"""
Utility functions for the LightRAG API.
"""

import os
import argparse
from typing import Optional, List, Tuple
import sys
from ascii_colors import ASCIIColors
from lightrag.api import __api_version__ as api_version
from lightrag import __version__ as core_version
from lightrag.constants import (
    DEFAULT_MAX_TOKEN_SUMMARY,
    DEFAULT_FORCE_LLM_SUMMARY_ON_MERGE,
)
from fastapi import HTTPException, Security, Request, status
from fastapi.security import APIKeyHeader, OAuth2PasswordBearer
from starlette.status import HTTP_403_FORBIDDEN
from .auth import auth_handler
from .config import ollama_server_infos, global_args, get_env_value


def check_env_file():
    """
    Check if .env file exists and handle user confirmation if needed.
    Returns True if should continue, False if should exit.
    """
    if not os.path.exists(".env"):
        warning_msg = "Warning: Startup directory must contain .env file for multi-instance support."
        ASCIIColors.yellow(warning_msg)

        # Check if running in interactive terminal
        if sys.stdin.isatty():
            response = input("Do you want to continue? (yes/no): ")
            if response.lower() != "yes":
                ASCIIColors.red("Server startup cancelled")
                return False
    return True


# Get whitelist paths from global_args, only once during initialization
whitelist_paths = global_args.whitelist_paths.split(",")

# Pre-compile path matching patterns
whitelist_patterns: List[Tuple[str, bool]] = []
for path in whitelist_paths:
    path = path.strip()
    if path:
        # If path ends with /*, match all paths with that prefix
        if path.endswith("/*"):
            prefix = path[:-2]
            whitelist_patterns.append((prefix, True))  # (prefix, is_prefix_match)
        else:
            whitelist_patterns.append((path, False))  # (exact_path, is_prefix_match)

# Global authentication configuration
auth_configured = bool(auth_handler.accounts)


def get_combined_auth_dependency(api_key: Optional[str] = None):
    """
    Create a combined authentication dependency that implements authentication logic
    based on API key, OAuth2 token, and whitelist paths.

    Args:
        api_key (Optional[str]): API key for validation

    Returns:
        Callable: A dependency function that implements the authentication logic
    """
    # Use global whitelist_patterns and auth_configured variables
    # whitelist_patterns and auth_configured are already initialized at module level

    # Only calculate api_key_configured as it depends on the function parameter
    api_key_configured = bool(api_key)

    # Create security dependencies with proper descriptions for Swagger UI
    oauth2_scheme = OAuth2PasswordBearer(
        tokenUrl="login", auto_error=False, description="OAuth2 Password Authentication"
    )

    # If API key is configured, create an API key header security
    api_key_header = None
    if api_key_configured:
        api_key_header = APIKeyHeader(
            name="X-API-Key", auto_error=False, description="API Key Authentication"
        )

    async def combined_dependency(
        request: Request,
        token: str = Security(oauth2_scheme),
        api_key_header_value: Optional[str] = None
        if api_key_header is None
        else Security(api_key_header),
    ):
        # 1. Check if path is in whitelist
        path = request.url.path
        for pattern, is_prefix in whitelist_patterns:
            if (is_prefix and path.startswith(pattern)) or (
                not is_prefix and path == pattern
            ):
                return  # Whitelist path, allow access

        # 2. Validate token first if provided in the request (Ensure 401 error if token is invalid)
        if token:
            try:
                token_info = auth_handler.validate_token(token)
                # Accept guest token if no auth is configured
                if not auth_configured and token_info.get("role") == "guest":
                    return
                # Accept non-guest token if auth is configured
                if auth_configured and token_info.get("role") != "guest":
                    return

                # Token validation failed, immediately return 401 error
                raise HTTPException(
                    status_code=status.HTTP_401_UNAUTHORIZED,
                    detail="Invalid token. Please login again.",
                )
            except HTTPException as e:
                # If already a 401 error, re-raise it
                if e.status_code == status.HTTP_401_UNAUTHORIZED:
                    raise
                # For other exceptions, continue processing

        # 3. Acept all request if no API protection needed
        if not auth_configured and not api_key_configured:
            return

        # 4. Validate API key if provided and API-Key authentication is configured
        if (
            api_key_configured
            and api_key_header_value
            and api_key_header_value == api_key
        ):
            return  # API key validation successful

        ### Authentication failed ####

        # if password authentication is configured but not provided, ensure 401 error if auth_configured
        if auth_configured and not token:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="No credentials provided. Please login.",
            )

        # if api key is provided but validation failed
        if api_key_header_value:
            raise HTTPException(
                status_code=HTTP_403_FORBIDDEN,
                detail="Invalid API Key",
            )

        # if api_key_configured but not provided
        if api_key_configured and not api_key_header_value:
            raise HTTPException(
                status_code=HTTP_403_FORBIDDEN,
                detail="API Key required",
            )

