from fastapi import APIRouter, Depends, HTTPException, UploadFile, File, Form, Request, Query, Header, Response
from fastapi.responses import StreamingResponse
from sqlalchemy.orm import Session
from sqlalchemy import or_, func
from typing import List, Optional
import math
import re
import io
import hashlib

from .database import get_db
from .storage import get_storage, S3Storage, MULTIPART_CHUNK_SIZE
from .models import Project, Package, Artifact, Tag, Upload, Consumer
from .schemas import (
    ProjectCreate, ProjectResponse,
    PackageCreate, PackageResponse,
    ArtifactResponse,
    TagCreate, TagResponse,
    UploadResponse,
    ConsumerResponse,
    HealthResponse,
    PaginatedResponse, PaginationMeta,
    ResumableUploadInitRequest,
    ResumableUploadInitResponse,
    ResumableUploadPartResponse,
    ResumableUploadCompleteRequest,
    ResumableUploadCompleteResponse,
    ResumableUploadStatusResponse,
)
from .metadata import extract_metadata

router = APIRouter()


def get_user_id(request: Request) -> str:
    """Extract user ID from request (simplified for now)"""
    api_key = request.headers.get("X-Orchard-API-Key")
    if api_key:
        return "api-user"
    auth = request.headers.get("Authorization")
    if auth:
        return "bearer-user"
    return "anonymous"


# Health check
@router.get("/health", response_model=HealthResponse)
def health_check():
    return HealthResponse(status="ok")


# Project routes
@router.get("/api/v1/projects", response_model=PaginatedResponse[ProjectResponse])
def list_projects(
    request: Request,
    page: int = Query(default=1, ge=1, description="Page number"),
    limit: int = Query(default=20, ge=1, le=100, description="Items per page"),
    search: Optional[str] = Query(default=None, description="Search by project name"),
    db: Session = Depends(get_db),
):
    user_id = get_user_id(request)

    # Base query - filter by access
    query = db.query(Project).filter(
        or_(Project.is_public == True, Project.created_by == user_id)
    )

    # Apply search filter (case-insensitive)
    if search:
        query = query.filter(func.lower(Project.name).contains(search.lower()))

    # Get total count before pagination
    total = query.count()

    # Apply pagination
    offset = (page - 1) * limit
    projects = query.order_by(Project.name).offset(offset).limit(limit).all()

    # Calculate total pages
    total_pages = math.ceil(total / limit) if total > 0 else 1

    return PaginatedResponse(
        items=projects,
        pagination=PaginationMeta(
            page=page,
            limit=limit,
            total=total,
            total_pages=total_pages,
        ),
    )


@router.post("/api/v1/projects", response_model=ProjectResponse)
def create_project(project: ProjectCreate, request: Request, db: Session = Depends(get_db)):
    user_id = get_user_id(request)

    existing = db.query(Project).filter(Project.name == project.name).first()
    if existing:
        raise HTTPException(status_code=400, detail="Project already exists")

    db_project = Project(
        name=project.name,
        description=project.description,
        is_public=project.is_public,
        created_by=user_id,
    )
    db.add(db_project)
    db.commit()
    db.refresh(db_project)
    return db_project


@router.get("/api/v1/projects/{project_name}", response_model=ProjectResponse)
def get_project(project_name: str, db: Session = Depends(get_db)):
    project = db.query(Project).filter(Project.name == project_name).first()
    if not project:
        raise HTTPException(status_code=404, detail="Project not found")
    return project


# Package routes
@router.get("/api/v1/project/{project_name}/packages", response_model=List[PackageResponse])
def list_packages(project_name: str, db: Session = Depends(get_db)):
    project = db.query(Project).filter(Project.name == project_name).first()
    if not project:
        raise HTTPException(status_code=404, detail="Project not found")

    packages = db.query(Package).filter(Package.project_id == project.id).order_by(Package.name).all()
    return packages


@router.post("/api/v1/project/{project_name}/packages", response_model=PackageResponse)
def create_package(project_name: str, package: PackageCreate, db: Session = Depends(get_db)):
    project = db.query(Project).filter(Project.name == project_name).first()
    if not project:
        raise HTTPException(status_code=404, detail="Project not found")

    existing = db.query(Package).filter(Package.project_id == project.id, Package.name == package.name).first()
    if existing:
        raise HTTPException(status_code=400, detail="Package already exists in this project")

    db_package = Package(
        project_id=project.id,
        name=package.name,
        description=package.description,
    )
    db.add(db_package)
    db.commit()
    db.refresh(db_package)
    return db_package


