import {
    BadRequestException,
    ForbiddenException,
    Injectable,
    NotFoundException,
} from "@nestjs/common";
import { ConfigService } from "@nestjs/config";
import { JwtService } from "@nestjs/jwt";
import { Share, User } from "@prisma/client";
import * as archiver from "archiver";
import * as argon from "argon2";
import * as fs from "fs";
import * as moment from "moment";
import { FileService } from "src/file/file.service";
import { PrismaService } from "src/prisma/prisma.service";
import { CreateShareDTO } from "./dto/createShare.dto";

@Injectable()
export class ShareService {
    constructor(
        private prisma: PrismaService,
        private fileService: FileService,
        private config: ConfigService,
        private jwtService: JwtService
    ) {
    }

    async create(share: CreateShareDTO, user: User) {
        if (!(await this.isShareIdAvailable(share.id)).isAvailable)
            throw new BadRequestException("Share id already in use");

        if (!share.security || Object.keys(share.security).length == 0)
            share.security = undefined;

        if (share.security?.password) {
            share.security.password = await argon.hash(share.security.password);
        }

        // We have to add an exception for "never" (since moment won't like that)
        let expirationDate;
        if (share.expiration !== "never") {
            expirationDate = moment()
                .add(
                    share.expiration.split("-")[0],
                    share.expiration.split("-")[1] as moment.unitOfTime.DurationConstructor
                )
                .toDate();

            // Throw error if expiration date is now
            if (expirationDate.setMilliseconds(0) == new Date().setMilliseconds(0))
                throw new BadRequestException("Invalid expiration date");
        } else {
            expirationDate = moment(0).toDate();
        }

        return await this.prisma.share.create({
            data: {
                ...share,
                expiration: expirationDate,
                creator: {connect: {id: user.id}},
                security: {create: share.security},
            },
        });
    }

    async createZip(shareId: string) {
        const path = `./data/uploads/shares/${shareId}`;

        const files = await this.prisma.file.findMany({where: {shareId}});
        const archive = archiver("zip", {
            zlib: {level: 9},
        });
        const writeStream = fs.createWriteStream(`${path}/archive.zip`);

        for (const file of files) {
            archive.append(fs.createReadStream(`${path}/${file.id}`), {
                name: file.name,
            });
        }

        archive.pipe(writeStream);
        await archive.finalize();
    }

    async complete(id: string) {
        const moreThanOneFileInShare =
            (await this.prisma.file.findMany({where: {shareId: id}})).length != 0;

        if (!moreThanOneFileInShare)
            throw new BadRequestException(
                "You need at least on file in your share to complete it."
            );

        this.createZip(id).then(() =>
            this.prisma.share.update({where: {id}, data: {isZipReady: true}})
        );

        return await this.prisma.share.update({
            where: {id},
            data: {uploadLocked: true},
        });
    }

    async getSharesByUser(userId: string) {
        return await this.prisma.share.findMany({
            where: {
                creator: {id: userId},
                // We want to grab any shares that are not expired or have their expiration date set to "never" (unix 0)
                OR: [{expiration: {gt: new Date()}}, {expiration: {equals: moment(0).toDate()}}]
            },
        });
    }

    async get(id: string) {
        let share: any = await this.prisma.share.findUnique({
            where: {id},
            include: {
                files: true,
                creator: true,
            },
        });

        if (!share || !share.uploadLocked)
            throw new NotFoundException("Share not found");

        share.files = share.files.map((file) => {
            file["url"] = `http://localhost:8080/file/${file.id}`;
            return file;
        });

        await this.increaseViewCount(share);

        return share;
    }

    async getMetaData(id: string) {
        const share = await this.prisma.share.findUnique({
            where: {id},
        });

        if (!share || !share.uploadLocked)
            throw new NotFoundException("Share not found");

        return share;
    }

    async remove(shareId: string) {
        const share = await this.prisma.share.findUnique({
            where: {id: shareId},
        });

        if (!share) throw new NotFoundException("Share not found");

        await this.fileService.deleteAllFiles(shareId);
        await this.prisma.share.delete({where: {id: shareId}});
    }

    async isShareCompleted(id: string) {
        return (await this.prisma.share.findUnique({where: {id}})).uploadLocked;
    }

    async isShareIdAvailable(id: string) {
        const share = await this.prisma.share.findUnique({where: {id}});
        return {isAvailable: !share};
    }

    async increaseViewCount(share: Share) {
        await this.prisma.share.update({
            where: {id: share.id},
            data: {views: share.views + 1},
        });
    }

    async exchangeSharePasswordWithToken(shareId: string, password: string) {
        const sharePassword = (
            await this.prisma.shareSecurity.findFirst({
                where: {share: {id: shareId}},
            })
        ).password;

        if (!(await argon.verify(sharePassword, password)))
            throw new ForbiddenException("Wrong password");

        const token = this.generateShareToken(shareId);
        return {token};
    }

    generateShareToken(shareId: string) {
        return this.jwtService.sign(
            {
                shareId,
            },
            {
                expiresIn: "1h",
                secret: this.config.get("JWT_SECRET"),
            }
        );
    }

    verifyShareToken(shareId: string, token: string) {
        try {
            const claims = this.jwtService.verify(token, {
                secret: this.config.get("JWT_SECRET"),
            });

            return claims.shareId == shareId;
        } catch {
            return false;
        }
    }
}