import json
from datetime import datetime, UTC, timedelta
from pathlib import Path
import sys
from typing import Any, Dict, List, Optional
from core.models.completion import CompletionResponse
from fastapi import FastAPI, Form, HTTPException, Depends, Header, UploadFile
from fastapi.middleware.cors import CORSMiddleware
import jwt
import logging
from opentelemetry.instrumentation.fastapi import FastAPIInstrumentor
from core.completion.openai_completion import OpenAICompletionModel
from core.embedding.ollama_embedding_model import OllamaEmbeddingModel
from core.models.request import RetrieveRequest, CompletionQueryRequest, IngestTextRequest
from core.models.documents import Document, DocumentResult, ChunkResult
from core.models.auth import AuthContext, EntityType
from core.parser.databridge_parser import DatabridgeParser
from core.services.document_service import DocumentService
from core.services.telemetry import TelemetryService
from core.config import get_settings
from core.database.mongo_database import MongoDatabase
from core.database.postgres_database import PostgresDatabase
from core.vector_store.mongo_vector_store import MongoDBAtlasVectorStore
from core.vector_store.multi_vector_store import MultiVectorStore
from core.embedding.colpali_embedding_model import ColpaliEmbeddingModel
from core.storage.s3_storage import S3Storage
from core.storage.local_storage import LocalStorage
from core.embedding.openai_embedding_model import OpenAIEmbeddingModel
from core.completion.ollama_completion import OllamaCompletionModel
from core.reranker.flag_reranker import FlagReranker
from core.cache.llama_cache_factory import LlamaCacheFactory
import tomli

# Initialize FastAPI app
app = FastAPI(title="DataBridge API")
logger = logging.getLogger(__name__)


# Add health check endpoints
@app.get("/health")
async def health_check():
    """Basic health check endpoint."""
    return {"status": "healthy"}


@app.get("/health/ready")
async def readiness_check():
    """Readiness check that verifies the application is initialized."""
    return {
        "status": "ready",
        "components": {
            "database": settings.DATABASE_PROVIDER,
            "vector_store": settings.VECTOR_STORE_PROVIDER,
            "embedding": settings.EMBEDDING_PROVIDER,
            "completion": settings.COMPLETION_PROVIDER,
            "storage": settings.STORAGE_PROVIDER,
        },
    }


# Initialize telemetry
telemetry = TelemetryService()

# Add OpenTelemetry instrumentation
FastAPIInstrumentor.instrument_app(app)

# Add CORS middleware
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Initialize service
settings = get_settings()

# Initialize database
match settings.DATABASE_PROVIDER:
    case "postgres":
        if not settings.POSTGRES_URI:
            raise ValueError("PostgreSQL URI is required for PostgreSQL database")
        database = PostgresDatabase(uri=settings.POSTGRES_URI)
    case "mongodb":
        if not settings.MONGODB_URI:
            raise ValueError("MongoDB URI is required for MongoDB database")
        database = MongoDatabase(
            uri=settings.MONGODB_URI,
            db_name=settings.DATABRIDGE_DB,
            collection_name=settings.DOCUMENTS_COLLECTION,
        )
    case _:
        raise ValueError(f"Unsupported database provider: {settings.DATABASE_PROVIDER}")

# Initialize vector store
match settings.VECTOR_STORE_PROVIDER:
    case "mongodb":
        vector_store = MongoDBAtlasVectorStore(
            uri=settings.MONGODB_URI,
            database_name=settings.DATABRIDGE_DB,
            collection_name=settings.CHUNKS_COLLECTION,
            index_name=settings.VECTOR_INDEX_NAME,
        )
    case "pgvector":
        if not settings.POSTGRES_URI:
            raise ValueError("PostgreSQL URI is required for pgvector store")
        from core.vector_store.pgvector_store import PGVectorStore

        vector_store = PGVectorStore(
            uri=settings.POSTGRES_URI,
        )
    case _:
        raise ValueError(f"Unsupported vector store provider: {settings.VECTOR_STORE_PROVIDER}")

# Initialize storage
match settings.STORAGE_PROVIDER:
    case "local":
        storage = LocalStorage(storage_path=settings.STORAGE_PATH)
    case "aws-s3":
        if not settings.AWS_ACCESS_KEY or not settings.AWS_SECRET_ACCESS_KEY:
            raise ValueError("AWS credentials are required for S3 storage")
        storage = S3Storage(
            aws_access_key=settings.AWS_ACCESS_KEY,
            aws_secret_key=settings.AWS_SECRET_ACCESS_KEY,
            region_name=settings.AWS_REGION,
            default_bucket=settings.S3_BUCKET,
        )
    case _:
        raise ValueError(f"Unsupported storage provider: {settings.STORAGE_PROVIDER}")

