// Platform Adapters Service - Transform content for different platforms
// Path: src/modules/content/services/platform-adapters.service.ts

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

export interface PlatformConfig {
    name: string;
    maxLength: number;
    supportsMedia: boolean;
    supportsLinks: boolean;
    supportsHashtags: boolean;
    supportsMentions: boolean;
    supportsEmoji: boolean;
    mediaFormats?: string[];
    optimalLength?: number;
    bestPostingTimes?: string[];
    engagementTips?: string[];
}

export const PLATFORM_CONFIGS: Record<SocialPlatform, PlatformConfig> = {
    TWITTER: {
        name: 'X (Twitter)',
        maxLength: 280,
        optimalLength: 240,
        supportsMedia: true,
        supportsLinks: true,
        supportsHashtags: true,
        supportsMentions: true,
        supportsEmoji: true,
        mediaFormats: ['image', 'video', 'gif'],
        bestPostingTimes: ['9:00', '12:00', '17:00', '21:00'],
        engagementTips: [
            'Use threads for longer content',
            'Ask questions to boost engagement',
            'Quote tweet with commentary',
        ],
    },
    LINKEDIN: {
        name: 'LinkedIn',
        maxLength: 3000,
        optimalLength: 1300,
        supportsMedia: true,
        supportsLinks: true,
        supportsHashtags: true,
        supportsMentions: true,
        supportsEmoji: true,
        mediaFormats: ['image', 'video', 'document', 'carousel'],
        bestPostingTimes: ['7:30', '12:00', '17:00'],
        engagementTips: [
            'Hook in first line (before "see more")',
            'Use line breaks for readability',
            'End with a question',
        ],
    },
    INSTAGRAM: {
        name: 'Instagram',
        maxLength: 2200,
        optimalLength: 1500,
        supportsMedia: true,
        supportsLinks: false,
        supportsHashtags: true,
        supportsMentions: true,
        supportsEmoji: true,
        mediaFormats: ['image', 'video', 'reels', 'carousel', 'stories'],
        bestPostingTimes: ['6:00', '11:00', '19:00'],
        engagementTips: [
            'Use up to 30 hashtags',
            'Put hashtags in first comment',
            'Include CTA in caption',
        ],
    },
    FACEBOOK: {
        name: 'Facebook',
        maxLength: 63206,
        optimalLength: 250,
        supportsMedia: true,
        supportsLinks: true,
        supportsHashtags: true,
        supportsMentions: true,
        supportsEmoji: true,
        mediaFormats: ['image', 'video', 'reels', 'stories'],
        bestPostingTimes: ['9:00', '13:00', '19:00'],
        engagementTips: [
            'Shorter posts perform better',
            'Native video preferred',
            'Use Facebook Live for engagement',
        ],
    },
    TIKTOK: {
        name: 'TikTok',
        maxLength: 300,
        optimalLength: 150,
        supportsMedia: true,
        supportsLinks: false,
        supportsHashtags: true,
        supportsMentions: true,
        supportsEmoji: true,
        mediaFormats: ['video'],
        bestPostingTimes: ['7:00', '10:00', '19:00', '23:00'],
        engagementTips: [
            'Hook in first 3 seconds',
            'Use trending sounds',
            'Keep videos under 60 seconds',
        ],
    },
    YOUTUBE: {
        name: 'YouTube',
        maxLength: 5000,
        optimalLength: 500,
        supportsMedia: true,
        supportsLinks: true,
        supportsHashtags: true,
        supportsMentions: false,
        supportsEmoji: true,
        mediaFormats: ['video', 'shorts'],
        bestPostingTimes: ['12:00', '15:00', '19:00'],
        engagementTips: [
            'Use timestamps in description',
            'Include relevant keywords',
            'Add cards and end screens',
        ],
    },
    PINTEREST: {
        name: 'Pinterest',
        maxLength: 500,
        optimalLength: 300,
        supportsMedia: true,
        supportsLinks: true,
        supportsHashtags: true,
        supportsMentions: false,
        supportsEmoji: true,
        mediaFormats: ['image', 'video', 'idea_pin'],
        bestPostingTimes: ['20:00', '21:00', '22:00'],
        engagementTips: [
            'Vertical images perform best',
            'Use keyword-rich descriptions',
            'Create multiple pins per post',
        ],
    },
    THREADS: {
        name: 'Threads',
        maxLength: 500,
        optimalLength: 280,
        supportsMedia: true,
        supportsLinks: false,
        supportsHashtags: false,
        supportsMentions: true,
        supportsEmoji: true,
        mediaFormats: ['image', 'video'],
        bestPostingTimes: ['12:00', '17:00', '21:00'],
        engagementTips: [
            'Conversational tone works best',
            'Reply to trending topics',
            'Cross-post from Instagram',
        ],
    },
};

