# routes/upload_routes.py
import os
import time
import json
import asyncio
import shutil
import uuid
from pathlib import Path
from fastapi import APIRouter, Request, File, UploadFile, HTTPException
from typing import List
import logging
from core.middleware import require_admin
from core.database import SessionLocal, GalleryImage
from src.auth_helpers import effective_user
from src.constants import GENERATED_IMAGES_DIR
from src.upload_handler import count_recent_uploads

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/api/upload", tags=["upload"])
UPLOAD_RESPONSE_HEADERS = {"X-Content-Type-Options": "nosniff"}

def setup_upload_routes(upload_handler):
    """Setup upload routes with the provided handler"""

    def _upload_root() -> str:
        from src.constants import UPLOAD_DIR
        return os.path.realpath(getattr(upload_handler, "upload_dir", UPLOAD_DIR))

    def _path_inside_upload_dir(path: str) -> bool:
        try:
            return os.path.commonpath([_upload_root(), os.path.realpath(path)]) == _upload_root()
        except Exception:
            return False

    def _resolve_upload_path(file_id: str) -> str:
        from src.constants import UPLOAD_DIR
        upload_root = getattr(upload_handler, "upload_dir", UPLOAD_DIR)
        direct = os.path.join(upload_root, file_id)
        if os.path.lexists(direct):
            if not _path_inside_upload_dir(direct):
                raise HTTPException(403, "Access denied")
            if os.path.isfile(direct):
                return direct
            raise HTTPException(404, "File not found")

        for root, _dirs, files in os.walk(upload_root, followlinks=False):
            if file_id not in files:
                continue
            path = os.path.join(root, file_id)
            if not _path_inside_upload_dir(path):
                raise HTTPException(403, "Access denied")
            if os.path.isfile(path):
                return path
            raise HTTPException(404, "File not found")

        raise HTTPException(404, "File not found")

    def _promote_chat_image_to_gallery(meta: dict, owner: str | None) -> str | None:
        """Make chat-uploaded images visible in Gallery without changing chat storage."""
        is_image_file = getattr(upload_handler, "is_image_file", None)
        if not callable(is_image_file):
            return None
        if not is_image_file(meta.get("name", ""), meta.get("mime", "")):
            return None

        source_path = meta.get("path")
        if not source_path or not os.path.isfile(source_path):
            return None

        db = SessionLocal()
        try:
            file_hash = meta.get("hash")
            if file_hash:
                q = db.query(GalleryImage).filter(
                    GalleryImage.file_hash == file_hash,
                    GalleryImage.is_active == True,  # noqa: E712
                )
                if owner:
                    q = q.filter(GalleryImage.owner == owner)
                existing = q.first()
                if existing:
                    return existing.id

            image_dir = Path(GENERATED_IMAGES_DIR)
            image_dir.mkdir(parents=True, exist_ok=True)
            ext = Path(meta.get("name") or source_path).suffix.lower()
            if ext not in {".png", ".jpg", ".jpeg", ".webp", ".gif"}:
                mime_ext = {
                    "image/png": ".png",
                    "image/jpeg": ".jpg",
                    "image/jpg": ".jpg",
                    "image/webp": ".webp",
                    "image/gif": ".gif",
                }.get(meta.get("mime", ""))
                ext = mime_ext or ".png"
            filename = f"{uuid.uuid4().hex[:12]}{ext}"
            dest_path = image_dir / filename
            shutil.copy2(source_path, dest_path)

            image_id = str(uuid.uuid4())
            db.add(GalleryImage(
                id=image_id,
                filename=filename,
                prompt=meta.get("name") or "Chat upload",
                model="chat-upload",
                owner=owner,
                file_hash=file_hash,
                width=meta.get("width"),
                height=meta.get("height"),
                file_size=meta.get("size"),
            ))
            db.commit()
            return image_id
        except Exception as e:
            db.rollback()
            logger.warning("Failed to add chat image upload to gallery: %s", e)
            return None
        finally:
            db.close()
    
    @router.post("")
    async def api_upload(request: Request, files: List[UploadFile] = File(...)):
        """Upload files with enhanced security and organization."""
        if not files:
            raise HTTPException(400, "No files uploaded")
            
        client_ip = request.client.host if request.client else "unknown"
        out = []

