const fs = require('fs');
const path = require('path');
const https = require('https');
const http = require('http');
const { getDb } = require('../db');

const AI_CONFIG_PATH = path.join(__dirname, '..', 'data', 'ai_config.json');

const PROVIDER_PRESETS = {
  openrouter: {
    label: 'OpenRouter',
    base_url: 'https://openrouter.ai/api/v1',
    models: ['qwen/qwen3-coder:free', 'meta-llama/llama-3.3-70b-instruct:free', 'google/gemma-3-27b-it:free', 'anthropic/claude-3.5-sonnet', 'openai/gpt-4o-mini']
  },
  openai: {
    label: 'OpenAI',
    base_url: 'https://api.openai.com/v1',
    models: ['gpt-4o', 'gpt-4o-mini', 'gpt-4-turbo', 'o1-mini']
  },
  anthropic: {
    label: 'Anthropic',
    base_url: 'https://api.anthropic.com/v1',
    models: ['claude-3-5-sonnet-20241022', 'claude-3-5-haiku-20241022', 'claude-3-opus-20240229']
  },
  deepseek: {
    label: 'DeepSeek',
    base_url: 'https://api.deepseek.com/v1',
    models: ['deepseek-chat', 'deepseek-reasoner']
  },
  groq: {
    label: 'Groq',
    base_url: 'https://api.groq.com/openai/v1',
    models: ['llama-3.3-70b-versatile', 'mixtral-8x7b-32768']
  },
  ollama: {
    label: 'Ollama (local)',
    base_url: 'http://localhost:11434/v1',
    models: ['llama3.2', 'mistral', 'codellama', 'qwen2.5']
  },
  azure: {
    label: 'Azure OpenAI',
    base_url: '',
    models: ['gpt-4o', 'gpt-4o-mini']
  },
  custom: {
    label: 'Custom (OpenAI-compatible)',
    base_url: '',
    models: []
  }
};

function initAiSchema() {
  const db = getDb();
  db.exec(`
    CREATE TABLE IF NOT EXISTS ai_providers (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      name TEXT NOT NULL,
      provider_type TEXT NOT NULL DEFAULT 'openrouter',
      api_key TEXT DEFAULT '',
      base_url TEXT DEFAULT '',
      default_model TEXT DEFAULT '',
      is_active INTEGER DEFAULT 1,
      is_default INTEGER DEFAULT 0,
      extra_headers TEXT DEFAULT '{}',
      created_at TEXT DEFAULT (datetime('now')),
      updated_at TEXT DEFAULT (datetime('now'))
    );
    CREATE TABLE IF NOT EXISTS integrations (
      id TEXT PRIMARY KEY,
      name TEXT DEFAULT '',
      api_key TEXT DEFAULT '',
      webhook_url TEXT DEFAULT '',
      config TEXT DEFAULT '{}',
      status TEXT DEFAULT 'inactive',
      created_at TEXT DEFAULT (datetime('now'))
    );
  `);

  const count = db.prepare('SELECT COUNT(*) as c FROM ai_providers').get().c;
  if (count === 0 && process.env.DEEPSEEK_API_KEY) {
    db.prepare(`INSERT INTO ai_providers (name, provider_type, api_key, base_url, default_model, is_default)
      VALUES (?, ?, ?, ?, ?, 1)`).run(
      'OpenRouter Default', 'openrouter', process.env.DEEPSEEK_API_KEY,
      'https://openrouter.ai/api/v1', 'qwen/qwen3-coder:free'
    );
  }
}

let _aiSchemaReady = false;
function ensureAiSchema() {
  if (_aiSchemaReady) return;
  initAiSchema();
  _aiSchemaReady = true;
}

function getProviders() {
  ensureAiSchema();
  return getDb().prepare('SELECT id, name, provider_type, base_url, default_model, is_active, is_default, created_at, updated_at FROM ai_providers ORDER BY is_default DESC, name').all();
}

function getProvider(id) {
  ensureAiSchema();
  return getDb().prepare('SELECT * FROM ai_providers WHERE id = ?').get(id);
}

function getDefaultProvider() {
  ensureAiSchema();
  let p = getDb().prepare('SELECT * FROM ai_providers WHERE is_default = 1 AND is_active = 1 LIMIT 1').get();
  if (!p) p = getDb().prepare('SELECT * FROM ai_providers WHERE is_active = 1 ORDER BY id LIMIT 1').get();
  return p;
}

function saveProvider(data) {
  ensureAiSchema();
  const db = getDb();
  if (data.is_default) {
    db.prepare('UPDATE ai_providers SET is_default = 0').run();
  }
  if (data.id) {
    db.prepare(`UPDATE ai_providers SET name=?, provider_type=?, api_key=?, base_url=?, default_model=?,
      is_active=?, is_default=?, updated_at=datetime('now') WHERE id=?`).run(
      data.name, data.provider_type, data.api_key || '', data.base_url || '',
      data.default_model || '', data.is_active ? 1 : 0, data.is_default ? 1 : 0, data.id
    );
    syncAiConfigFile();
    return data.id;
  }
  const r = db.prepare(`INSERT INTO ai_providers (name, provider_type, api_key, base_url, default_model, is_active, is_default)
    VALUES (?, ?, ?, ?, ?, ?, ?)`).run(
    data.name, data.provider_type, data.api_key || '', data.base_url || '',
    data.default_model || '', data.is_active !== false ? 1 : 0, data.is_default ? 1 : 0
  );
  syncAiConfigFile();
  return r.lastInsertRowid;
}