# Upload artifact
@router.post("/api/v1/project/{project_name}/{package_name}/upload", response_model=UploadResponse)
def upload_artifact(
    project_name: str,
    package_name: str,
    request: Request,
    file: UploadFile = File(...),
    tag: Optional[str] = Form(None),
    db: Session = Depends(get_db),
    storage: S3Storage = Depends(get_storage),
    content_length: Optional[int] = Header(None, alias="Content-Length"),
):
    user_id = get_user_id(request)

    # Get project and package
    project = db.query(Project).filter(Project.name == project_name).first()
    if not project:
        raise HTTPException(status_code=404, detail="Project not found")

    package = db.query(Package).filter(Package.project_id == project.id, Package.name == package_name).first()
    if not package:
        raise HTTPException(status_code=404, detail="Package not found")

    # Extract format-specific metadata before storing
    file_metadata = {}
    if file.filename:
        # Read file into memory for metadata extraction
        file_content = file.file.read()
        file.file.seek(0)

        # Extract metadata
        file_metadata = extract_metadata(
            io.BytesIO(file_content),
            file.filename,
            file.content_type
        )

    # Store file (uses multipart for large files)
    sha256_hash, size, s3_key = storage.store(file.file, content_length)

    # Check if this is a deduplicated upload
    deduplicated = False

    # Create or update artifact record
    artifact = db.query(Artifact).filter(Artifact.id == sha256_hash).first()
    if artifact:
        artifact.ref_count += 1
        deduplicated = True
        # Merge metadata if new metadata was extracted
        if file_metadata and artifact.format_metadata:
            artifact.format_metadata = {**artifact.format_metadata, **file_metadata}
        elif file_metadata:
            artifact.format_metadata = file_metadata
    else:
        artifact = Artifact(
            id=sha256_hash,
            size=size,
            content_type=file.content_type,
            original_name=file.filename,
            created_by=user_id,
            s3_key=s3_key,
            format_metadata=file_metadata or {},
        )
        db.add(artifact)

    # Record upload
    upload = Upload(
        artifact_id=sha256_hash,
        package_id=package.id,
        original_name=file.filename,
        uploaded_by=user_id,
        source_ip=request.client.host if request.client else None,
    )
    db.add(upload)

    # Create tag if provided
    if tag:
        existing_tag = db.query(Tag).filter(Tag.package_id == package.id, Tag.name == tag).first()
        if existing_tag:
            existing_tag.artifact_id = sha256_hash
            existing_tag.created_by = user_id
        else:
            new_tag = Tag(
                package_id=package.id,
                name=tag,
                artifact_id=sha256_hash,
                created_by=user_id,
            )
            db.add(new_tag)

    db.commit()

    return UploadResponse(
        artifact_id=sha256_hash,
        size=size,
        project=project_name,
        package=package_name,
        tag=tag,
        format_metadata=artifact.format_metadata,
        deduplicated=deduplicated,
    )


# Resumable upload endpoints
@router.post("/api/v1/project/{project_name}/{package_name}/upload/init", response_model=ResumableUploadInitResponse)
def init_resumable_upload(
    project_name: str,
    package_name: str,
    init_request: ResumableUploadInitRequest,
    request: Request,
    db: Session = Depends(get_db),
    storage: S3Storage = Depends(get_storage),
):
    """
    Initialize a resumable upload session.
    Client must provide the SHA256 hash of the file in advance.
    """
    user_id = get_user_id(request)

    # Validate project and package
    project = db.query(Project).filter(Project.name == project_name).first()
    if not project:
        raise HTTPException(status_code=404, detail="Project not found")

    package = db.query(Package).filter(Package.project_id == project.id, Package.name == package_name).first()
    if not package:
        raise HTTPException(status_code=404, detail="Package not found")

    # Check if artifact already exists (deduplication)
    existing_artifact = db.query(Artifact).filter(Artifact.id == init_request.expected_hash).first()
    if existing_artifact:
        # File already exists - increment ref count and return immediately
        existing_artifact.ref_count += 1

        # Record the upload
        upload = Upload(
            artifact_id=init_request.expected_hash,
            package_id=package.id,
            original_name=init_request.filename,
            uploaded_by=user_id,
            source_ip=request.client.host if request.client else None,
        )
        db.add(upload)

