import asyncio
import json
import os
import logging
from typing import Dict, List, Optional
from datetime import datetime
import sys

import discord
from discord.ext import commands
import aiohttp
import anthropic
from github import Github
from flask import Flask, request, jsonify
import threading
import time

# Configure logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

class GitHubCodeReviewBot:
    def __init__(self):
        # Configuration from environment variables
        self.discord_token = os.getenv('DISCORD_TOKEN')
        self.github_token = os.getenv('GITHUB_TOKEN')
        self.anthropic_api_key = os.getenv('ANTHROPIC_API_KEY')
        self.target_repo = os.getenv('TARGET_REPO')  # format: "owner/repo"
        self.target_user = os.getenv('TARGET_USER')  # GitHub username to monitor
        self.discord_channel_id = int(os.getenv('DISCORD_CHANNEL_ID', 0))
        self.webhook_secret = os.getenv('WEBHOOK_SECRET', '')

        
        # Validate required environment variables
        self._validate_config()
        
        # Initialize clients with error handling
        self._initialize_clients()
        
        # Discord bot setup
        intents = discord.Intents.default()
        intents.message_content = True
        self.bot = commands.Bot(command_prefix='!', intents=intents)
        
        # Flask app for webhook
        self.app = Flask(__name__)
        self.setup_webhook_routes()
        self.setup_discord_events()
        
    def _validate_config(self):
        """Validate required configuration"""
        required_vars = {
            'DISCORD_TOKEN': self.discord_token,
            'GITHUB_TOKEN': self.github_token,
            'ANTHROPIC_API_KEY': self.anthropic_api_key,
            'TARGET_REPO': self.target_repo,
            'TARGET_USER': self.target_user,
            'DISCORD_CHANNEL_ID': self.discord_channel_id
        }
        
        missing_vars = [var for var, value in required_vars.items() if not value]
        if missing_vars:
            logger.error(f"Missing required environment variables: {missing_vars}")
            sys.exit(1)
            
    def _initialize_clients(self):
        """Initialize API clients with error handling"""
        try:
            # For classic tokens, no special configuration needed
            self.github_client = Github(self.github_token)
            # Test the connection
            user = self.github_client.get_user()
            logger.info(f"GitHub client initialized successfully as user: {user.login}")
        except Exception as e:
            logger.error(f"Failed to initialize GitHub client: {e}")
            sys.exit(1)
            
        try:
            # Try different initialization methods for Anthropic
            self.anthropic_client = anthropic.Anthropic(api_key=self.anthropic_api_key)
            logger.info("Anthropic client initialized successfully")
        except Exception as e:
            logger.error(f"Failed to initialize Anthropic client: {e}")
            logger.info("Attempting alternative initialization...")
            try:
                # Alternative initialization
                import anthropic
                self.anthropic_client = anthropic.Client(api_key=self.anthropic_api_key)
                logger.info("Anthropic client initialized with alternative method")
            except Exception as e2:
                logger.error(f"Alternative initialization also failed: {e2}")
                logger.warning("Anthropic client not available - code review will be disabled")
                self.anthropic_client = None
    
    def setup_webhook_routes(self):
        """Setup Flask routes for GitHub webhook"""
        @self.app.route('/webhook', methods=['POST'])
        def handle_webhook():
            try:
                payload = request.get_json()
                
                if not payload:
                    return jsonify({'error': 'No payload received'}), 400
                
                # Verify webhook (basic security)
                if self.webhook_secret:
                    signature = request.headers.get('X-Hub-Signature-256')
                    if not self.verify_webhook_signature(request.data, signature):
                        logger.warning("Invalid webhook signature")
                        return jsonify({'error': 'Invalid signature'}), 401
                
                # Handle push events
                if 'commits' in payload and payload.get('commits'):
                    logger.info(f"Received push event for {payload['repository']['full_name']}")
                    asyncio.run_coroutine_threadsafe(
                        self.handle_push_event(payload), 
                        self.bot.loop
                    )
                
                return jsonify({'status': 'ok'}), 200
                
            except Exception as e:
                logger.error(f"Webhook error: {e}")
                return jsonify({'error': str(e)}), 500
        