# Initialize parser
parser = DatabridgeParser(
    chunk_size=settings.CHUNK_SIZE,
    chunk_overlap=settings.CHUNK_OVERLAP,
    use_unstructured_api=settings.USE_UNSTRUCTURED_API,
    unstructured_api_key=settings.UNSTRUCTURED_API_KEY,
    assemblyai_api_key=settings.ASSEMBLYAI_API_KEY,
    anthropic_api_key=settings.ANTHROPIC_API_KEY,
    use_contextual_chunking=settings.USE_CONTEXTUAL_CHUNKING,
)

# Initialize embedding model
match settings.EMBEDDING_PROVIDER:
    case "ollama":
        embedding_model = OllamaEmbeddingModel(
            base_url=settings.EMBEDDING_OLLAMA_BASE_URL,
            model_name=settings.EMBEDDING_MODEL,
        )
    case "openai":
        if not settings.OPENAI_API_KEY:
            raise ValueError("OpenAI API key is required for OpenAI embedding model")
        embedding_model = OpenAIEmbeddingModel(
            api_key=settings.OPENAI_API_KEY,
            model_name=settings.EMBEDDING_MODEL,
        )
    case _:
        raise ValueError(f"Unsupported embedding provider: {settings.EMBEDDING_PROVIDER}")

# Initialize completion model
match settings.COMPLETION_PROVIDER:
    case "ollama":
        completion_model = OllamaCompletionModel(
            model_name=settings.COMPLETION_MODEL,
            base_url=settings.COMPLETION_OLLAMA_BASE_URL,
        )
    case "openai":
        if not settings.OPENAI_API_KEY:
            raise ValueError("OpenAI API key is required for OpenAI completion model")
        completion_model = OpenAICompletionModel(
            model_name=settings.COMPLETION_MODEL,
        )
    case _:
        raise ValueError(f"Unsupported completion provider: {settings.COMPLETION_PROVIDER}")

# Initialize reranker
reranker = None
if settings.USE_RERANKING:
    match settings.RERANKER_PROVIDER:
        case "flag":
            reranker = FlagReranker(
                model_name=settings.RERANKER_MODEL,
                device=settings.RERANKER_DEVICE,
                use_fp16=settings.RERANKER_USE_FP16,
                query_max_length=settings.RERANKER_QUERY_MAX_LENGTH,
                passage_max_length=settings.RERANKER_PASSAGE_MAX_LENGTH,
            )
        case _:
            raise ValueError(f"Unsupported reranker provider: {settings.RERANKER_PROVIDER}")

# Initialize cache factory
cache_factory = LlamaCacheFactory(Path(settings.STORAGE_PATH))

# Initialize ColPali embedding model if enabled
colpali_embedding_model = ColpaliEmbeddingModel() if settings.ENABLE_COLPALI else None
colpali_vector_store = (
    MultiVectorStore(uri=settings.POSTGRES_URI) if settings.ENABLE_COLPALI else None
)

# Initialize document service with configured components
document_service = DocumentService(
    storage=storage,
    database=database,
    vector_store=vector_store,
    embedding_model=embedding_model,
    completion_model=completion_model,
    parser=parser,
    reranker=reranker,
    cache_factory=cache_factory,
    enable_colpali=settings.ENABLE_COLPALI,
    colpali_embedding_model=colpali_embedding_model,
    colpali_vector_store=colpali_vector_store,
)


async def verify_token(authorization: str = Header(None)) -> AuthContext:
    """Verify JWT Bearer token or return dev context if dev_mode is enabled."""
    # Check if dev mode is enabled
    if settings.dev_mode:
        return AuthContext(
            entity_type=EntityType(settings.dev_entity_type),
            entity_id=settings.dev_entity_id,
            permissions=set(settings.dev_permissions),
        )

