"""
capture.py — Quick log entries and file uploads to the vault.
"""

from __future__ import annotations

import os
import re
import logging
from datetime import datetime, timezone
from pathlib import Path
from typing import Optional

from fastapi import APIRouter, HTTPException, UploadFile, File, Form
from pydantic import BaseModel

router = APIRouter(tags=['capture'])
logger = logging.getLogger(__name__)

# Vault path from environment
VAULT_PATH = Path(os.getenv('VAULT_PATH', '/vault'))


class LogEntry(BaseModel):
    """Quick log/note entry."""
    content: str
    tags: Optional[list[str]] = None
    title: Optional[str] = None


class LogResponse(BaseModel):
    """Response after creating a log entry."""
    success: bool
    file_path: str
    timestamp: str
    message: str


class UploadResponse(BaseModel):
    """Response after file upload."""
    success: bool
    file_path: str
    filename: str
    size_bytes: int
    message: str


def sanitize_filename(name: str) -> str:
    """Remove unsafe characters from filename."""
    # Keep alphanumeric, dots, dashes, underscores
    safe = re.sub(r'[^\w\-.]', '_', name)
    return safe[:200]  # Limit length


@router.post('/capture/log', response_model=LogResponse)
async def create_log_entry(entry: LogEntry):
    """
    Create a quick log entry. Entries are appended to daily log files
    in the logs/ directory with automatic timestamps.
    """
    now = datetime.now(timezone.utc)
    date_str = now.strftime('%Y-%m-%d')
    time_str = now.strftime('%H:%M:%S')
    
    logs_dir = VAULT_PATH / 'logs'
    logs_dir.mkdir(parents=True, exist_ok=True)
    
    log_file = logs_dir / f'{date_str}.md'
    
    # Format the entry
    lines = []
    
    # If file doesn't exist, add header
    if not log_file.exists():
        lines.append(f'# Log — {date_str}\n\n')
    
    # Entry header with timestamp
    lines.append(f'## {time_str} UTC')
    if entry.title:
        lines.append(f' — {entry.title}')
    lines.append('\n\n')
    
    # Tags
    if entry.tags:
        tag_str = ' '.join(f'#{tag}' for tag in entry.tags)
        lines.append(f'{tag_str}\n\n')
    
    # Content
    lines.append(entry.content.strip())
    lines.append('\n\n---\n\n')
    
    content = ''.join(lines)
    
    try:
        with open(log_file, 'a', encoding='utf-8') as f:
            f.write(content)
        
        logger.info('Log entry created: %s', log_file)
        
        return LogResponse(
            success=True,
            file_path=str(log_file.relative_to(VAULT_PATH)),
            timestamp=now.isoformat(),
            message=f'Log entry added to {date_str}.md'
        )
    except Exception as e:
        logger.error('Failed to write log: %s', e)
        raise HTTPException(status_code=500, detail=f'Failed to write log: {e}')


@router.post('/capture/upload', response_model=UploadResponse)
async def upload_document(
    file: UploadFile = File(...),
    folder: str = Form(default='uploads'),
    tags: Optional[str] = Form(default=None),
):
    """
    Upload a document to the vault. Supports markdown, text, and PDF files.
    
    - folder: Subfolder in vault (default: uploads)
    - tags: Comma-separated tags to add as frontmatter (for .md files)
    """
    if not file.filename:
        raise HTTPException(status_code=400, detail='No filename provided')
    
    # Sanitize inputs
    safe_folder = sanitize_filename(folder)
    safe_filename = sanitize_filename(file.filename)
    
    # Allowed extensions
    allowed_ext = {'.md', '.txt', '.pdf', '.json', '.yaml', '.yml', '.csv'}
    ext = Path(safe_filename).suffix.lower()
    
    if ext not in allowed_ext:
        raise HTTPException(
            status_code=400, 
            detail=f'File type {ext} not allowed. Allowed: {", ".join(allowed_ext)}'
        )
    
    # Target directory
    target_dir = VAULT_PATH / safe_folder
    target_dir.mkdir(parents=True, exist_ok=True)
    
    target_path = target_dir / safe_filename
    
    # Handle duplicates by adding timestamp
    if target_path.exists():
        stem = Path(safe_filename).stem
        timestamp = datetime.now().strftime('%Y%m%d_%H%M%S')
        safe_filename = f'{stem}_{timestamp}{ext}'
        target_path = target_dir / safe_filename
    
    try:
        content = await file.read()
        
        # If markdown and tags provided, prepend frontmatter
        if ext == '.md' and tags:
            tag_list = [t.strip() for t in tags.split(',') if t.strip()]
            if tag_list:
                frontmatter = '---\n'
                frontmatter += f'tags: [{", ".join(tag_list)}]\n'
                frontmatter += f'uploaded: {datetime.now(timezone.utc).isoformat()}\n'
                frontmatter += '---\n\n'
                content = frontmatter.encode('utf-8') + content
        
        with open(target_path, 'wb') as f:
            f.write(content)
        
        logger.info('File uploaded: %s (%d bytes)', target_path, len(content))
        
        return UploadResponse(
            success=True,
            file_path=str(target_path.relative_to(VAULT_PATH)),
            filename=safe_filename,
            size_bytes=len(content),
            message=f'File uploaded to {safe_folder}/'
        )
    except Exception as e:
        logger.error('Upload failed: %s', e)
        raise HTTPException(status_code=500, detail=f'Upload failed: {e}')


@router.get('/capture/logs')
async def list_logs(limit: int = 10):
    """List recent log files."""
    logs_dir = VAULT_PATH / 'logs'
    
    if not logs_dir.exists():
        return {'logs': [], 'total': 0}
    
    log_files = sorted(logs_dir.glob('*.md'), reverse=True)[:limit]
    
    logs = []
    for lf in log_files:
        stat = lf.stat()
        logs.append({
            'date': lf.stem,
            'file_path': str(lf.relative_to(VAULT_PATH)),
            'size_bytes': stat.st_size,
            'modified': datetime.fromtimestamp(stat.st_mtime, tz=timezone.utc).isoformat()
        })
    
    return {'logs': logs, 'total': len(logs)}


@router.get('/capture/log/{date}')
async def get_log(date: str):
    """Get contents of a specific log file by date (YYYY-MM-DD)."""
    # Validate date format
    if not re.match(r'^\d{4}-\d{2}-\d{2}$', date):
        raise HTTPException(status_code=400, detail='Invalid date format. Use YYYY-MM-DD')
    
    log_file = VAULT_PATH / 'logs' / f'{date}.md'
    
    if not log_file.exists():
        raise HTTPException(status_code=404, detail=f'No log found for {date}')
    
    content = log_file.read_text(encoding='utf-8')
    
    return {
        'date': date,
        'file_path': str(log_file.relative_to(VAULT_PATH)),
        'content': content
    }