        @self.app.route('/health', methods=['GET'])
        def health_check():
            return jsonify({
                'status': 'healthy',
                'timestamp': datetime.now().isoformat(),
                'monitoring': f"{self.target_repo} for user {self.target_user}"
            }), 200
    
    def verify_webhook_signature(self, payload_body, signature_header):
        """Verify GitHub webhook signature"""
        import hmac
        import hashlib
        
        if not signature_header:
            return False
            
        try:
            hash_object = hmac.new(
                self.webhook_secret.encode('utf-8'),
                payload_body,
                hashlib.sha256
            )
            expected_signature = "sha256=" + hash_object.hexdigest()
            return hmac.compare_digest(expected_signature, signature_header)
        except Exception as e:
            logger.error(f"Signature verification error: {e}")
            return False
    
    def setup_discord_events(self):
        """Setup Discord bot events"""
        @self.bot.event
        async def on_ready():
            logger.info(f'{self.bot.user} has connected to Discord!')
            
            # Test channel access
            try:
                channel = self.bot.get_channel(self.discord_channel_id)
                if channel:
                    logger.info(f"Successfully connected to Discord channel: {channel.name}")
                    await channel.send("🤖 Code Review Bot is now online and monitoring commits!")
                else:
                    logger.error(f"Could not find Discord channel with ID: {self.discord_channel_id}")
            except Exception as e:
                logger.error(f"Error sending startup message: {e}")
            
        @self.bot.event
        async def on_error(event, *args, **kwargs):
            logger.error(f"Discord error in {event}: {args}, {kwargs}")
            
        @self.bot.command(name='status')
        async def status(ctx):
            """Check bot status"""
            status_msg = f"""
🤖 **Bot Status**
📁 Monitoring: `{self.target_repo}`
👤 Target User: `{self.target_user}`
🔧 Anthropic API: {'✅ Connected' if self.anthropic_client else '❌ Disconnected'}
📊 GitHub API: {'✅ Connected' if self.github_client else '❌ Disconnected'}
"""
            await ctx.send(status_msg)
            
        @self.bot.command(name='test')
        async def test(ctx):
            """Test bot functionality"""
            await ctx.send("🧪 Running test...")
            
            # Test GitHub API
            try:
                repo = self.github_client.get_repo(self.target_repo)
                await ctx.send(f"✅ GitHub API working - Repository: {repo.full_name}")
            except Exception as e:
                await ctx.send(f"❌ GitHub API error: {str(e)}")
                
            # Test Anthropic API
            if self.anthropic_client:
                try:
                    response = self.anthropic_client.messages.create(
                        model="claude-3-5-sonnet-20241022",  # ✅ FIXED MODEL NAME
                        max_tokens=50,
                        messages=[{"role": "user", "content": "Hello, please respond with 'API test successful'"}]
                    )
                    await ctx.send(f"✅ Anthropic API working: {response.content[0].text}")
                except Exception as e:
                    await ctx.send(f"❌ Anthropic API error: {str(e)}")
            else:
                await ctx.send("❌ Anthropic API not initialized")
    
    async def handle_push_event(self, payload):
        """Handle GitHub push event"""
        try:
            # Check if the push is from our target repository
            if payload['repository']['full_name'] != self.target_repo:
                logger.info(f"Ignoring push from {payload['repository']['full_name']} (not target repo)")
                return
                
            # Check commits for our target user
            target_commits = []
            for commit in payload.get('commits', []):
                author = commit.get('author', {})
                if author.get('username') == self.target_user:
                    target_commits.append(commit)
                    
            if not target_commits:
                logger.info(f"No commits from target user {self.target_user}")
                return
                
            logger.info(f"Found {len(target_commits)} commits from {self.target_user}")
            
            for commit in target_commits:
                await self.process_commit(commit, payload['repository'])
                # Add delay between commits to avoid rate limiting
                await asyncio.sleep(2)
                    
        except Exception as e:
            logger.error(f"Error handling push event: {e}")
            await self.send_error_notification(f"Error processing push event: {str(e)}")
    
    async def process_commit(self, commit, repo_info):
        """Process a commit from the target user"""
        try:
            logger.info(f"Processing commit: {commit['id']}")
            