    # Normal token verification flow
    if not authorization:
        raise HTTPException(
            status_code=401,
            detail="Missing authorization header",
            headers={"WWW-Authenticate": "Bearer"},
        )
    try:
        if not authorization.startswith("Bearer "):
            raise HTTPException(status_code=401, detail="Invalid authorization header")

        token = authorization[7:]  # Remove "Bearer "
        payload = jwt.decode(token, settings.JWT_SECRET_KEY, algorithms=[settings.JWT_ALGORITHM])

        if datetime.fromtimestamp(payload["exp"], UTC) < datetime.now(UTC):
            raise HTTPException(status_code=401, detail="Token expired")

        return AuthContext(
            entity_type=EntityType(payload["type"]),
            entity_id=payload["entity_id"],
            app_id=payload.get("app_id"),
            permissions=set(payload.get("permissions", ["read"])),
        )
    except jwt.InvalidTokenError as e:
        raise HTTPException(status_code=401, detail=str(e))


@app.post("/ingest/text", response_model=Document)
async def ingest_text(
    request: IngestTextRequest,
    auth: AuthContext = Depends(verify_token),
) -> Document:
    """
    Ingest a text document.

    Args:
        request: IngestTextRequest containing:
            - content: Text content to ingest
            - filename: Optional filename to help determine content type
            - metadata: Optional metadata dictionary
            - rules: Optional list of rules. Each rule should be either:
                   - MetadataExtractionRule: {"type": "metadata_extraction", "schema": {...}}
                   - NaturalLanguageRule: {"type": "natural_language", "prompt": "..."}
        auth: Authentication context

    Returns:
        Document: Metadata of ingested document
    """
    try:
        async with telemetry.track_operation(
            operation_type="ingest_text",
            user_id=auth.entity_id,
            tokens_used=len(request.content.split()),  # Approximate token count
            metadata={
                "metadata": request.metadata,
                "rules": request.rules,
                "use_colpali": request.use_colpali,
            },
        ):
            return await document_service.ingest_text(
                content=request.content,
                filename=request.filename,
                metadata=request.metadata,
                rules=request.rules,
                use_colpali=request.use_colpali,
                auth=auth,
            )
    except PermissionError as e:
        raise HTTPException(status_code=403, detail=str(e))


@app.post("/ingest/file", response_model=Document)
async def ingest_file(
    file: UploadFile,
    metadata: str = Form("{}"),
    rules: str = Form("[]"),
    auth: AuthContext = Depends(verify_token),
    use_colpali: Optional[bool] = None,
) -> Document:
    """
    Ingest a file document.

    Args:
        file: File to ingest
        metadata: JSON string of metadata
        rules: JSON string of rules list. Each rule should be either:
               - MetadataExtractionRule: {"type": "metadata_extraction", "schema": {...}}
               - NaturalLanguageRule: {"type": "natural_language", "prompt": "..."}
        auth: Authentication context

    Returns:
        Document: Metadata of ingested document
    """
    try:
        metadata_dict = json.loads(metadata)
        rules_list = json.loads(rules)
        use_colpali = bool(use_colpali)

        async with telemetry.track_operation(
            operation_type="ingest_file",
            user_id=auth.entity_id,
            metadata={
                "filename": file.filename,
                "content_type": file.content_type,
                "metadata": metadata_dict,
                "rules": rules_list,
                "use_colpali": use_colpali,
            },
        ):
            logger.info(f"API: Ingesting file with use_colpali: {use_colpali}")
            return await document_service.ingest_file(
                file=file,
                metadata=metadata_dict,
                auth=auth,
                rules=rules_list,
                use_colpali=use_colpali,
            )
    except json.JSONDecodeError as e:
        raise HTTPException(status_code=400, detail=f"Invalid JSON: {str(e)}")
    except PermissionError as e:
        raise HTTPException(status_code=403, detail=str(e))


@app.post("/retrieve/chunks", response_model=List[ChunkResult])
async def retrieve_chunks(request: RetrieveRequest, auth: AuthContext = Depends(verify_token)):
    """Retrieve relevant chunks."""
    try:
        async with telemetry.track_operation(
            operation_type="retrieve_chunks",
            user_id=auth.entity_id,
            metadata={
                "k": request.k,
                "min_score": request.min_score,
                "use_reranking": request.use_reranking,
                "use_colpali": request.use_colpali,
            },
        ):
            return await document_service.retrieve_chunks(
                request.query,
                auth,
                request.filters,
                request.k,
                request.min_score,
                request.use_reranking,
                request.use_colpali,
            )
    except PermissionError as e:
        raise HTTPException(status_code=403, detail=str(e))