        # Create tag if provided
        if init_request.tag:
            existing_tag = db.query(Tag).filter(
                Tag.package_id == package.id, Tag.name == init_request.tag
            ).first()
            if existing_tag:
                existing_tag.artifact_id = init_request.expected_hash
                existing_tag.created_by = user_id
            else:
                new_tag = Tag(
                    package_id=package.id,
                    name=init_request.tag,
                    artifact_id=init_request.expected_hash,
                    created_by=user_id,
                )
                db.add(new_tag)

        db.commit()

        return ResumableUploadInitResponse(
            upload_id=None,
            already_exists=True,
            artifact_id=init_request.expected_hash,
            chunk_size=MULTIPART_CHUNK_SIZE,
        )

    # Initialize resumable upload
    session = storage.initiate_resumable_upload(init_request.expected_hash)

    return ResumableUploadInitResponse(
        upload_id=session["upload_id"],
        already_exists=False,
        artifact_id=None,
        chunk_size=MULTIPART_CHUNK_SIZE,
    )


@router.put("/api/v1/project/{project_name}/{package_name}/upload/{upload_id}/part/{part_number}")
def upload_part(
    project_name: str,
    package_name: str,
    upload_id: str,
    part_number: int,
    request: Request,
    db: Session = Depends(get_db),
    storage: S3Storage = Depends(get_storage),
):
    """
    Upload a part of a resumable upload.
    Part numbers start at 1.
    """
    # Validate project and package exist
    project = db.query(Project).filter(Project.name == project_name).first()
    if not project:
        raise HTTPException(status_code=404, detail="Project not found")

    package = db.query(Package).filter(Package.project_id == project.id, Package.name == package_name).first()
    if not package:
        raise HTTPException(status_code=404, detail="Package not found")

    if part_number < 1:
        raise HTTPException(status_code=400, detail="Part number must be >= 1")

    # Read part data from request body
    import asyncio
    loop = asyncio.new_event_loop()

    async def read_body():
        return await request.body()

    try:
        data = loop.run_until_complete(read_body())
    finally:
        loop.close()

    if not data:
        raise HTTPException(status_code=400, detail="No data in request body")

    try:
        part_info = storage.upload_part(upload_id, part_number, data)
        return ResumableUploadPartResponse(
            part_number=part_info["PartNumber"],
            etag=part_info["ETag"],
        )
    except ValueError as e:
        raise HTTPException(status_code=404, detail=str(e))


@router.post("/api/v1/project/{project_name}/{package_name}/upload/{upload_id}/complete")
def complete_resumable_upload(
    project_name: str,
    package_name: str,
    upload_id: str,
    complete_request: ResumableUploadCompleteRequest,
    request: Request,
    db: Session = Depends(get_db),
    storage: S3Storage = Depends(get_storage),
):
    """Complete a resumable upload"""
    user_id = get_user_id(request)

    # Validate project and package
    project = db.query(Project).filter(Project.name == project_name).first()
    if not project:
        raise HTTPException(status_code=404, detail="Project not found")

    package = db.query(Package).filter(Package.project_id == project.id, Package.name == package_name).first()
    if not package:
        raise HTTPException(status_code=404, detail="Package not found")

    try:
        sha256_hash, s3_key = storage.complete_resumable_upload(upload_id)
    except ValueError as e:
        raise HTTPException(status_code=404, detail=str(e))

    # Get file size from S3
    obj_info = storage.get_object_info(s3_key)
    size = obj_info["size"] if obj_info else 0

    # Create artifact record
    artifact = Artifact(
        id=sha256_hash,
        size=size,
        s3_key=s3_key,
        created_by=user_id,
        format_metadata={},
    )
    db.add(artifact)

    # Record upload
    upload = Upload(
        artifact_id=sha256_hash,
        package_id=package.id,
        uploaded_by=user_id,
        source_ip=request.client.host if request.client else None,
    )
    db.add(upload)

    # Create tag if provided
    if complete_request.tag:
        existing_tag = db.query(Tag).filter(
            Tag.package_id == package.id, Tag.name == complete_request.tag
        ).first()
        if existing_tag:
            existing_tag.artifact_id = sha256_hash
            existing_tag.created_by = user_id
        else:
            new_tag = Tag(
                package_id=package.id,
                name=complete_request.tag,
                artifact_id=sha256_hash,
                created_by=user_id,
            )
            db.add(new_tag)

    db.commit()

    return ResumableUploadCompleteResponse(
        artifact_id=sha256_hash,
        size=size,
        project=project_name,
        package=package_name,
        tag=complete_request.tag,
    )