            # Get repository object
            repo = self.github_client.get_repo(self.target_repo)
            commit_obj = repo.get_commit(commit['id'])
            
            # Get modified files
            modified_files = []
            for file in commit_obj.files:
                if file.status in ['modified', 'added'] and self.is_code_file(file.filename):
                    try:
                        file_content = repo.get_contents(file.filename, ref=commit['id'])
                        modified_files.append({
                            'filename': file.filename,
                            'content': file_content.decoded_content.decode('utf-8'),
                            'patch': file.patch,
                            'status': file.status
                        })
                    except Exception as e:
                        logger.warning(f"Could not read file {file.filename}: {e}")
            
            if not modified_files:
                logger.info(f"No code files to review in commit {commit['id']}")
                return
                
            logger.info(f"Found {len(modified_files)} files to review")
            
            # Send to Claude for review
            review_result = await self.review_with_claude(modified_files, commit)
            
            # Send to Discord
            await self.send_discord_notification(commit, review_result, modified_files)
            
            # NEW: Create issue for problems
            issue = await self.create_issue_for_problems(commit, review_result, modified_files)
            
            # NEW: Generate improvements and create PR
            if issue:  # Only create PR if there are issues to fix
                improvements = await self.generate_code_improvements(modified_files, review_result)
                if improvements:
                    pr = await self.create_improvement_pull_request(commit, review_result, modified_files, improvements)
                    
                    # Update Discord notification with issue and PR info
                    await self.send_followup_notification(issue, pr)
                
        except Exception as e:
            logger.error(f"Error processing commit: {e}")
            await self.send_error_notification(f"Error processing commit {commit['id']}: {str(e)}")

    async def send_followup_notification(self, issue, pr):
        """Send follow-up notification about created issue/PR"""
        try:
            channel = self.bot.get_channel(self.discord_channel_id)
            if not channel:
                return
                
            embed = discord.Embed(
                title="🔧 Automated Actions Taken",
                color=0x00ff00,
                timestamp=datetime.now()
            )
            
            if issue:
                embed.add_field(
                    name="📋 Issue Created",
                    value=f"[#{issue.number}]({issue.html_url})",
                    inline=True
                )
            
            if pr:
                embed.add_field(
                    name="🔀 Pull Request Created",
                    value=f"[#{pr.number}]({pr.html_url})",
                    inline=True
                )
            
            await channel.send(embed=embed)
            
        except Exception as e:
            logger.error(f"Error sending followup notification: {e}")
    
    def is_code_file(self, filename):
        """Check if file is a code file we should review"""
        code_extensions = [
            '.py', '.js', '.ts', '.jsx', '.tsx', '.java', '.cpp', '.c', '.cs', 
            '.go', '.rs', '.php', '.rb', '.swift', '.kt', '.scala', '.r', '.m',
            '.h', '.hpp', '.css', '.scss', '.sass', '.less', '.html', '.xml',
            '.json', '.yml', '.yaml', '.sql', '.sh', '.bash', '.ps1'
        ]
        return any(filename.endswith(ext) for ext in code_extensions)
    
    async def review_with_claude(self, files, commit):
        """Send code to Claude for review"""
        if not self.anthropic_client:
            return {
                'review': "Anthropic API not available - code review disabled",
                'files_reviewed': len(files),
                'commit_id': commit['id'],
                'error': 'Anthropic API not initialized'
            }
            
        try:
            # Prepare the prompt
            files_content = ""
            for file in files:
                files_content += f"\n\n--- {file['filename']} ({file['status']}) ---\n"
                files_content += file['content'][:5000]  # Limit file content length
                if len(file['content']) > 5000:
                    files_content += "\n... (content truncated) ..."
                    