@app.post("/retrieve/docs", response_model=List[DocumentResult])
async def retrieve_documents(request: RetrieveRequest, auth: AuthContext = Depends(verify_token)):
    """Retrieve relevant documents."""
    try:
        async with telemetry.track_operation(
            operation_type="retrieve_docs",
            user_id=auth.entity_id,
            metadata={
                "k": request.k,
                "min_score": request.min_score,
                "use_reranking": request.use_reranking,
                "use_colpali": request.use_colpali,
            },
        ):
            return await document_service.retrieve_docs(
                request.query,
                auth,
                request.filters,
                request.k,
                request.min_score,
                request.use_reranking,
                request.use_colpali,
            )
    except PermissionError as e:
        raise HTTPException(status_code=403, detail=str(e))


@app.post("/query", response_model=CompletionResponse)
async def query_completion(
    request: CompletionQueryRequest, auth: AuthContext = Depends(verify_token)
):
    """Generate completion using relevant chunks as context."""
    try:
        async with telemetry.track_operation(
            operation_type="query",
            user_id=auth.entity_id,
            metadata={
                "k": request.k,
                "min_score": request.min_score,
                "max_tokens": request.max_tokens,
                "temperature": request.temperature,
                "use_reranking": request.use_reranking,
                "use_colpali": request.use_colpali,
            },
        ):
            return await document_service.query(
                request.query,
                auth,
                request.filters,
                request.k,
                request.min_score,
                request.max_tokens,
                request.temperature,
                request.use_reranking,
                request.use_colpali,
            )
    except PermissionError as e:
        raise HTTPException(status_code=403, detail=str(e))


@app.get("/documents", response_model=List[Document])
async def list_documents(
    auth: AuthContext = Depends(verify_token),
    skip: int = 0,
    limit: int = 10000,
    filters: Optional[Dict[str, Any]] = None,
):
    """List accessible documents."""
    return await document_service.db.get_documents(auth, skip, limit, filters)


@app.get("/documents/{document_id}", response_model=Document)
async def get_document(document_id: str, auth: AuthContext = Depends(verify_token)):
    """Get document by ID."""
    try:
        doc = await document_service.db.get_document(document_id, auth)
        logger.info(f"Found document: {doc}")
        if not doc:
            raise HTTPException(status_code=404, detail="Document not found")
        return doc
    except HTTPException as e:
        logger.error(f"Error getting document: {e}")
        raise e


# Usage tracking endpoints
@app.get("/usage/stats")
async def get_usage_stats(auth: AuthContext = Depends(verify_token)) -> Dict[str, int]:
    """Get usage statistics for the authenticated user."""
    async with telemetry.track_operation(operation_type="get_usage_stats", user_id=auth.entity_id):
        if not auth.permissions or "admin" not in auth.permissions:
            return telemetry.get_user_usage(auth.entity_id)
        return telemetry.get_user_usage(auth.entity_id)


@app.get("/usage/recent")
async def get_recent_usage(
    auth: AuthContext = Depends(verify_token),
    operation_type: Optional[str] = None,
    since: Optional[datetime] = None,
    status: Optional[str] = None,
) -> List[Dict]:
    """Get recent usage records."""
    async with telemetry.track_operation(
        operation_type="get_recent_usage",
        user_id=auth.entity_id,
        metadata={
            "operation_type": operation_type,
            "since": since.isoformat() if since else None,
            "status": status,
        },
    ):
        if not auth.permissions or "admin" not in auth.permissions:
            records = telemetry.get_recent_usage(
                user_id=auth.entity_id, operation_type=operation_type, since=since, status=status
            )
        else:
            records = telemetry.get_recent_usage(
                operation_type=operation_type, since=since, status=status
            )

        return [
            {
                "timestamp": record.timestamp,
                "operation_type": record.operation_type,
                "tokens_used": record.tokens_used,
                "user_id": record.user_id,
                "duration_ms": record.duration_ms,
                "status": record.status,
                "metadata": record.metadata,
            }
            for record in records
        ]


# Cache endpoints
@app.post("/cache/create")
async def create_cache(
    name: str,
    model: str,
    gguf_file: str,
    filters: Optional[Dict[str, Any]] = None,
    docs: Optional[List[str]] = None,
    auth: AuthContext = Depends(verify_token),
) -> Dict[str, Any]:
    """Create a new cache with specified configuration."""
    try:
        async with telemetry.track_operation(
            operation_type="create_cache",
            user_id=auth.entity_id,
            metadata={
                "name": name,
                "model": model,
                "gguf_file": gguf_file,
                "filters": filters,
                "docs": docs,
            },
        ):
            filter_docs = set(await document_service.db.get_documents(auth, filters=filters))
            additional_docs = (
                {
                    await document_service.db.get_document(document_id=doc_id, auth=auth)
                    for doc_id in docs
                }
                if docs
                else set()
            )
            docs_to_add = list(filter_docs.union(additional_docs))
            if not docs_to_add:
                raise HTTPException(status_code=400, detail="No documents to add to cache")
            response = await document_service.create_cache(
                name, model, gguf_file, docs_to_add, filters
            )
            return response
    except PermissionError as e:
        raise HTTPException(status_code=403, detail=str(e))


