import { z } from 'zod';
import fs from 'fs/promises';
import path from 'path';
import { fileURLToPath } from 'url';

const __dirname = path.dirname(fileURLToPath(import.meta.url));

const ConfigSchema = z.object({
  github: z.object({
    token: z.string().min(10, 'GITHUB_TOKEN must be a valid token'),
    owner: z.string().min(1, 'GITHUB_OWNER is required'),
    repo: z.string().min(1, 'GITHUB_REPO is required'),
  }),
  ai: z.object({
    provider: z.enum(['ollama', 'huggingface', 'groq', 'openrouter', 'fallback']).default('fallback'),
    ollama: z.object({
      model: z.string().default('llama3.2'),
      baseUrl: z.string().default('http://localhost:11434'),
      timeout: z.number().min(1000).max(120000).default(60000),
      maxRetries: z.number().min(0).max(10).default(3),
    }),
    huggingface: z.object({
      apiKey: z.string().default(''),
      model: z.string().default('mistralai/Mistral-7B-Instruct-v0.2'),
      timeout: z.number().min(1000).max(120000).default(60000),
      maxRetries: z.number().min(0).max(10).default(3),
    }),
    groq: z.object({
      apiKey: z.string().default(''),
      model: z.string().default('llama-3.1-8b-instant'),
      timeout: z.number().min(1000).max(120000).default(30000),
      maxRetries: z.number().min(0).max(10).default(3),
    }),
    openrouter: z.object({
      apiKey: z.string().default(''),
      model: z.string().default('meta-llama/llama-3.1-8b-instruct:free'),
      timeout: z.number().min(1000).max(120000).default(30000),
      maxRetries: z.number().min(0).max(10).default(3),
    }),
  }),
  schedule: z.object({
    timezone: z.string().default('Africa/Cairo'),
    noWorkHoursRestriction: z.boolean().default(true),
  }),
  activity: z.object({
    minIntervalMinutes: z.number().min(1).max(1440).default(5),
    maxIntervalMinutes: z.number().min(1).max(1440).default(45),
    maxCommitsPerSession: z.number().min(1).max(50).default(8),
    maxFilesPerCommit: z.number().min(1).max(20).default(3),
    bugProbability: z.number().min(0).max(1).default(0.15),
    typoProbability: z.number().min(0).max(1).default(0.1),
    maxActionsPerCycle: z.number().min(1).max(10).default(3),
  }),
  daemon: z.object({
    enabled: z.boolean().default(true),
    checkIntervalMinutes: z.number().min(1).max(120).default(10),
    maxCyclesBeforeRestart: z.number().min(10).max(1000).default(100),
  }),
  memory: z.object({
    persistToFile: z.boolean().default(true),
    persistIntervalMinutes: z.number().min(1).max(60).default(15),
    maxHistorySize: z.number().min(100).max(10000).default(500),
    maxDecisionsSize: z.number().min(50).max(5000).default(200),
  }),
  logging: z.object({
    level: z.enum(['debug', 'info', 'warn', 'error']).default('info'),
    file: z.string().default('logs/simulator.log'),
    maxFileSize: z.number().min(1000000).max(100000000).default(10000000),
  }),
});

