import { Body, FormField, Path, Post, Put, Request, Response, Route, Security, SuccessResponse, Tags, UploadedFile, UploadedFiles } from 'tsoa';
import { ValidationError } from '../middleware/errorHandler';
import { ChaptersLessonService } from '../services/ChaptersLesson.service';
import { MultiLanguageText } from '../types/index';
import { UploadedFileInfo, CreateLessonInput, CreateLessonResponse, UpdateLessonResponse } from '../types/ChaptersLesson.typs';

const chaptersLessonService = new ChaptersLessonService();

@Route('api/instructors/courses/{courseId}/chapters/{chapterId}/lessons')
@Tags('Lessons - File Upload')
export class LessonsController {

    /**
     * สร้างบทเรียนใหม่พร้อมไฟล์แนบ
     * Create a new lesson with optional video and attachments
     * 
     * @param courseId Course ID
     * @param chapterId Chapter ID
     * @param title ชื่อบทเรียน (JSON string: { th: "", en: "" })
     * @param type ประเภทบทเรียน (VIDEO | QUIZ)
     * @param content เนื้อหาบทเรียน (JSON string: { th: "", en: "" })
     * @param sort_order ลำดับการแสดงผล
     * @param video ไฟล์วิดีโอ (สำหรับ type=VIDEO เท่านั้น)
     * @param attachments ไฟล์แนบ (PDFs, เอกสาร, รูปภาพ)
     */
    @Post('upload')
    @Security('jwt', ['instructor'])
    @SuccessResponse('201', 'Lesson created successfully')
    @Response('400', 'Validation error')
    @Response('401', 'Unauthorized')
    @Response('403', 'Forbidden')
    public async createLessonWithFiles(
        @Request() request: any,
        @Path() courseId: number,
        @Path() chapterId: number,
        @FormField() title: string,
        @FormField() type: 'VIDEO' | 'QUIZ',
        @FormField() content?: string,
        @FormField() sort_order?: string,
        @UploadedFile() video?: Express.Multer.File,
        @UploadedFiles() attachments?: Express.Multer.File[]
    ): Promise<CreateLessonResponse> {
        const token = request.headers.authorization?.replace('Bearer ', '');
        if (!token) throw new ValidationError('No token provided');

        // Parse JSON fields
        const parsedTitle: MultiLanguageText = JSON.parse(title);
        const parsedContent = content ? JSON.parse(content) : undefined;
        const sortOrder = sort_order ? parseInt(sort_order, 10) : undefined;

        if (!parsedTitle.th || !parsedTitle.en) {
            throw new ValidationError('Title must have both Thai (th) and English (en) values');
        }

        // Transform files to UploadedFileInfo
        let videoInfo: UploadedFileInfo | undefined;
        let attachmentsInfo: UploadedFileInfo[] | undefined;

        if (video) {
            videoInfo = {
                originalname: video.originalname,
                mimetype: video.mimetype,
                size: video.size,
                buffer: video.buffer,
            };
        }

        if (attachments && attachments.length > 0) {
            attachmentsInfo = attachments.map(file => ({
                originalname: file.originalname,
                mimetype: file.mimetype,
                size: file.size,
                buffer: file.buffer,
            }));
        }

        const input: CreateLessonInput = {
            token,
            course_id: courseId,
            chapter_id: chapterId,
            title: parsedTitle,
            content: parsedContent,
            type,
            sort_order: sortOrder,
            video: videoInfo,
            attachments: attachmentsInfo,
        };

        return await chaptersLessonService.createLesson(input);
    }

    /**
     * เพิ่มวิดีโอและไฟล์แนบให้บทเรียน VIDEO ที่มีอยู่แล้ว
     * Add video and attachments to an existing VIDEO type lesson
     * 
     * @param courseId Course ID
     * @param chapterId Chapter ID
     * @param lessonId Lesson ID
     * @param video ไฟล์วิดีโอ (required)
     * @param attachments ไฟล์แนบ
     */
    @Post('{lessonId}/video')
    @Security('jwt', ['instructor'])
    @SuccessResponse('200', 'Video added successfully')
    @Response('400', 'Validation error')
    @Response('401', 'Unauthorized')
    @Response('403', 'Forbidden')
    @Response('404', 'Lesson not found')
    public async addVideoToLesson(
        @Request() request: any,
        @Path() courseId: number,
        @Path() chapterId: number,
        @Path() lessonId: number,
        @UploadedFile() video: Express.Multer.File,
        @UploadedFiles() attachments?: Express.Multer.File[]
    ): Promise<CreateLessonResponse> {
        const token = request.headers.authorization?.replace('Bearer ', '');
        if (!token) throw new ValidationError('No token provided');

        if (!video) {
            throw new ValidationError('Video file is required');
        }

        // Transform files to UploadedFileInfo
        const videoInfo: UploadedFileInfo = {
            originalname: video.originalname,
            mimetype: video.mimetype,
            size: video.size,
            buffer: video.buffer,
        };

        let attachmentsInfo: UploadedFileInfo[] | undefined;
        if (attachments && attachments.length > 0) {
            attachmentsInfo = attachments.map(file => ({
                originalname: file.originalname,
                mimetype: file.mimetype,
                size: file.size,
                buffer: file.buffer,
            }));
        }

        return await chaptersLessonService.addVideoLesson({
            token,
            course_id: courseId,
            lesson_id: lessonId,
            video: videoInfo,
            attachments: attachmentsInfo,
        });
    }

    /**
     * อัปเดตวิดีโอและไฟล์แนบของบทเรียน VIDEO
     * Update video and attachments of an existing VIDEO type lesson
     * 
     * @param courseId Course ID
     * @param chapterId Chapter ID
     * @param lessonId Lesson ID
     * @param video ไฟล์วิดีโอใหม่
     * @param attachments ไฟล์แนบใหม่
     */
    @Put('{lessonId}/video')
    @Security('jwt', ['instructor'])
    @SuccessResponse('200', 'Video updated successfully')
    @Response('400', 'Validation error')
    @Response('401', 'Unauthorized')
    @Response('403', 'Forbidden')
    @Response('404', 'Lesson not found')
    public async updateVideoLesson(
        @Request() request: any,
        @Path() courseId: number,
        @Path() chapterId: number,
        @Path() lessonId: number,
        @UploadedFile() video?: Express.Multer.File,
        @UploadedFiles() attachments?: Express.Multer.File[]
    ): Promise<UpdateLessonResponse> {
        const token = request.headers.authorization?.replace('Bearer ', '');
        if (!token) throw new ValidationError('No token provided');

        // Transform files to UploadedFileInfo
        let videoInfo: UploadedFileInfo | undefined;
        let attachmentsInfo: UploadedFileInfo[] | undefined;

        if (video) {
            videoInfo = {
                originalname: video.originalname,
                mimetype: video.mimetype,
                size: video.size,
                buffer: video.buffer,
            };
        }

        if (attachments && attachments.length > 0) {
            attachmentsInfo = attachments.map(file => ({
                originalname: file.originalname,
                mimetype: file.mimetype,
                size: file.size,
                buffer: file.buffer,
            }));
        }

        return await chaptersLessonService.updateVideoLesson({
            token,
            course_id: courseId,
            lesson_id: lessonId,
            video: videoInfo,
            attachments: attachmentsInfo,
        });
    }
}