// Veo Video Service - AI-powered video generation
// Path: src/modules/visual-generation/services/veo-video.service.ts

import { Injectable, Logger } from '@nestjs/common';

export interface VideoGenerationRequest {
    prompt: string;
    duration?: VideoDuration;
    aspectRatio?: VideoAspectRatio;
    style?: VideoStyle;
    motion?: MotionType;
    audio?: AudioOptions;
    platform?: string;
}

export type VideoDuration = '5s' | '10s' | '15s' | '30s' | '60s';

export type VideoAspectRatio = '1:1' | '9:16' | '16:9' | '4:5';

export type VideoStyle =
    | 'cinematic'
    | 'documentary'
    | 'animated'
    | 'motion_graphics'
    | 'time_lapse'
    | 'slow_motion'
    | 'hyperlapse'
    | 'stopmotion'
    | 'vlog'
    | 'corporate';

export type MotionType =
    | 'static'
    | 'pan_left'
    | 'pan_right'
    | 'zoom_in'
    | 'zoom_out'
    | 'dolly_in'
    | 'dolly_out'
    | 'orbit'
    | 'tilt_up'
    | 'tilt_down';

export interface AudioOptions {
    music?: MusicStyle;
    voiceover?: boolean;
    soundEffects?: boolean;
}

export type MusicStyle =
    | 'upbeat'
    | 'calm'
    | 'dramatic'
    | 'corporate'
    | 'inspirational'
    | 'electronic'
    | 'acoustic'
    | 'none';

export interface GeneratedVideo {
    id: string;
    prompt: string;
    url: string;
    thumbnailUrl: string;
    duration: VideoDuration;
    aspectRatio: VideoAspectRatio;
    style: VideoStyle;
    resolution: VideoResolution;
    fps: number;
    fileSize: number; // in bytes
    metadata: VideoMetadata;
    status: VideoStatus;
    createdAt: Date;
}

export interface VideoResolution {
    width: number;
    height: number;
    quality: '720p' | '1080p' | '4k';
}

export interface VideoMetadata {
    model: string;
    generationTime: number;
    frames: number;
    hasAudio: boolean;
    audioTrack?: string;
    tags: string[];
}

export type VideoStatus = 'queued' | 'processing' | 'completed' | 'failed';

export interface VideoScene {
    order: number;
    duration: string;
    prompt: string;
    motion?: MotionType;
    transition?: TransitionType;
}

export type TransitionType =
    | 'cut'
    | 'fade'
    | 'dissolve'
    | 'wipe'
    | 'zoom'
    | 'slide';

@Injectable()
export class VeoVideoService {
    private readonly logger = new Logger(VeoVideoService.name);

    // Platform-specific video defaults
    private readonly platformDefaults: Record<string, {
        duration: VideoDuration;
        aspectRatio: VideoAspectRatio;
        style: VideoStyle;
    }> = {
            tiktok: { duration: '15s', aspectRatio: '9:16', style: 'vlog' },
            instagram_reel: { duration: '15s', aspectRatio: '9:16', style: 'cinematic' },
            instagram_story: { duration: '10s', aspectRatio: '9:16', style: 'motion_graphics' },
            youtube_short: { duration: '30s', aspectRatio: '9:16', style: 'vlog' },
            youtube: { duration: '60s', aspectRatio: '16:9', style: 'cinematic' },
            linkedin: { duration: '30s', aspectRatio: '16:9', style: 'corporate' },
            twitter: { duration: '15s', aspectRatio: '16:9', style: 'motion_graphics' },
        };

    // Style prompt modifiers
    private readonly styleModifiers: Record<VideoStyle, string> = {
        cinematic: 'cinematic quality, film-like, dramatic lighting, professional',
        documentary: 'documentary style, authentic, natural lighting, storytelling',
        animated: 'animated, cartoon style, vibrant colors, fun',
        motion_graphics: 'motion graphics, smooth transitions, modern design, clean',
        time_lapse: 'time-lapse, accelerated motion, passage of time',
        slow_motion: 'slow motion, detailed, dramatic, fluid movement',
        hyperlapse: 'hyperlapse, dynamic movement, urban, travel',
        stopmotion: 'stop motion animation, creative, artistic',
        vlog: 'vlog style, personal, casual, authentic',
        corporate: 'corporate style, professional, clean, business-oriented',
    };

    /**
     * Generate a video
     */
    async generateVideo(request: VideoGenerationRequest): Promise<GeneratedVideo> {
        const {
            prompt,
            duration = '15s',
            aspectRatio = '9:16',
            style = 'cinematic',
            motion = 'static',
            audio,
            platform,
        } = request;

        // Apply platform defaults
        let finalDuration = duration;
        let finalRatio = aspectRatio;
        let finalStyle = style;

        if (platform && this.platformDefaults[platform]) {
            const defaults = this.platformDefaults[platform];
            finalDuration = defaults.duration;
            finalRatio = defaults.aspectRatio;
            finalStyle = defaults.style;
        }

        // Get resolution based on aspect ratio
        const resolution = this.getResolution(finalRatio);
        const frames = this.calculateFrames(finalDuration);