                if file['patch']:
                    files_content += f"\n\n--- Changes in {file['filename']} ---\n"
                    files_content += file['patch'][:2000]  # Limit patch length
            
            prompt = f"""
Please review the following code files from a recent commit and provide a concise analysis:

**Commit Information:**
- Message: {commit['message']}
- ID: {commit['id']}
- Author: {commit['author']['name']}

**Files to Review:**
{files_content}

**Please provide:**
1. **Critical Issues**: Any bugs, errors, or security vulnerabilities
2. **Code Quality**: Key improvements for readability and maintainability
3. **Best Practices**: Important violations to address
4. **Overall Assessment**: Brief summary of code quality

Keep the response concise and focused on the most important issues.
"""

            # Call Claude API with retry logic
            max_retries = 3
            for attempt in range(max_retries):
                try:
                    response = self.anthropic_client.messages.create(
                        model="claude-3-5-sonnet-20241022",  # ✅ FIXED MODEL NAME
                        max_tokens=2000,
                        messages=[{"role": "user", "content": prompt}]
                    )
                    
                    return {
                        'review': response.content[0].text,
                        'files_reviewed': len(files),
                        'commit_id': commit['id']
                    }
                    
                except Exception as api_error:
                    if attempt < max_retries - 1:
                        logger.warning(f"Claude API attempt {attempt + 1} failed: {api_error}")
                        await asyncio.sleep(2 ** attempt)  # Exponential backoff
                        continue
                    else:
                        raise api_error
            
        except Exception as e:
            logger.error(f"Error calling Claude API: {e}")
            return {
                'review': f"Unable to complete code review due to API error: {str(e)[:200]}...",
                'files_reviewed': len(files),
                'commit_id': commit['id'],
                'error': str(e)
            }
    
    async def create_issue_for_problems(self, commit, review_result, files):
        """Create GitHub issue for identified problems"""
        try:
            repo = self.github_client.get_repo(self.target_repo)
            
            # Extract problems from Claude's review
            problems = self.extract_problems_from_review(review_result['review'])
            
            if not problems:
                logger.info("No significant problems found, skipping issue creation")
                return None
                
            # Create issue title and body
            issue_title = f"Code Review Issues - Commit {commit['id'][:7]}"
            issue_body = f"""
    ## Code Review Issues Found

    **Commit:** [{commit['id'][:7]}]({commit['url']})
    **Author:** {commit['author']['name']}
    **Message:** {commit['message']}

    ### Files Reviewed:
    {', '.join([f'`{f["filename"]}`' for f in files])}

    ### Issues Identified:
    {problems}

    ### Full Review:
    {review_result['review'][:2000]}

    **Auto-generated by Code Review Bot**
    """
            
            # Create the issue
            issue = repo.create_issue(
                title=issue_title,
                body=issue_body,
                labels=['code-review', 'auto-generated']
            )
            
            logger.info(f"Created issue #{issue.number}: {issue.title}")
            return issue
            
        except Exception as e:
            logger.error(f"Error creating issue: {e}")
            return None
    

    def extract_problems_from_review(self, review_text):
        """Extract actionable problems from Claude's review"""
        problems = []
        
        # Simple parsing - look for sections with issues
        lines = review_text.split('\n')
        current_section = ""
        
        for line in lines:
            line = line.strip()
            if any(keyword in line.lower() for keyword in ['critical', 'bug', 'error', 'security', 'issue']):
                problems.append(f"- {line}")
            elif line.startswith('•') or line.startswith('-') or line.startswith('*'):
                if any(keyword in line.lower() for keyword in ['should', 'missing', 'incorrect', 'vulnerable']):
                    problems.append(f"- {line}")
        
        return '\n'.join(problems) if problems else "No critical issues identified."

    async def generate_code_improvements(self, files, review_result):
        """Generate improved code using Claude"""
        if not self.anthropic_client:
            return None
            
        try:
            # Focus on the most critical file or first file
            primary_file = files[0]
            
            prompt = f"""
    Based on the code review, please provide improved versions of the problematic code sections.