        # Otherwise: refuse access and return 403 error
        raise HTTPException(
            status_code=HTTP_403_FORBIDDEN,
            detail="API Key required or login authentication required.",
        )

    return combined_dependency


def display_splash_screen(args: argparse.Namespace) -> None:
    """
    Display a colorful splash screen showing LightRAG server configuration

    Args:
        args: Parsed command line arguments
    """
    # Banner
    ASCIIColors.cyan(f"""
    ╔══════════════════════════════════════════════════════════════╗
    ║                  🚀 LightRAG Server v{core_version}/{api_version}              ║
    ║          Fast, Lightweight RAG Server Implementation         ║
    ╚══════════════════════════════════════════════════════════════╝
    """)

    # Server Configuration
    ASCIIColors.magenta("\n📡 Server Configuration:")
    ASCIIColors.white("    ├─ Host: ", end="")
    ASCIIColors.yellow(f"{args.host}")
    ASCIIColors.white("    ├─ Port: ", end="")
    ASCIIColors.yellow(f"{args.port}")
    ASCIIColors.white("    ├─ Workers: ", end="")
    ASCIIColors.yellow(f"{args.workers}")
    ASCIIColors.white("    ├─ CORS Origins: ", end="")
    ASCIIColors.yellow(f"{args.cors_origins}")
    ASCIIColors.white("    ├─ SSL Enabled: ", end="")
    ASCIIColors.yellow(f"{args.ssl}")
    if args.ssl:
        ASCIIColors.white("    ├─ SSL Cert: ", end="")
        ASCIIColors.yellow(f"{args.ssl_certfile}")
        ASCIIColors.white("    ├─ SSL Key: ", end="")
        ASCIIColors.yellow(f"{args.ssl_keyfile}")
    ASCIIColors.white("    ├─ Ollama Emulating Model: ", end="")
    ASCIIColors.yellow(f"{ollama_server_infos.LIGHTRAG_MODEL}")
    ASCIIColors.white("    ├─ Log Level: ", end="")
    ASCIIColors.yellow(f"{args.log_level}")
    ASCIIColors.white("    ├─ Verbose Debug: ", end="")
    ASCIIColors.yellow(f"{args.verbose}")
    ASCIIColors.white("    ├─ History Turns: ", end="")
    ASCIIColors.yellow(f"{args.history_turns}")
    ASCIIColors.white("    ├─ API Key: ", end="")
    ASCIIColors.yellow("Set" if args.key else "Not Set")
    ASCIIColors.white("    └─ JWT Auth: ", end="")
    ASCIIColors.yellow("Enabled" if args.auth_accounts else "Disabled")

    # Directory Configuration
    ASCIIColors.magenta("\n📂 Directory Configuration:")
    ASCIIColors.white("    ├─ Working Directory: ", end="")
    ASCIIColors.yellow(f"{args.working_dir}")
    ASCIIColors.white("    └─ Input Directory: ", end="")
    ASCIIColors.yellow(f"{args.input_dir}")

    # LLM Configuration
    ASCIIColors.magenta("\n🤖 LLM Configuration:")
    ASCIIColors.white("    ├─ Binding: ", end="")
    ASCIIColors.yellow(f"{args.llm_binding}")
    ASCIIColors.white("    ├─ Host: ", end="")
    ASCIIColors.yellow(f"{args.llm_binding_host}")
    ASCIIColors.white("    ├─ Model: ", end="")
    ASCIIColors.yellow(f"{args.llm_model}")
    ASCIIColors.white("    ├─ Temperature: ", end="")
    ASCIIColors.yellow(f"{args.temperature}")
    ASCIIColors.white("    ├─ Max Async for LLM: ", end="")
    ASCIIColors.yellow(f"{args.max_async}")
    ASCIIColors.white("    ├─ Max Tokens: ", end="")
    ASCIIColors.yellow(f"{args.max_tokens}")
    ASCIIColors.white("    ├─ Timeout: ", end="")
    ASCIIColors.yellow(f"{args.timeout if args.timeout else 'None (infinite)'}")
    ASCIIColors.white("    ├─ LLM Cache Enabled: ", end="")
    ASCIIColors.yellow(f"{args.enable_llm_cache}")
    ASCIIColors.white("    └─ LLM Cache for Extraction Enabled: ", end="")
    ASCIIColors.yellow(f"{args.enable_llm_cache_for_extract}")

    # Embedding Configuration
    ASCIIColors.magenta("\n📊 Embedding Configuration:")
    ASCIIColors.white("    ├─ Binding: ", end="")
    ASCIIColors.yellow(f"{args.embedding_binding}")
    ASCIIColors.white("    ├─ Host: ", end="")
    ASCIIColors.yellow(f"{args.embedding_binding_host}")
    ASCIIColors.white("    ├─ Model: ", end="")
    ASCIIColors.yellow(f"{args.embedding_model}")
    ASCIIColors.white("    └─ Dimensions: ", end="")
    ASCIIColors.yellow(f"{args.embedding_dim}")

