import discord
from discord import app_commands
from discord.ext import commands
from discord.ext.commands import Context
import aiohttp
import re
import json


def codepreview_command():
    LANGUAGE_MAP = {
        '.py': 'python',
        '.js': 'js',
        '.ts': 'ts',
        '.java': 'java',
        '.cpp': 'cpp',
        '.c': 'c',
        '.cs': 'cs',
        '.go': 'go',
        '.rs': 'rust',
        '.rb': 'ruby',
        '.php': 'php',
        '.html': 'html',
        '.css': 'css',
        '.json': 'json',
        '.xml': 'xml',
        '.yaml': 'yaml',
        '.yml': 'yaml',
        '.ini': 'ini',
        '.toml': 'toml',
        '.lua': 'lua',
        '.sh': 'bash',
        '.md': 'markdown',
        '.sql': 'sql',
        '.diff': 'diff',
        '.txt': '',
    }

    async def send_embed(context, embed: discord.Embed, *, ephemeral: bool = False) -> None:
        interaction = getattr(context, "interaction", None)
        if interaction is not None:
            if interaction.response.is_done():
                await interaction.followup.send(embed=embed, ephemeral=ephemeral)
            else:
                await interaction.response.send_message(embed=embed, ephemeral=ephemeral)
        else:
            await context.send(embed=embed)

    def get_language_from_filename(filename):
        for ext, lang in LANGUAGE_MAP.items():
            if filename.endswith(ext):
                return lang
        return ''

    async def fetch_github_content(url):
        try:
            async with aiohttp.ClientSession() as session:
                async with session.get(url) as response:
                    if response.status == 200:
                        return await response.text()
        except Exception:
            pass
        return None

    async def fetch_pr_diff(owner, repo, pr_number):
        try:
            api_url = f'https://api.github.com/repos/{owner}/{repo}/pulls/{pr_number}'
            headers = {
                'Accept': 'application/vnd.github.v3.diff',
                'User-Agent': 'Discord-Bot'
            }
            
            async with aiohttp.ClientSession() as session:
                async with session.get(api_url, headers=headers) as response:
                    if response.status == 200:
                        diff_content = await response.text()
                        return diff_content
        except Exception:
            pass
        return None

    async def fetch_pr_info(owner, repo, pr_number):
        try:
            api_url = f'https://api.github.com/repos/{owner}/{repo}/pulls/{pr_number}'
            headers = {
                'Accept': 'application/vnd.github.v3+json',
                'User-Agent': 'Discord-Bot'
            }
            
            async with aiohttp.ClientSession() as session:
                async with session.get(api_url, headers=headers) as response:
                    if response.status == 200:
                        pr_data = await response.json()
                        return {
                            'title': pr_data.get('title', ''),
                            'number': pr_data.get('number', pr_number),
                            'state': pr_data.get('state', ''),
                            'merged': pr_data.get('merged', False),
                            'additions': pr_data.get('additions', 0),
                            'deletions': pr_data.get('deletions', 0),
                            'changed_files': pr_data.get('changed_files', 0),
                            'user': pr_data.get('user', {}).get('login', ''),
                            'base_branch': pr_data.get('base', {}).get('ref', ''),
                            'head_branch': pr_data.get('head', {}).get('ref', '')
                        }
        except Exception:
            pass
        return None

    def parse_github_url(url):
        pr_pattern = r'https://github\.com/([^/]+)/([^/]+)/pull/(\d+)(?:/files)?'
        pr_match = re.match(pr_pattern, url)
        
        if pr_match:
            owner, repo, pr_number = pr_match.groups()
            return {
                'type': 'pr',
                'owner': owner,
                'repo': repo,
                'pr_number': pr_number
            }
        
        raw_pattern = r'https://raw\.githubusercontent\.com/([^/]+)/([^/]+)/([^/]+)/(.+?)$'
        raw_match = re.match(raw_pattern, url)
        
        if raw_match:
            owner, repo, branch, filepath = raw_match.groups()
            
            return {
                'type': 'file',
                'owner': owner,
                'repo': repo,
                'branch': branch,
                'filepath': filepath,
                'raw_url': url,
                'start_line': None,
                'end_line': None
            }
        
        pattern = r'https://github\.com/([^/]+)/([^/]+)/blob/([^/]+)/(.+?)(?:#L(\d+)(?:-L(\d+))?)?$'
        match = re.match(pattern, url)
        
        if match:
            owner, repo, branch, filepath, start_line, end_line = match.groups()
            
            raw_url = f'https://raw.githubusercontent.com/{owner}/{repo}/{branch}/{filepath}'
            
            return {
                'type': 'file',
                'owner': owner,
                'repo': repo,
                'branch': branch,
                'filepath': filepath,
                'raw_url': raw_url,
                'start_line': int(start_line) if start_line else None,
                'end_line': int(end_line) if end_line else None
            }
        return None

    def extract_lines(content, start_line, end_line):
        lines = content.split('\n')
        
        if start_line and end_line:
            return '\n'.join(lines[start_line-1:end_line])
        elif start_line:
            return lines[start_line-1] if start_line <= len(lines) else content
        return content