    **Original File:** {primary_file['filename']}
    **Review Findings:** {review_result['review'][:1000]}

    **Current Code:**
    {primary_file['content'][:3000]}

    Please provide:
    1. **Specific code improvements** - Show the exact code sections that need changes
    2. **Explanation** - Brief explanation of each improvement
    3. **Fixed code** - The corrected version

    Format your response as:
    ## Issue 1: [Brief description]
    **Problem:** [What's wrong]
    **Solution:** [How to fix]
    **Code:**
    ```python
    [improved code]
    Keep improvements focused and practical.
    """
            response = self.anthropic_client.messages.create(
                model="claude-3-5-sonnet-20241022",
                max_tokens=3000,
                messages=[{"role": "user", "content": prompt}]
            )
            
            return response.content[0].text
            
        except Exception as e:
            logger.error(f"Error generating code improvements: {e}")
            return None

    async def create_improvement_pull_request(self, commit, review_result, files, improvements):
        """Create a pull request with code improvements"""
        try:
            repo = self.github_client.get_repo(self.target_repo)
            # Create a new branch for improvements
            base_branch = repo.default_branch
            new_branch = f"code-review-improvements-{commit['id'][:7]}"
            
            # Get the base branch reference
            base_ref = repo.get_git_ref(f"heads/{base_branch}")
            
            # Create new branch
            repo.create_git_ref(
                ref=f"refs/heads/{new_branch}",
                sha=base_ref.object.sha
            )
            
            # Apply improvements to files
            files_updated = []
            for file_info in files:
                if self.should_update_file(file_info, improvements):
                    improved_content = self.apply_improvements_to_file(
                        file_info['content'], 
                        improvements
                    )
                    
                    if improved_content and improved_content != file_info['content']:
                        # Update file in the new branch
                        file_obj = repo.get_contents(file_info['filename'], ref=new_branch)
                        repo.update_file(
                            file_info['filename'],
                            f"Code review improvements for {file_info['filename']}",
                            improved_content,
                            file_obj.sha,
                            branch=new_branch
                        )
                        files_updated.append(file_info['filename'])
            
            if not files_updated:
                logger.info("No files were updated, skipping PR creation")
                # Clean up branch
                repo.get_git_ref(f"heads/{new_branch}").delete()
                return None
            
            # Create pull request
            pr_title = f"Code Review Improvements - Commit {commit['id'][:7]}"
            pr_body = f"""
        Automated Code Improvements
        This PR contains improvements based on automated code review of commit {commit['id'][:7]}.
        Original Commit: {commit['id'][:7]}
        Author: {commit['author']['name']}
        Files Updated:
        {', '.join([f'{f}' for f in files_updated])}
        Improvements Applied:
        {improvements[:1500]}
        Review Summary:
        {review_result['review'][:1000]}
        ⚠️ Please review these changes carefully before merging
        Auto-generated by Code Review Bot
        """
            pr = repo.create_pull(
                title=pr_title,
                body=pr_body,
                head=new_branch,
                base=base_branch
            )
            
            logger.info(f"Created PR #{pr.number}: {pr.title}")
            return pr
            
        except Exception as e:
            logger.error(f"Error creating pull request: {e}")
            return None

    def should_update_file(self, file_info, improvements):
        """Check if file should be updated based on improvements"""
        # Simple check - if improvements mention the file
        return file_info['filename'] in improvements
    
    def apply_improvements_to_file(self, original_content, improvements):
        """Apply improvements to file content"""
        # This is a simplified approach - in practice, you'd want more sophisticated parsing
        # For now, we'll just return the original content as this requires careful implementation
        # to avoid breaking the code
        # You could implement more sophisticated code replacement here
        # using AST parsing for Python files, etc.

        logger.info("Code improvement application needs manual implementation")
        return original_content
    