@router.delete("/api/v1/project/{project_name}/{package_name}/upload/{upload_id}")
def abort_resumable_upload(
    project_name: str,
    package_name: str,
    upload_id: str,
    storage: S3Storage = Depends(get_storage),
):
    """Abort a resumable upload"""
    try:
        storage.abort_resumable_upload(upload_id)
        return {"status": "aborted"}
    except ValueError as e:
        raise HTTPException(status_code=404, detail=str(e))


@router.get("/api/v1/project/{project_name}/{package_name}/upload/{upload_id}/status")
def get_upload_status(
    project_name: str,
    package_name: str,
    upload_id: str,
    storage: S3Storage = Depends(get_storage),
):
    """Get status of a resumable upload"""
    try:
        parts = storage.list_upload_parts(upload_id)
        uploaded_parts = [p["PartNumber"] for p in parts]
        total_bytes = sum(p.get("Size", 0) for p in parts)

        return ResumableUploadStatusResponse(
            upload_id=upload_id,
            uploaded_parts=uploaded_parts,
            total_uploaded_bytes=total_bytes,
        )
    except ValueError as e:
        raise HTTPException(status_code=404, detail=str(e))


# Download artifact with range request support
@router.get("/api/v1/project/{project_name}/{package_name}/+/{ref}")
def download_artifact(
    project_name: str,
    package_name: str,
    ref: str,
    request: Request,
    db: Session = Depends(get_db),
    storage: S3Storage = Depends(get_storage),
    range: Optional[str] = Header(None),
):
    # Get project and package
    project = db.query(Project).filter(Project.name == project_name).first()
    if not project:
        raise HTTPException(status_code=404, detail="Project not found")

    package = db.query(Package).filter(Package.project_id == project.id, Package.name == package_name).first()
    if not package:
        raise HTTPException(status_code=404, detail="Package not found")

    # Resolve reference to artifact
    artifact = None

    # Check for explicit prefixes
    if ref.startswith("artifact:"):
        artifact_id = ref[9:]
        artifact = db.query(Artifact).filter(Artifact.id == artifact_id).first()
    elif ref.startswith("tag:") or ref.startswith("version:"):
        tag_name = ref.split(":", 1)[1]
        tag = db.query(Tag).filter(Tag.package_id == package.id, Tag.name == tag_name).first()
        if tag:
            artifact = db.query(Artifact).filter(Artifact.id == tag.artifact_id).first()
    else:
        # Try as tag name first
        tag = db.query(Tag).filter(Tag.package_id == package.id, Tag.name == ref).first()
        if tag:
            artifact = db.query(Artifact).filter(Artifact.id == tag.artifact_id).first()
        else:
            # Try as direct artifact ID
            artifact = db.query(Artifact).filter(Artifact.id == ref).first()

    if not artifact:
        raise HTTPException(status_code=404, detail="Artifact not found")

    filename = artifact.original_name or f"{artifact.id}"

    # Handle range requests
    if range:
        stream, content_length, content_range = storage.get_stream(artifact.s3_key, range)

        headers = {
            "Content-Disposition": f'attachment; filename="{filename}"',
            "Accept-Ranges": "bytes",
            "Content-Length": str(content_length),
        }
        if content_range:
            headers["Content-Range"] = content_range

        return StreamingResponse(
            stream,
            status_code=206,  # Partial Content
            media_type=artifact.content_type or "application/octet-stream",
            headers=headers,
        )

    # Full download
    stream, content_length, _ = storage.get_stream(artifact.s3_key)

    return StreamingResponse(
        stream,
        media_type=artifact.content_type or "application/octet-stream",
        headers={
            "Content-Disposition": f'attachment; filename="{filename}"',
            "Accept-Ranges": "bytes",
            "Content-Length": str(content_length),
        },
    )


# HEAD request for download (to check file info without downloading)
@router.head("/api/v1/project/{project_name}/{package_name}/+/{ref}")
def head_artifact(
    project_name: str,
    package_name: str,
    ref: str,
    db: Session = Depends(get_db),
    storage: S3Storage = Depends(get_storage),
):
    # Get project and package
    project = db.query(Project).filter(Project.name == project_name).first()
    if not project:
        raise HTTPException(status_code=404, detail="Project not found")

    package = db.query(Package).filter(Package.project_id == project.id, Package.name == package_name).first()
    if not package:
        raise HTTPException(status_code=404, detail="Package not found")