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

    /**
     * Get platform configuration
     */
    getConfig(platform: SocialPlatform): PlatformConfig {
        return PLATFORM_CONFIGS[platform];
    }

    /**
     * Get all platform configs
     */
    getAllConfigs(): Record<SocialPlatform, PlatformConfig> {
        return PLATFORM_CONFIGS;
    }

    /**
     * Adapt content for specific platform
     */
    adapt(content: string, sourcePlatform: SocialPlatform, targetPlatform: SocialPlatform): string {
        const sourceConfig = PLATFORM_CONFIGS[sourcePlatform];
        const targetConfig = PLATFORM_CONFIGS[targetPlatform];

        let adapted = content;

        // Handle length constraints
        if (adapted.length > targetConfig.maxLength) {
            adapted = this.truncate(adapted, targetConfig.maxLength);
        }

        // Handle link support
        if (!targetConfig.supportsLinks && sourceConfig.supportsLinks) {
            adapted = this.removeLinks(adapted);
        }

        // Handle hashtag support
        if (!targetConfig.supportsHashtags && sourceConfig.supportsHashtags) {
            adapted = this.removeHashtags(adapted);
        }

        return adapted;
    }

    /**
     * Format content for platform
     */
    format(content: string, platform: SocialPlatform): string {
        const config = PLATFORM_CONFIGS[platform];

        switch (platform) {
            case 'TWITTER':
                return this.formatForTwitter(content, config);
            case 'LINKEDIN':
                return this.formatForLinkedIn(content, config);
            case 'INSTAGRAM':
                return this.formatForInstagram(content, config);
            default:
                return this.truncate(content, config.maxLength);
        }
    }

    /**
     * Check if content is valid for platform
     */
    validate(content: string, platform: SocialPlatform): { valid: boolean; issues: string[] } {
        const config = PLATFORM_CONFIGS[platform];
        const issues: string[] = [];

        if (content.length > config.maxLength) {
            issues.push(`Content exceeds ${config.maxLength} character limit`);
        }

        if (!config.supportsLinks && this.containsLinks(content)) {
            issues.push('Platform does not support links in captions');
        }

        return { valid: issues.length === 0, issues };
    }

    // Private helpers
    private truncate(content: string, maxLength: number): string {
        if (content.length <= maxLength) return content;
        return content.substring(0, maxLength - 3) + '...';
    }

    private removeLinks(content: string): string {
        return content.replace(/https?:\/\/[^\s]+/g, '[link in bio]');
    }

    private removeHashtags(content: string): string {
        return content.replace(/#\w+/g, '').replace(/\s+/g, ' ').trim();
    }

    private containsLinks(content: string): boolean {
        return /https?:\/\/[^\s]+/.test(content);
    }

    private formatForTwitter(content: string, config: PlatformConfig): string {
        let formatted = content;

        // Ensure hashtags at end
        const hashtags = formatted.match(/#\w+/g) || [];
        formatted = formatted.replace(/#\w+/g, '').trim();
        formatted = `${formatted}\n\n${hashtags.slice(0, 3).join(' ')}`;

        return this.truncate(formatted, config.maxLength);
    }

    private formatForLinkedIn(content: string, config: PlatformConfig): string {
        // Add line breaks for readability
        const lines = content.split(/(?<=[.!?])\s+/);
        return lines.slice(0, 20).join('\n\n');
    }

    private formatForInstagram(content: string, config: PlatformConfig): string {
        let formatted = content;

        // Add dots before hashtags (common Instagram style)
        if (formatted.includes('#')) {
            const mainContent = formatted.split('#')[0].trim();
            const hashtags = formatted.match(/#\w+/g) || [];
            formatted = `${mainContent}\n.\n.\n.\n${hashtags.join(' ')}`;
        }

        return formatted;
    }
}