    

    async def send_discord_notification(self, commit, review_result, files):
        """Send review results to Discord"""
        try:
            channel = self.bot.get_channel(self.discord_channel_id)
            if not channel:
                logger.error("Discord channel not found")
                return
            
            # Create embed
            embed = discord.Embed(
                title="🔍 Code Review Complete",
                description=f"Reviewed commit by **{self.target_user}**",
                color=0x00ff00 if not review_result.get('error') else 0xff9900,
                timestamp=datetime.now()
            )
            
            # Add commit info
            embed.add_field(
                name="📝 Commit",
                value=f"[`{commit['id'][:7]}`]({commit['url']})",
                inline=True
            )
            
            embed.add_field(
                name="📁 Files",
                value=str(len(files)),
                inline=True
            )
            
            embed.add_field(
                name="👤 Author",
                value=commit['author']['name'],
                inline=True
            )
            
            # Add commit message
            commit_msg = commit['message']
            if len(commit_msg) > 100:
                commit_msg = commit_msg[:100] + "..."
            embed.add_field(
                name="💬 Message",
                value=f"```{commit_msg}```",
                inline=False
            )
            
            # Add file list
            file_list = ", ".join([f"`{f['filename']}`" for f in files[:5]])
            if len(files) > 5:
                file_list += f" and {len(files) - 5} more..."
            embed.add_field(
                name="📄 Modified Files",
                value=file_list,
                inline=False
            )
            
            await channel.send(embed=embed)
            
            # Send review content
            if review_result.get('error'):
                error_embed = discord.Embed(
                    title="⚠️ Review Error",
                    description=review_result['error'],
                    color=0xff0000
                )
                await channel.send(embed=error_embed)
            else:
                review_text = review_result['review']
                
                # Split review into chunks if too long
                if len(review_text) > 2000:
                    chunks = [review_text[i:i+2000] for i in range(0, len(review_text), 2000)]
                    for i, chunk in enumerate(chunks):
                        if i == 0:
                            await channel.send(f"**📋 Code Review Results:**\n```\n{chunk}\n```")
                        else:
                            await channel.send(f"```\n{chunk}\n```")
                else:
                    await channel.send(f"**📋 Code Review Results:**\n```\n{review_text}\n```")
            
        except Exception as e:
            logger.error(f"Error sending Discord notification: {e}")
    
    async def send_error_notification(self, error_message):
        """Send error notification to Discord"""
        try:
            channel = self.bot.get_channel(self.discord_channel_id)
            if channel:
                embed = discord.Embed(
                    title="❌ Bot Error",
                    description=error_message,
                    color=0xff0000,
                    timestamp=datetime.now()
                )
                await channel.send(embed=embed)
        except Exception as e:
            logger.error(f"Error sending error notification: {e}")
    
    def run_webhook_server(self):
        """Run the Flask webhook server"""
        port = int(os.getenv('PORT', 7860))
        logger.info(f"Starting webhook server on port {port}")
        self.app.run(host='0.0.0.0', port=port, debug=False)
    
    def run_discord_bot(self):
        """Run the Discord bot"""
        logger.info("Starting Discord bot...")
        self.bot.run(self.discord_token)
    
    def start(self):
        """Start both the webhook server and Discord bot"""
        logger.info("Starting GitHub Code Review Bot...")
        logger.info(f"Monitoring: {self.target_repo} for user: {self.target_user}")
        
        # Run webhook server in a separate thread
        webhook_thread = threading.Thread(target=self.run_webhook_server)
        webhook_thread.daemon = True
        webhook_thread.start()
        
        # Small delay to ensure webhook server starts
        time.sleep(2)
        
        # Run Discord bot in main thread
        self.run_discord_bot()

if __name__ == "__main__":
    try:
        bot = GitHubCodeReviewBot()
        bot.start()
    except KeyboardInterrupt:
        logger.info("Bot stopped by user")
    except Exception as e:
        logger.error(f"Fatal error: {e}")
        sys.exit(1)