        // Mock generation (in production, this would call Veo API)
        const video: GeneratedVideo = {
            id: `vid-${Date.now()}`,
            prompt,
            url: `https://test-videos.co.uk/vids/bigbuckbunny/mp4/h264/720/Big_Buck_Bunny_720_10s_1MB.mp4`,
            thumbnailUrl: `https://storage.example.com/videos/${Date.now()}_thumb.jpg`,
            duration: finalDuration,
            aspectRatio: finalRatio,
            style: finalStyle,
            resolution,
            fps: 30,
            fileSize: this.estimateFileSize(finalDuration, resolution),
            metadata: {
                model: 'veo-2.0',
                generationTime: 15000 + Math.random() * 10000,
                frames,
                hasAudio: !!audio?.music || !!audio?.voiceover,
                audioTrack: audio?.music,
                tags: this.extractTags(prompt),
            },
            status: 'completed',
            createdAt: new Date(),
        };

        this.logger.log(`Generated video: ${video.id}`);
        return video;
    }

    /**
     * Generate video from image (image-to-video)
     */
    async imageToVideo(
        imageUrl: string,
        motion: MotionType = 'zoom_in',
        duration: VideoDuration = '5s',
    ): Promise<GeneratedVideo> {
        return this.generateVideo({
            prompt: `Animate image with ${motion} motion`,
            duration,
            motion,
        });
    }

    /**
     * Generate multi-scene video
     */
    async generateMultiSceneVideo(
        scenes: VideoScene[],
        audio?: AudioOptions,
    ): Promise<GeneratedVideo> {
        const totalDuration = scenes.reduce((sum, scene) => {
            const seconds = parseInt(scene.duration.replace('s', ''));
            return sum + seconds;
        }, 0);

        const combinedPrompt = scenes.map((s) => s.prompt).join(' | ');

        return this.generateVideo({
            prompt: combinedPrompt,
            duration: `${totalDuration}s` as VideoDuration,
            audio,
        });
    }

    /**
     * Get video generation status
     */
    async getVideoStatus(videoId: string): Promise<{
        status: VideoStatus;
        progress: number;
        estimatedRemaining?: number;
    }> {
        // Mock status check
        return {
            status: 'completed',
            progress: 100,
        };
    }

    /**
     * Get platform recommendations
     */
    getPlatformRecommendations(platform: string): {
        duration: VideoDuration;
        aspectRatio: VideoAspectRatio;
        style: VideoStyle;
        tips: string[];
    } | null {
        const defaults = this.platformDefaults[platform];
        if (!defaults) return null;

        return {
            ...defaults,
            tips: this.getPlatformTips(platform),
        };
    }

    /**
     * Get available styles
     */
    getStyles(): { style: VideoStyle; description: string }[] {
        return Object.entries(this.styleModifiers).map(([style, description]) => ({
            style: style as VideoStyle,
            description: description.split(',')[0],
        }));
    }

    /**
     * Get available motions
     */
    getMotions(): { motion: MotionType; description: string }[] {
        const descriptions: Record<MotionType, string> = {
            static: 'No camera movement',
            pan_left: 'Camera pans from right to left',
            pan_right: 'Camera pans from left to right',
            zoom_in: 'Camera zooms in towards subject',
            zoom_out: 'Camera zooms out from subject',
            dolly_in: 'Camera moves forward',
            dolly_out: 'Camera moves backward',
            orbit: 'Camera orbits around subject',
            tilt_up: 'Camera tilts upward',
            tilt_down: 'Camera tilts downward',
        };

        return Object.entries(descriptions).map(([motion, description]) => ({
            motion: motion as MotionType,
            description,
        }));
    }

    // Private helper methods

    private getResolution(aspectRatio: VideoAspectRatio): VideoResolution {
        const resolutions: Record<VideoAspectRatio, VideoResolution> = {
            '1:1': { width: 1080, height: 1080, quality: '1080p' },
            '9:16': { width: 1080, height: 1920, quality: '1080p' },
            '16:9': { width: 1920, height: 1080, quality: '1080p' },
            '4:5': { width: 1080, height: 1350, quality: '1080p' },
        };
        return resolutions[aspectRatio];
    }

    private calculateFrames(duration: VideoDuration): number {
        const seconds = parseInt(duration.replace('s', ''));
        return seconds * 30; // 30 fps
    }

    private estimateFileSize(duration: VideoDuration, resolution: VideoResolution): number {
        const seconds = parseInt(duration.replace('s', ''));
        const baseSize = resolution.quality === '4k' ? 50 : resolution.quality === '1080p' ? 20 : 10;
        return seconds * baseSize * 1024 * 1024; // MB to bytes
    }

    private extractTags(prompt: string): string[] {
        const words = prompt.toLowerCase().split(/\s+/);
        return words.filter((w) => w.length > 3).slice(0, 10);
    }

    private getPlatformTips(platform: string): string[] {
        const tips: Record<string, string[]> = {
            tiktok: [
                'Hook viewers in first 3 seconds',
                'Use trending sounds',
                'Include text overlays',
                'End with a loop-friendly transition',
            ],
            instagram_reel: [
                'Start with an attention-grabbing moment',
                'Use vertical format fully',
                'Add captions for sound-off viewing',
                'Keep it under 30 seconds for best engagement',
            ],
            youtube_short: [
                'Vertical format required',
                'First 2 seconds are critical',
                'Add a clear CTA',
                'Hashtags help discovery',
            ],
            linkedin: [
                'Keep professional tone',
                'Add captions (most watch on mute)',
                'Lead with value',
                'Optimal length: 30-90 seconds',
            ],
        };

        return tips[platform] || ['Optimize for the platform guidelines'];
    }
}