    # RAG Configuration
    ASCIIColors.magenta("\n⚙️ RAG Configuration:")
    ASCIIColors.white("    ├─ Summary Language: ", end="")
    ASCIIColors.yellow(f"{args.summary_language}")
    ASCIIColors.white("    ├─ Max Parallel Insert: ", end="")
    ASCIIColors.yellow(f"{args.max_parallel_insert}")
    ASCIIColors.white("    ├─ Max Embed Tokens: ", end="")
    ASCIIColors.yellow(f"{args.max_embed_tokens}")
    ASCIIColors.white("    ├─ Chunk Size: ", end="")
    ASCIIColors.yellow(f"{args.chunk_size}")
    ASCIIColors.white("    ├─ Chunk Overlap Size: ", end="")
    ASCIIColors.yellow(f"{args.chunk_overlap_size}")
    ASCIIColors.white("    ├─ Cosine Threshold: ", end="")
    ASCIIColors.yellow(f"{args.cosine_threshold}")
    ASCIIColors.white("    ├─ Top-K: ", end="")
    ASCIIColors.yellow(f"{args.top_k}")
    ASCIIColors.white("    ├─ Max Token Summary: ", end="")
    ASCIIColors.yellow(
        f"{get_env_value('MAX_TOKEN_SUMMARY', DEFAULT_MAX_TOKEN_SUMMARY, int)}"
    )
    ASCIIColors.white("    └─ Force LLM Summary on Merge: ", end="")
    ASCIIColors.yellow(
        f"{get_env_value('FORCE_LLM_SUMMARY_ON_MERGE', DEFAULT_FORCE_LLM_SUMMARY_ON_MERGE, int)}"
    )

    # System Configuration
    ASCIIColors.magenta("\n💾 Storage Configuration:")
    ASCIIColors.white("    ├─ KV Storage: ", end="")
    ASCIIColors.yellow(f"{args.kv_storage}")
    ASCIIColors.white("    ├─ Vector Storage: ", end="")
    ASCIIColors.yellow(f"{args.vector_storage}")
    ASCIIColors.white("    ├─ Graph Storage: ", end="")
    ASCIIColors.yellow(f"{args.graph_storage}")
    ASCIIColors.white("    └─ Document Status Storage: ", end="")
    ASCIIColors.yellow(f"{args.doc_status_storage}")

    # Server Status
    ASCIIColors.green("\n✨ Server starting up...\n")

    # Server Access Information
    protocol = "https" if args.ssl else "http"
    if args.host == "0.0.0.0":
        ASCIIColors.magenta("\n🌐 Server Access Information:")
        ASCIIColors.white("    ├─ WebUI (local): ", end="")
        ASCIIColors.yellow(f"{protocol}://localhost:{args.port}")
        ASCIIColors.white("    ├─ Remote Access: ", end="")
        ASCIIColors.yellow(f"{protocol}://<your-ip-address>:{args.port}")
        ASCIIColors.white("    ├─ API Documentation (local): ", end="")
        ASCIIColors.yellow(f"{protocol}://localhost:{args.port}/docs")
        ASCIIColors.white("    └─ Alternative Documentation (local): ", end="")
        ASCIIColors.yellow(f"{protocol}://localhost:{args.port}/redoc")

        ASCIIColors.magenta("\n📝 Note:")
        ASCIIColors.cyan("""    Since the server is running on 0.0.0.0:
    - Use 'localhost' or '127.0.0.1' for local access
    - Use your machine's IP address for remote access
    - To find your IP address:
      • Windows: Run 'ipconfig' in terminal
      • Linux/Mac: Run 'ifconfig' or 'ip addr' in terminal
    """)
    else:
        base_url = f"{protocol}://{args.host}:{args.port}"
        ASCIIColors.magenta("\n🌐 Server Access Information:")
        ASCIIColors.white("    ├─ WebUI (local): ", end="")
        ASCIIColors.yellow(f"{base_url}")
        ASCIIColors.white("    ├─ API Documentation: ", end="")
        ASCIIColors.yellow(f"{base_url}/docs")
        ASCIIColors.white("    └─ Alternative Documentation: ", end="")
        ASCIIColors.yellow(f"{base_url}/redoc")

    # Security Notice
    if args.key:
        ASCIIColors.yellow("\n⚠️  Security Notice:")
        ASCIIColors.white("""    API Key authentication is enabled.
    Make sure to include the X-API-Key header in all your requests.
    """)
    if args.auth_accounts:
        ASCIIColors.yellow("\n⚠️  Security Notice:")
        ASCIIColors.white("""    JWT authentication is enabled.
    Make sure to login before making the request, and include the 'Authorization' in the header.
    """)

    # Ensure splash output flush to system log
    sys.stdout.flush()
