        return new RestResponse()
            .body((await Deno.open(`images/${id}`)).readable)
            .contentType(id.split('.')[1]);
    }
    @rest('GET')
    async feed(@page() page: Page, @jwt('salt', false) @auth() jwt?: JWTPayload) {
        const res = await page.apply(this.db.images.find({ visibility: Visibility.Public })).sort({ created: -1 }).toArray();
        if (!res) throw new HttpError('User not found.');
        return res.map(v => ImageRouter.deserialize(v, jwt?.name));
    }
    @rest('GET', '/feed/:username')
    async userFeed(username: string, @page() page: Page, @jwt('salt', false) @auth() jwt?: JWTPayload) {
        const user = await this.db.users.findOne({ username });
        if (user === undefined) throw new HttpError("User not found.");

        let cursor;
        if (user.username === jwt?.name) cursor = this.db.images.find({ _id: { $in: user.images } });
        else cursor = this.db.images.find({ _id: { $in: user.images }, visibility: Visibility.Public });

        return (await page.apply(cursor.sort({ created: -1 })).toArray()).map(v => ImageRouter.deserialize(v, jwt?.name));
    }
    @rest('GET', '/likes/:username')
    async likeFeed(username: string, @page() page: Page, @jwt('salt', false) @auth() jwt?: JWTPayload) {
        const user = await this.db.users.findOne({ username });
        if (user === undefined) throw new HttpError("User not found.");

        const cursor = this.db.images.find({ $or: [
            { _id: { $in: user.likes }, visibility: Visibility.Public, },
            { _id: { $in: user.likes }, author: user.username, }
        ] });

        return (await page.apply(cursor.sort({ created: -1 })).toArray()).map(v => ImageRouter.deserialize(v, jwt?.name));
    }

    @rest('POST', '/upload')
    async upload(@body() body: Blob, @headers() headers: Headers, @jwt(v => v.salt, true) @auth() jwt: JWTPayload) {
        const user = await this.db.users.findOne({ username: jwt.name });
        if (!user) throw new HttpError("You don't exist.");

        // Parse body
        const contentType = headers['content-type'] + "";
        if (!contentType.startsWith('multipart/form-data')) {
            throw new HttpError("Expected a 'Content-type: multipart/form-data; ...' header.");
        }
        const data = await new Request('http://127.0.0.1', {
            body, headers: [ ['content-type', contentType ] ],
            method: 'post'
        }).formData();

        // Clean up data
        if (!data.has('file')) throw new HttpError("Expected a 'file' entry in form data.");
        if (!data.has('body')) throw new HttpError("Expected a 'body' entry in form data.");

        let rawFile: File = data.get('file') as File;
        let rawReq: string = data.get('body') as string;

        if (typeof rawFile === 'string') rawFile = new File([rawFile], 'unknown');
        if (typeof rawReq !== 'string') rawReq = await (rawReq as Blob).text();
        if (rawFile.size > (1 << 20) * 2) throw new HttpError("File too large (max 2MB).");

        // Extract (and check) extension
        const pointI = rawFile.name.lastIndexOf(".");
        if (pointI < 0) throw new HttpError("Given file has no extension.");
        const ext = rawFile.name.substring(pointI + 1).trim();
        if (ext === "") throw new HttpError("Given file has no extension.");

        // Clean up request
        const req = await convert(rawReq, { name: 'string?', visibility: 'number?' });
        req.name ??= rawFile.name;
        req.visibility ??= 0;
        if (req.visibility < 0 || req.visibility > 2) throw new HttpError("body.visibility: Must be 0, 1, or 2");
        const id = new UUID();
        // Create file
        const img: Image = {
            _id: id,
            author: user.username,
            created: now(),
            name: req.name!,
            visibility: req.visibility,
            file: `${id}.${ext}`,
            likes: [],
        };
        await Deno.mkdir('images', { recursive: true });
        const out = await Deno.open(`images/${id}.${ext}`, { write: true, create: true });

        for await (const bit of rawFile.stream()) out.write(bit);
        out.close();

        // Write to DB
        try {
            await this.db.images.insertOne(img);
            await this.db.users.updateOne({ username: user.username }, { $push: { images: id } });
            return ImageRouter.deserialize(img);
        }
        catch (e) {
            await Deno.remove(`images/${id}.${ext}`);
            throw e;
        }
    }
    @rest('POST', '/change')
    async change(@schema('uuid') id: UUID, @body() raw: unknown, @jwt(v => v.salt, true) @auth() jwt: JWTPayload) {
        const body = await convert(raw, { name: 'string?', visibility: 'number?' });
        const user = await this.db.users.findOne({ username: jwt.name });
        if (!user) throw new HttpError("You don't exist.");

        const img = await this.db.images.findOne({ _id: id });
        if (!img) throw new HttpError("Image doesn't exist.");
        if (user.username !== img.author) throw new HttpError("You don't own the image.");

        await this.db.images.updateOne({ _id: id }, { $set: { name: body.name, visibility: body.visibility } });
        return ImageRouter.deserialize(img);
    }
    @rest('POST', '/delete')
    async delete(@schema('uuid') id: UUID, @jwt(v => v.salt, true) @auth() jwt: JWTPayload) {
        const user = await this.db.users.findOne({ username: jwt.name });
        if (!user) throw new HttpError("You don't exist.");

        const img = await this.db.images.findOne({ _id: id });
        if (!img) throw new HttpError("Image doesn't exist.");
        if (user.username !== img.author) throw new HttpError("You don't own the image.");

        await this.db.images.deleteOne({ _id: id });
        await this.db.users.updateMany({}, {
            $pull: { images: id, likes: id }
        });
        return ImageRouter.deserialize(img);
    }

    @rest('POST', '/like')
    async like(@schema('uuid') id: UUID, @jwt(v => v.salt, true) @auth() jwt: JWTPayload) {
        const user = await this.db.users.findOne({ username: jwt.name });
        if (!user) throw new HttpError("You don't exist.");

        const res = await this.db.images.updateOne(
            { _id: id, visibility: { $not: { $eq: Visibility.Private } } },
            { $addToSet: { likes: jwt.name } }
        );
        if (res.matchedCount === 0) throw new HttpError("Image doesn't exist.");
        await this.db.users.updateOne(
            { username: jwt.name },
            { $addToSet: { likes: id } }
        );


        return ImageRouter.deserialize((await this.db.images.findOne({ _id: id }))!, jwt?.name);
    }
    @rest('POST', '/unlike')
    async unlike(@schema('uuid') id: UUID, @jwt(v => v.salt, true) @auth() jwt: JWTPayload) {
        const user = await this.db.users.findOne({ username: jwt.name });
        if (!user) throw new HttpError("You don't exist.");

        const res = await this.db.images.updateOne(
            { _id: id, visibility: { $not: { $eq: Visibility.Private } } },
            { $pull: { likes: jwt.name } }
        );
        if (res.matchedCount === 0) throw new HttpError("Image doesn't exist.");
        await this.db.users.updateOne(
            { username: jwt.name },
            { $pull: { likes: id } }
        );

        return ImageRouter.deserialize((await this.db.images.findOne({ _id: id }))!);
    }

    public constructor(private db: AppDatabase) {
        super();
        db.images.createIndexes({ indexes: [ { key: { created: -1 }, name: 'Image Order' } ] });
    }
}