export function loadConfig() {
  const rawConfig = {
    github: {
      token: process.env.GITHUB_TOKEN,
      owner: process.env.GITHUB_OWNER,
      repo: process.env.GITHUB_REPO,
    },
    ai: {
      provider: process.env.AI_PROVIDER || 'fallback',
      ollama: {
        model: process.env.OLLAMA_MODEL || 'llama3.2',
        baseUrl: process.env.OLLAMA_BASE_URL || 'http://localhost:11434',
        timeout: parseInt(process.env.OLLAMA_TIMEOUT) || 60000,
        maxRetries: parseInt(process.env.OLLAMA_MAX_RETRIES) || 3,
      },
      huggingface: {
        apiKey: process.env.HUGGINGFACE_API_KEY || '',
        model: process.env.HUGGINGFACE_MODEL || 'mistralai/Mistral-7B-Instruct-v0.2',
        timeout: parseInt(process.env.HUGGINGFACE_TIMEOUT) || 60000,
        maxRetries: parseInt(process.env.HUGGINGFACE_MAX_RETRIES) || 3,
      },
      groq: {
        apiKey: process.env.GROQ_API_KEY || '',
        model: process.env.GROQ_MODEL || 'llama-3.1-8b-instant',
        timeout: parseInt(process.env.GROQ_TIMEOUT) || 30000,
        maxRetries: parseInt(process.env.GROQ_MAX_RETRIES) || 3,
      },
      openrouter: {
        apiKey: process.env.OPENROUTER_API_KEY || '',
        model: process.env.OPENROUTER_MODEL || 'meta-llama/llama-3.1-8b-instruct:free',
        timeout: parseInt(process.env.OPENROUTER_TIMEOUT) || 30000,
        maxRetries: parseInt(process.env.OPENROUTER_MAX_RETRIES) || 3,
      },
    },
    schedule: {
      timezone: process.env.TIMEZONE || 'Africa/Cairo',
      noWorkHoursRestriction: process.env.NO_WORK_HOURS_RESTRICTION !== 'false',
    },
    activity: {
      minIntervalMinutes: _parseInt(process.env.MIN_ACTIVITY_INTERVAL_MINUTES, 5),
      maxIntervalMinutes: _parseInt(process.env.MAX_ACTIVITY_INTERVAL_MINUTES, 45),
      maxCommitsPerSession: _parseInt(process.env.MAX_COMMITS_PER_SESSION, 8),
      maxFilesPerCommit: _parseInt(process.env.MAX_FILES_PER_COMMIT, 3),
      bugProbability: _parseFloat(process.env.BUG_PROBABILITY, 0.15),
      typoProbability: _parseFloat(process.env.TYPO_PROBABILITY, 0.1),
      maxActionsPerCycle: _parseInt(process.env.MAX_ACTIONS_PER_CYCLE, 3),
    },
    daemon: {
      enabled: process.env.DAEMON_ENABLED !== 'false',
      checkIntervalMinutes: _parseInt(process.env.DAEMON_CHECK_INTERVAL_MINUTES, 10),
      maxCyclesBeforeRestart: _parseInt(process.env.MAX_CYCLES_BEFORE_RESTART, 100),
    },
    memory: {
      persistToFile: process.env.MEMORY_PERSIST_TO_FILE !== 'false',
      persistIntervalMinutes: _parseInt(process.env.MEMORY_PERSIST_INTERVAL_MINUTES, 15),
      maxHistorySize: _parseInt(process.env.MEMORY_MAX_HISTORY_SIZE, 500),
      maxDecisionsSize: _parseInt(process.env.MEMORY_MAX_DECISIONS_SIZE, 200),
    },
    logging: {
      level: process.env.LOG_LEVEL || 'info',
      file: process.env.LOG_FILE || 'logs/simulator.log',
      maxFileSize: _parseInt(process.env.LOG_MAX_FILE_SIZE, 10000000),
    },
  };

  try {
    return ConfigSchema.parse(rawConfig);
  } catch (error) {
    const formattedErrors = error.errors
      .map(e => `  - ${e.path.join('.')}: ${e.message}`)
      .join('\n');
    throw new Error(`Invalid configuration:\n${formattedErrors}`);
  }
}

export async function saveConfig(config, filePath = '.env') {
  const envContent = `GITHUB_TOKEN=${config.github.token}
GITHUB_OWNER=${config.github.owner}
GITHUB_REPO=${config.github.repo}
AI_PROVIDER=${config.ai.provider}
OLLAMA_MODEL=${config.ai.ollama.model}
OLLAMA_BASE_URL=${config.ai.ollama.baseUrl}
HUGGINGFACE_API_KEY=${config.ai.huggingface.apiKey}
HUGGINGFACE_MODEL=${config.ai.huggingface.model}
TIMEZONE=${config.schedule.timezone}
NO_WORK_HOURS_RESTRICTION=true
MIN_ACTIVITY_INTERVAL_MINUTES=${config.activity.minIntervalMinutes}
MAX_ACTIVITY_INTERVAL_MINUTES=${config.activity.maxIntervalMinutes}
MAX_COMMITS_PER_SESSION=${config.activity.maxCommitsPerSession}
MAX_FILES_PER_COMMIT=${config.activity.maxFilesPerCommit}
BUG_PROBABILITY=${config.activity.bugProbability}
TYPO_PROBABILITY=${config.activity.typoProbability}
DAEMON_ENABLED=${config.daemon.enabled}
DAEMON_CHECK_INTERVAL_MINUTES=${config.daemon.checkIntervalMinutes}
MEMORY_PERSIST_TO_FILE=${config.memory.persistToFile}
MEMORY_PERSIST_INTERVAL_MINUTES=${config.memory.persistIntervalMinutes}
LOG_LEVEL=${config.logging.level}
LOG_FILE=${config.logging.file}
`;

  await fs.writeFile(filePath, envContent, 'utf8');
}

export function validateConfig(config) {
  try {
    ConfigSchema.parse(config);
    return { valid: true, errors: [] };
  } catch (error) {
    return {
      valid: false,
      errors: error.errors.map(e => `${e.path.join('.')}: ${e.message}`),
    };
  }
}

function _parseInt(value, defaultValue) {
  if (value === undefined || value === null || value === '') return defaultValue;
  const parsed = parseInt(value, 10);
  return isNaN(parsed) ? defaultValue : parsed;
}

function _parseFloat(value, defaultValue) {
  if (value === undefined || value === null || value === '') return defaultValue;
  const parsed = parseFloat(value);
  return isNaN(parsed) ? defaultValue : parsed;
}

export default loadConfig;