@app.get("/cache/{name}")
async def get_cache(name: str, auth: AuthContext = Depends(verify_token)) -> Dict[str, Any]:
    """Get cache configuration by name."""
    try:
        async with telemetry.track_operation(
            operation_type="get_cache",
            user_id=auth.entity_id,
            metadata={"name": name},
        ):
            exists = await document_service.load_cache(name)
            return {"exists": exists}
    except PermissionError as e:
        raise HTTPException(status_code=403, detail=str(e))


@app.post("/cache/{name}/update")
async def update_cache(name: str, auth: AuthContext = Depends(verify_token)) -> Dict[str, bool]:
    """Update cache with new documents matching its filter."""
    try:
        async with telemetry.track_operation(
            operation_type="update_cache",
            user_id=auth.entity_id,
            metadata={"name": name},
        ):
            if name not in document_service.active_caches:
                exists = await document_service.load_cache(name)
                if not exists:
                    raise HTTPException(status_code=404, detail=f"Cache '{name}' not found")
            cache = document_service.active_caches[name]
            docs = await document_service.db.get_documents(auth, filters=cache.filters)
            docs_to_add = [doc for doc in docs if doc.id not in cache.docs]
            return cache.add_docs(docs_to_add)
    except PermissionError as e:
        raise HTTPException(status_code=403, detail=str(e))


@app.post("/cache/{name}/add_docs")
async def add_docs_to_cache(
    name: str, docs: List[str], auth: AuthContext = Depends(verify_token)
) -> Dict[str, bool]:
    """Add specific documents to the cache."""
    try:
        async with telemetry.track_operation(
            operation_type="add_docs_to_cache",
            user_id=auth.entity_id,
            metadata={"name": name, "docs": docs},
        ):
            cache = document_service.active_caches[name]
            docs_to_add = [
                await document_service.db.get_document(doc_id, auth)
                for doc_id in docs
                if doc_id not in cache.docs
            ]
            return cache.add_docs(docs_to_add)
    except PermissionError as e:
        raise HTTPException(status_code=403, detail=str(e))


@app.post("/cache/{name}/query")
async def query_cache(
    name: str,
    query: str,
    max_tokens: Optional[int] = None,
    temperature: Optional[float] = None,
    auth: AuthContext = Depends(verify_token),
) -> CompletionResponse:
    """Query the cache with a prompt."""
    try:
        async with telemetry.track_operation(
            operation_type="query_cache",
            user_id=auth.entity_id,
            metadata={
                "name": name,
                "query": query,
                "max_tokens": max_tokens,
                "temperature": temperature,
            },
        ):
            cache = document_service.active_caches[name]
            print(f"Cache state: {cache.state.n_tokens}", file=sys.stderr)
            return cache.query(query)  # , max_tokens, temperature)
    except PermissionError as e:
        raise HTTPException(status_code=403, detail=str(e))


@app.post("/local/generate_uri", include_in_schema=True)
async def generate_local_uri(
    name: str = Form("admin"),
    expiry_days: int = Form(30),
) -> Dict[str, str]:
    """Generate a local URI for development. This endpoint is unprotected."""
    try:
        # Clean name
        name = name.replace(" ", "_").lower()

        # Create payload
        payload = {
            "type": "developer",
            "entity_id": name,
            "permissions": ["read", "write", "admin"],
            "exp": datetime.now(UTC) + timedelta(days=expiry_days),
        }

        # Generate token
        token = jwt.encode(payload, settings.JWT_SECRET_KEY, algorithm=settings.JWT_ALGORITHM)

        # Read config for host/port
        with open("databridge.toml", "rb") as f:
            config = tomli.load(f)
        base_url = f"{config['api']['host']}:{config['api']['port']}".replace(
            "localhost", "127.0.0.1"
        )

        # Generate URI
        uri = f"databridge://{name}:{token}@{base_url}"
        return {"uri": uri}
    except Exception as e:
        logger.error(f"Error generating local URI: {e}")
        raise HTTPException(status_code=500, detail=str(e))