    @commands.hybrid_command(
        name="codepreview",
        description="Preview code from GitHub URLs",
    )
    @app_commands.describe(
        url="GitHub URL to preview code from"
    )
    async def codepreview(self, context, url: str = None):
        if not url or not url.strip():
            if context.message and context.message.reference and context.message.reference.resolved:
                replied_message = context.message.reference.resolved
                if hasattr(replied_message, 'content') and replied_message.content:
                    github_pattern = r'https://(?:github\.com|raw\.githubusercontent\.com)/[^\s]+'
                    urls = re.findall(github_pattern, replied_message.content)
                    if urls:
                        url = urls[0]
                    else:
                        embed = discord.Embed(
                            title="Error",
                            description="No GitHub URL found in the replied message.",
                            color=0xE02B2B,
                        ).set_author(name="Utility", icon_url="https://yes.nighty.works/raw/8VLDcg.webp")
                        await send_embed(context, embed, ephemeral=True)
                        return
                else:
                    embed = discord.Embed(
                        title="Error",
                        description="The replied message has no content to extract GitHub URL from.",
                        color=0xE02B2B,
                    ).set_author(name="Utility", icon_url="https://yes.nighty.works/raw/8VLDcg.webp")
                    await send_embed(context, embed, ephemeral=True)
                    return
            else:
                embed = discord.Embed(
                    title="Error",
                    description="Please provide a GitHub URL or reply to a message containing a GitHub URL.",
                    color=0xE02B2B,
                ).set_author(name="Utility", icon_url="https://yes.nighty.works/raw/8VLDcg.webp")
                await send_embed(context, embed, ephemeral=True)
                return
        
        if not url.startswith('https://github.com/') and not url.startswith('https://raw.githubusercontent.com/'):
            embed = discord.Embed(
                title="Error",
                description="Please provide a valid GitHub URL.",
                color=0xE02B2B,
            ).set_author(name="Utility", icon_url="https://yes.nighty.works/raw/8VLDcg.webp")
            await send_embed(context, embed, ephemeral=True)
            return
        
        parsed = parse_github_url(url)
        
        if not parsed:
            embed = discord.Embed(
                title="Error",
                description="Invalid GitHub URL format. Please provide a valid GitHub blob URL or PR URL.",
                color=0xE02B2B,
            ).set_author(name="Utility", icon_url="https://yes.nighty.works/raw/8VLDcg.webp")
            await send_embed(context, embed, ephemeral=True)
            return
        
        if parsed.get('type') == 'pr':
            pr_info = await fetch_pr_info(parsed['owner'], parsed['repo'], parsed['pr_number'])
            diff_content = await fetch_pr_diff(parsed['owner'], parsed['repo'], parsed['pr_number'])
            
            if not pr_info or not diff_content:
                embed = discord.Embed(
                    title="Error",
                    description="Failed to fetch pull request information. The PR might not exist or be accessible.",
                    color=0xE02B2B,
                ).set_author(name="Utility", icon_url="https://yes.nighty.works/raw/8VLDcg.webp")
                await send_embed(context, embed, ephemeral=True)
                return
            
            pr_url = f"https://github.com/{parsed['owner']}/{parsed['repo']}/pull/{parsed['pr_number']}"
            
            if pr_info['merged']:
                pr_color = 0x6f42c1
                pr_status = "Merged"
            elif pr_info['state'] == 'open':
                pr_color = 0x57F287
                pr_status = "Open"
            else:
                pr_color = 0xE02B2B
                pr_status = "Closed"
            
            embed = discord.Embed(
                title=f"Pull Request #{pr_info['number']}: {pr_info['title'][:100]}",
                description=f"**Repository:** [{parsed['owner']}/{parsed['repo']}]({pr_url})\n**Author:** {pr_info['user']}\n**Status:** {pr_status}",
                color=pr_color,
            )
            embed.set_author(name="Utility", icon_url="https://yes.nighty.works/raw/8VLDcg.webp")
            embed.add_field(name="Changes", value=f"**+{pr_info['additions']}** / **-{pr_info['deletions']}**", inline=True)
            embed.add_field(name="Files Changed", value=f"{pr_info['changed_files']}", inline=True)
            embed.add_field(name="Branches", value=f"`{pr_info['base_branch']}` ← `{pr_info['head_branch']}`", inline=False)
            embed.set_footer(text=f"Requested by {context.author.name}", icon_url=context.author.display_avatar.url)
            