function deleteProvider(id) {
  ensureAiSchema();
  getDb().prepare('DELETE FROM ai_providers WHERE id = ?').run(id);
  syncAiConfigFile();
}

function syncAiConfigFile() {
  ensureAiSchema();
  const providers = getDb().prepare('SELECT * FROM ai_providers WHERE is_active = 1').all();
  const defaultProvider = providers.find(p => p.is_default) || providers[0] || null;
  const config = {
    default_provider_id: defaultProvider?.id || null,
    providers: providers.map(p => ({
      id: p.id,
      name: p.name,
      provider_type: p.provider_type,
      api_key: p.api_key,
      base_url: p.base_url || PROVIDER_PRESETS[p.provider_type]?.base_url || '',
      default_model: p.default_model,
      is_default: !!p.is_default
    }))
  };
  const dir = path.dirname(AI_CONFIG_PATH);
  if (!fs.existsSync(dir)) fs.mkdirSync(dir, { recursive: true });
  fs.writeFileSync(AI_CONFIG_PATH, JSON.stringify(config, null, 2));

  const leadgenConfig = {
    api_key: defaultProvider?.api_key || process.env.DEEPSEEK_API_KEY || '',
    base_url: defaultProvider?.base_url || 'https://openrouter.ai/api/v1',
    model: defaultProvider?.default_model || 'qwen/qwen3-coder:free',
    provider_type: defaultProvider?.provider_type || 'openrouter'
  };
  fs.writeFileSync(path.join(dir, 'leadgen_config.json'), JSON.stringify(leadgenConfig, null, 2));
}

function maskKey(key) {
  if (!key || key.length < 8) return key ? '••••••••' : '';
  return key.slice(0, 6) + '••••' + key.slice(-4);
}

function chatCompletion(messages, options = {}) {
  return new Promise((resolve, reject) => {
    const provider = options.providerId
      ? getProvider(options.providerId)
      : getDefaultProvider();
    if (!provider || !provider.api_key) {
      return reject(new Error('Geen actieve AI provider geconfigureerd. Ga naar /ai om een provider toe te voegen.'));
    }

    const preset = PROVIDER_PRESETS[provider.provider_type] || PROVIDER_PRESETS.custom;
    const baseUrl = provider.base_url || preset.base_url;
    const model = options.model || provider.default_model || preset.models[0];

    let url;
    try {
      url = new URL('/chat/completions', baseUrl.endsWith('/') ? baseUrl : baseUrl + '/');
    } catch (e) {
      return reject(new Error('Ongeldige base URL: ' + baseUrl));
    }

    const body = JSON.stringify({
      model,
      messages,
      temperature: options.temperature ?? 0.7,
      max_tokens: options.max_tokens ?? 4096
    });

    const isHttps = url.protocol === 'https:';
    const lib = isHttps ? https : http;
    const headers = {
      'Content-Type': 'application/json',
      'Content-Length': Buffer.byteLength(body)
    };

    if (provider.provider_type === 'anthropic') {
      headers['x-api-key'] = provider.api_key;
      headers['anthropic-version'] = '2023-06-01';
    } else {
      headers['Authorization'] = `Bearer ${provider.api_key}`;
    }
    if (provider.provider_type === 'openrouter') {
      headers['HTTP-Referer'] = process.env.BASE_URL || 'http://localhost:3000';
      headers['X-Title'] = 'Mek-Tech Platform';
    }

    const reqOpts = {
      hostname: url.hostname,
      port: url.port || (isHttps ? 443 : 80),
      path: url.pathname,
      method: 'POST',
      headers,
      timeout: 120000
    };

    const req = lib.request(reqOpts, (res) => {
      let data = '';
      res.on('data', c => { data += c; });
      res.on('end', () => {
        try {
          const parsed = JSON.parse(data);
          if (res.statusCode >= 400) {
            reject(new Error(parsed.error?.message || parsed.message || data.slice(0, 200)));
          } else {
            resolve(parsed);
          }
        } catch (e) {
          reject(new Error('AI response parse error: ' + data.slice(0, 200)));
        }
      });
    });
    req.on('error', reject);
    req.on('timeout', () => { req.destroy(); reject(new Error('AI request timeout')); });
    req.write(body);
    req.end();
  });
}

module.exports = {
  PROVIDER_PRESETS,
  initAiSchema: ensureAiSchema,
  getProviders,
  getProvider,
  getDefaultProvider,
  saveProvider,
  deleteProvider,
  syncAiConfigFile,
  maskKey,
  chatCompletion
};