    # Resolve reference to artifact (same logic as download)
    artifact = None
    if ref.startswith("artifact:"):
        artifact_id = ref[9:]
        artifact = db.query(Artifact).filter(Artifact.id == artifact_id).first()
    elif ref.startswith("tag:") or ref.startswith("version:"):
        tag_name = ref.split(":", 1)[1]
        tag = db.query(Tag).filter(Tag.package_id == package.id, Tag.name == tag_name).first()
        if tag:
            artifact = db.query(Artifact).filter(Artifact.id == tag.artifact_id).first()
    else:
        tag = db.query(Tag).filter(Tag.package_id == package.id, Tag.name == ref).first()
        if tag:
            artifact = db.query(Artifact).filter(Artifact.id == tag.artifact_id).first()
        else:
            artifact = db.query(Artifact).filter(Artifact.id == ref).first()

    if not artifact:
        raise HTTPException(status_code=404, detail="Artifact not found")

    filename = artifact.original_name or f"{artifact.id}"

    return Response(
        content=b"",
        media_type=artifact.content_type or "application/octet-stream",
        headers={
            "Content-Disposition": f'attachment; filename="{filename}"',
            "Accept-Ranges": "bytes",
            "Content-Length": str(artifact.size),
            "X-Artifact-Id": artifact.id,
        },
    )


# Compatibility route
@router.get("/project/{project_name}/{package_name}/+/{ref}")
def download_artifact_compat(
    project_name: str,
    package_name: str,
    ref: str,
    request: Request,
    db: Session = Depends(get_db),
    storage: S3Storage = Depends(get_storage),
    range: Optional[str] = Header(None),
):
    return download_artifact(project_name, package_name, ref, request, db, storage, range)


# Tag routes
@router.get("/api/v1/project/{project_name}/{package_name}/tags", response_model=List[TagResponse])
def list_tags(project_name: str, package_name: str, db: Session = Depends(get_db)):
    project = db.query(Project).filter(Project.name == project_name).first()
    if not project:
        raise HTTPException(status_code=404, detail="Project not found")

    package = db.query(Package).filter(Package.project_id == project.id, Package.name == package_name).first()
    if not package:
        raise HTTPException(status_code=404, detail="Package not found")

    tags = db.query(Tag).filter(Tag.package_id == package.id).order_by(Tag.name).all()
    return tags


@router.post("/api/v1/project/{project_name}/{package_name}/tags", response_model=TagResponse)
def create_tag(
    project_name: str,
    package_name: str,
    tag: TagCreate,
    request: Request,
    db: Session = Depends(get_db),
):
    user_id = get_user_id(request)

    project = db.query(Project).filter(Project.name == project_name).first()
    if not project:
        raise HTTPException(status_code=404, detail="Project not found")

    package = db.query(Package).filter(Package.project_id == project.id, Package.name == package_name).first()
    if not package:
        raise HTTPException(status_code=404, detail="Package not found")

    # Verify artifact exists
    artifact = db.query(Artifact).filter(Artifact.id == tag.artifact_id).first()
    if not artifact:
        raise HTTPException(status_code=404, detail="Artifact not found")

    # Create or update tag
    existing = db.query(Tag).filter(Tag.package_id == package.id, Tag.name == tag.name).first()
    if existing:
        existing.artifact_id = tag.artifact_id
        existing.created_by = user_id
        db.commit()
        db.refresh(existing)
        return existing

    db_tag = Tag(
        package_id=package.id,
        name=tag.name,
        artifact_id=tag.artifact_id,
        created_by=user_id,
    )
    db.add(db_tag)
    db.commit()
    db.refresh(db_tag)
    return db_tag


# Consumer routes
@router.get("/api/v1/project/{project_name}/{package_name}/consumers", response_model=List[ConsumerResponse])
def get_consumers(project_name: str, package_name: str, db: Session = Depends(get_db)):
    project = db.query(Project).filter(Project.name == project_name).first()
    if not project:
        raise HTTPException(status_code=404, detail="Project not found")

    package = db.query(Package).filter(Package.project_id == project.id, Package.name == package_name).first()
    if not package:
        raise HTTPException(status_code=404, detail="Package not found")

    consumers = db.query(Consumer).filter(Consumer.package_id == package.id).order_by(Consumer.last_access.desc()).all()
    return consumers


# Artifact by ID
@router.get("/api/v1/artifact/{artifact_id}", response_model=ArtifactResponse)
def get_artifact(artifact_id: str, db: Session = Depends(get_db)):
    artifact = db.query(Artifact).filter(Artifact.id == artifact_id).first()
    if not artifact:
        raise HTTPException(status_code=404, detail="Artifact not found")
    return artifact