import { Injectable } from '@nestjs/common';
import { DateTime } from 'luxon';
import {
    GenerateAllTeamsGradingParams,
    GenerateTeamGradingParams,
} from '../markdown/markdown.types';
import {
    FileService,
    GenerateFilenameParams,
    GenerateTutorialFilenameParams,
} from './file.service';
import { AttendancePDFGenerator } from './subservices/PDFGenerator.attendance';
import { CredentialsPDFGenerator } from './subservices/PDFGenerator.credentials';
import { GradingPDFGenerator } from './subservices/PDFGenerator.grading';
import { ScheinResultsPDFGenerator } from './subservices/PDFGenerator.schein';
import { ScheinexamResultPDFGenerator } from './subservices/PDFGenerator.scheinexam';

@Injectable()
export class PdfService {
    constructor(
        private readonly attendancePDF: AttendancePDFGenerator,
        private readonly credentialsPDF: CredentialsPDFGenerator,
        private readonly scheinResultsPDF: ScheinResultsPDFGenerator,
        private readonly scheinexamResultPDF: ScheinexamResultPDFGenerator,
        private readonly gradingsPDF: GradingPDFGenerator,
        private readonly fileService: FileService
    ) {}

    /**
     * Generates a list for signing the attendances of the tutorial at the given date.
     *
     * @param tutorialId ID of the tutorial to generate the PDF for.
     * @param date Date to generate the PDF for.
     *
     * @returns Buffer containing the generated PDF.
     *
     * @throws `NotFoundException` - If no tutorial with the given ID could be found.
     */
    async generateAttendancePDF(tutorialId: string, date: string): Promise<Buffer> {
        return this.attendancePDF.generatePDF({
            tutorialId,
            date: DateTime.fromISO(date),
        });
    }

    /**
     * Generates a list with the credentials for all users.
     *
     * The list only contains the password for users which have not yet changed their password (ie they still have a `temporaryPassword`).
     *
     * @returns Buffer containing the generated PDF.
     */
    async generateCredentialsPDF(): Promise<Buffer> {
        return this.credentialsPDF.generatePDF();
    }

    /**
     * Generates a list with the schein results for all students with matriculation numbers.
     *
     * The list either has shortened matriculation numbers or not, depending on the corresponding parameter.
     *
     * @param enableShortMatriculationNo Flag to determine if the matriculation numbers should be shortened or not.
     *
     * @returns Buffer containing the generated PDF.
     */
    async generateStudentScheinOverviewPDF(enableShortMatriculationNo: boolean): Promise<Buffer> {
        return this.scheinResultsPDF.generatePDF({
            enableShortMatriculationNo,
        });
    }

    /**
     * Generates a list with the scheinexam results for the given scheinexam for all students with matriculation numbers.
     *
     * The list either has shortened matriculation numbers or not, depending on the corresponding parameter.
     *
     * @param id ID of the scheinexam to get the list for.
     * @param enableShortMatriculationNo Flag to determine if the matriculation numbers should be shortened or not.
     *
     * @returns Buffer containing the generated PDF.
     */
    async generateScheinexamResultPDF(
        id: string,
        enableShortMatriculationNo: boolean
    ): Promise<Buffer> {
        return this.scheinexamResultPDF.generatePDF({
            id,
            enableShortMatriculationNo,
        });
    }

    /**
     * Generates a PDF from the grading of the given team for the given sheet.
     *
     * @param params Options passed to the markdown generation function.
     *
     * @returns Buffer or NodeJS.ReadableStream containing the generated PDF.
     *
     * @throws `NotFoundException` - If either no team with the given ID or no sheet with the given ID could be found.
     * @throws `BadRequestException` - If the given team does not have any students or the students do not hold a grading for the given sheet.
     */
    async generateGradingPDF(
        params: GenerateTeamGradingParams
    ): Promise<Buffer | NodeJS.ReadableStream> {
        return this.gradingsPDF.generateTeamGradingFiles(params);
    }

    /**
     * Generates a ZIP containing a PDF per team of the given tutorial with it's grading for the given sheet.
     *
     * @param params Options passed to the markdown generation function.
     *
     * @returns ReadableStream containing the ZIP-file containing the PDFs of the gradings.
     *
     * @throws `NotFoundException` - If either no tutorial with the given ID or no sheet with the given ID could be found.
     */
    async generateTutorialGradingZIP(
        params: GenerateAllTeamsGradingParams
    ): Promise<NodeJS.ReadableStream> {
        return this.gradingsPDF.generateTutorialGradingZIP(params);
    }

    /**
     * Generates a grading filename without an extension.
     *
     * @param dto Params to generate the filename from.
     *
     * @returns Generated filename.
     */
    async generateGradingFilename(params: GenerateFilenameParams): Promise<string> {
        return this.fileService.generateGradingFilename(params);
    }

    /**
     * Generates a filename for a grading zip file containing the gradings of all teams within a tutorial without an extension.
     *
     * @param dto Params to generate the filename from.
     *
     * @returns Generated filename.
     */
    async generateTutorialGradingFilename(params: GenerateTutorialFilenameParams): Promise<string> {
        return this.fileService.generateTutorialGradingFilename(params);
    }
}