            interaction = getattr(context, "interaction", None)
            if interaction is not None and not interaction.response.is_done():
                await interaction.response.defer(ephemeral=True)
            
            await context.channel.send(embed=embed)
            
            max_diff_length = 1900
            max_lines = 100
            
            diff_lines = diff_content.split('\n')
            
            if len(diff_lines) > max_lines:
                diff_lines = diff_lines[:max_lines]
                diff_lines.append(f"\n... ({len(diff_content.split(chr(10))) - max_lines} more lines omitted)")
            
            current_chunk = ""
            
            for line in diff_lines:
                test_chunk = current_chunk + line + '\n'
                
                if len(test_chunk) + 10 > max_diff_length:
                    if current_chunk.strip():
                        remaining_lines = len(diff_lines) - len(current_chunk.split('\n'))
                        if remaining_lines > 0:
                            current_chunk += f"\n... ({remaining_lines} more lines omitted)"
                        await context.channel.send(f"```diff\n{current_chunk.rstrip()}\n```")
                    break
                else:
                    current_chunk = test_chunk
            else:
                if current_chunk.strip():
                    await context.channel.send(f"```diff\n{current_chunk.rstrip()}\n```")
            
            if interaction is not None:
                try:
                    await interaction.delete_original_response()
                except:
                    pass
            return
        
        content = await fetch_github_content(parsed['raw_url'])
        
        if not content:
            embed = discord.Embed(
                title="Error",
                description="Failed to fetch content from GitHub. The file might not exist or be accessible.",
                color=0xE02B2B,
            ).set_author(name="Utility", icon_url="https://yes.nighty.works/raw/8VLDcg.webp")
            await send_embed(context, embed, ephemeral=True)
            return
        
        if parsed['start_line']:
            code = extract_lines(content, parsed['start_line'], parsed['end_line'])
            line_info = f" (Lines {parsed['start_line']}"
            if parsed['end_line']:
                line_info += f"-{parsed['end_line']}"
            line_info += ")"
        else:
            code = content
            line_info = ""
        
        code_lines = code.split('\n')
        if len(code_lines) > 100:
            code = '\n'.join(code_lines[:100])
            code += f"\n\n... ({len(code_lines) - 100} more lines omitted)"
        
        filename = parsed['filepath'].split('/')[-1]
        language = get_language_from_filename(filename)
        
        embed = discord.Embed(
            title="Code Preview",
            description=f"**Repository URL:** [{parsed['owner']}/{parsed['repo']}]({url})",
            color=0x7289DA,
        )
        embed.set_author(name="Utility", icon_url="https://yes.nighty.works/raw/8VLDcg.webp")
        embed.add_field(name="File", value=f"`{parsed['filepath']}`{line_info}", inline=True)
        embed.add_field(name="Branch", value=f"`{parsed['branch']}`", inline=True)
        embed.set_footer(text=f"Requested by {context.author.name}", icon_url=context.author.display_avatar.url)
        
        code_block = f"```{language}\n{code}\n```"
        
        if len(code_block) > 1990:
            interaction = getattr(context, "interaction", None)
            if interaction is not None:
                if not interaction.response.is_done():
                    await interaction.response.defer(ephemeral=True)
                await context.channel.send(embed=embed)
            else:
                await context.channel.send(embed=embed)
            
            max_code_length = 1980 - len(language) - 8
            code_lines = code.split('\n')
            current_chunk = []
            current_length = 0
            
            for line in code_lines:
                line_length = len(line) + 1
                if current_length + line_length > max_code_length:
                    remaining_lines = len(code_lines) - len(current_chunk)
                    if remaining_lines > 0:
                        current_chunk.append(f"\n... ({remaining_lines} more lines omitted)")
                    chunk_text = '\n'.join(current_chunk)
                    await context.channel.send(f"```{language}\n{chunk_text}\n```")
                    break
                else:
                    current_chunk.append(line)
                    current_length += line_length
            else:
                if current_chunk:
                    chunk_text = '\n'.join(current_chunk)
                    await context.channel.send(f"```{language}\n{chunk_text}\n```")
            
            if interaction is not None:
                try:
                    await interaction.delete_original_response()
                except:
                    pass
        else:
            interaction = getattr(context, "interaction", None)
            if interaction is not None:
                if not interaction.response.is_done():
                    await interaction.response.defer(ephemeral=True)
                await context.channel.send(embed=embed)
                await context.channel.send(code_block)
                try:
                    await interaction.delete_original_response()
                except:
                    pass
            else:
                await context.channel.send(embed=embed)
                await context.channel.send(code_block)

    return codepreview