# interfaces/api/dependencies.py
"""FastAPI dependency injection configuration."""
from typing import Annotated, Optional
from fastapi import Depends, UploadFile, Form, HTTPException, Request, Header
from pydantic import BaseModel, Field, validator
import re

from application.use_cases.container import UseCaseContainer
from infrastructure.services.container import ServiceContainer
from infrastructure.services.jwt_validation_service import JWTValidationService

class ExtractionRequest(BaseModel):
    """Request model for audio extraction."""
    output_format: str = Field(default="mp3", description="Output audio format")
    quality: str = Field(default="medium", description="Audio quality level")
    
    @validator('output_format')
    def validate_format(cls, v):
        allowed = ['mp3', 'aac', 'wav', 'flac', 'm4a', 'ogg']
        if v.lower() not in allowed:
            raise ValueError(f"Format must be one of: {', '.join(allowed)}")
        return v.lower()
    
    @validator('quality')
    def validate_quality(cls, v):
        allowed = ['high', 'medium', 'low']
        if v.lower() not in allowed:
            raise ValueError(f"Quality must be one of: {', '.join(allowed)}")
        return v.lower()

def extraction_params(
    output_format: str = Form("mp3"),
    quality: str = Form("medium")
) -> ExtractionRequest:
    """Parse and validate extraction parameters."""
    return ExtractionRequest(output_format=output_format, quality=quality)

async def validate_video_file(video: UploadFile) -> UploadFile:
    """Validate uploaded video file."""
    if not video.filename:
        raise HTTPException(400, "No filename provided")
    
    # Check file extension
    allowed_extensions = ['.mp4', '.avi', '.mov', '.mkv', '.webm', '.flv', '.wmv', '.m4v']
    file_ext = '.' + video.filename.lower().split('.')[-1] if '.' in video.filename else ''
    
    if file_ext not in allowed_extensions:
        raise HTTPException(
            400, 
            f"Unsupported video format. Allowed: {', '.join(allowed_extensions)}"
        )
    
    # Check content type (basic validation)
    if video.content_type and not video.content_type.startswith(('video/', 'application/octet-stream')):
        raise HTTPException(400, "File must be a video")
    
    return video

async def validate_bearer_token(
    authorization: Optional[str] = Header(None, description="Bearer token for authentication")
) -> str:
    """
    Extract and validate bearer token from Authorization header.
    
    Args:
        authorization: Authorization header value
        
    Returns:
        str: The validated bearer token
        
    Raises:
        HTTPException: 401 if token is missing or invalid
    """
    if not authorization:
        raise HTTPException(
            status_code=401,
            detail="Missing Authorization header",
            headers={"WWW-Authenticate": "Bearer"}
        )
    
    # Check if it starts with "Bearer "
    if not authorization.startswith("Bearer "):
        raise HTTPException(
            status_code=401,
            detail="Invalid Authorization header format. Expected: Bearer <token>",
            headers={"WWW-Authenticate": "Bearer"}
        )
    
    # Extract token
    token = authorization[7:]  # Remove "Bearer " prefix
    if not token:
        raise HTTPException(
            status_code=401,
            detail="Empty bearer token",
            headers={"WWW-Authenticate": "Bearer"}
        )
    
    # Validate JWT structure
    jwt_service = JWTValidationService()
    if not jwt_service.validate_structure(token):
        raise HTTPException(
            status_code=401,
            detail="Invalid JWT token structure",
            headers={"WWW-Authenticate": "Bearer"}
        )
    
    return token

def get_services(request: Request) -> ServiceContainer:
    """Get service container from app state."""
    return request.app.state.get_services()

def get_use_cases(request: Request) -> UseCaseContainer:
    """Get use case container from app state."""
    return request.app.state.get_use_cases()

# Type aliases for dependency injection
ValidatedVideo = Annotated[UploadFile, Depends(validate_video_file)]
ExtractionParams = Annotated[ExtractionRequest, Depends(extraction_params)]
Services = Annotated[ServiceContainer, Depends(get_services)]
UseCases = Annotated[UseCaseContainer, Depends(get_use_cases)]
BearerToken = Annotated[str, Depends(validate_bearer_token)]