        # Limit concurrent uploads per IP. Count genuine recent upload events —
        # NOT the number of files in this batch. The previous check summed over
        # `files`, so a single multi-file request counted itself as N concurrent
        # uploads and tripped the limit (issue #1346: "attach more than one file
        # → the model doesn't even see them"). save_upload still enforces the
        # per-minute sliding-window rate limit per file.
        recent_uploads = count_recent_uploads(
            upload_handler.upload_rate_log.get(client_ip, []), time.time()
        )

        if recent_uploads >= upload_handler.max_concurrent_uploads:
            raise HTTPException(
                status_code=429,
                detail=f"Maximum concurrent uploads ({upload_handler.max_concurrent_uploads}) exceeded"
            )
        
        for u in files:
            try:
                owner = effective_user(request)
                meta = upload_handler.save_upload(u, client_ip, owner=owner)
                gallery_id = _promote_chat_image_to_gallery(meta, owner)
                item = {
                    "id": meta["id"],
                    "name": meta["name"],
                    "mime": meta["mime"],
                    "size": meta["size"],
                    "hash": meta["hash"],
                    "uploaded_at": meta["uploaded_at"],
                    "width": meta.get("width"),
                    "height": meta.get("height"),
                    "is_duplicate": meta.get("is_duplicate", False)
                }
                if gallery_id:
                    item["gallery_id"] = gallery_id
                out.append(item)
            except HTTPException:
                raise
            except Exception as e:
                logger.error(f"Failed to process upload {u.filename}: {str(e)}")
                continue
        
        if not out:
            raise HTTPException(500, "All file uploads failed")
            
        return {"files": out}
    
    @router.post("/cleanup")
    async def manual_cleanup(request: Request):
        """Manually trigger cleanup of old uploads."""
        require_admin(request)
        cleaned_count = upload_handler.cleanup_old_uploads()
        return {"status": "success", "files_cleaned": cleaned_count}

    @router.get("/stats")
    async def upload_stats(request: Request):
        """Get statistics about uploaded files."""
        require_admin(request)
        try:
            return upload_handler.get_upload_stats()
        except Exception as e:
            logger.error(f"Failed to get upload stats: {e}")
            raise HTTPException(500, "Failed to get upload statistics")

    @router.get("/{file_id}")
    async def download_file(request: Request, file_id: str, thumb: int = 0):
        """Serve an uploaded file by its ID. `?thumb=1` returns a small cached
        JPEG thumbnail for images (used by chat attachment previews) so the
        client isn't downloading the full-resolution photo just to show it tiny."""
        if not upload_handler.validate_upload_id(file_id):
            raise HTTPException(400, "Invalid file ID")
        import mimetypes as _mt
        # Look up original filename and owner from uploads.json
        original_name = file_id
        info = None
        uploads_db = os.path.join(_upload_root(), "uploads.json")
        if os.path.exists(uploads_db):
            with open(uploads_db, encoding="utf-8") as f:
                db = json.load(f)
            info = next((fi for fi in db.values() if fi.get("id") == file_id), None)
            if info:
                original_name = info.get("name", file_id)
        auth_mgr = getattr(request.app.state, "auth_manager", None)
        auth_configured = bool(auth_mgr and auth_mgr.is_configured)
        current_user = effective_user(request)
        file_owner = info.get("owner") if info else None
        if auth_configured:
            if not current_user:
                raise HTTPException(403, "Access denied")
            if file_owner != current_user and not auth_mgr.is_admin(current_user):
                raise HTTPException(404, "File not found")
        path = _resolve_upload_path(file_id)
        mime = (info or {}).get("mime") or _mt.guess_type(path)[0] or "application/octet-stream"
        from fastapi.responses import FileResponse
        # Downscaled thumbnail for image previews — generated once and cached.
        if thumb and mime.startswith("image/"):
            try:
                from PIL import Image, ImageOps
                thumb_dir = os.path.join(_upload_root(), ".thumbs")
                os.makedirs(thumb_dir, exist_ok=True)
                thumb_path = os.path.join(thumb_dir, file_id + ".jpg")
                if (not os.path.exists(thumb_path)
                        or os.path.getmtime(thumb_path) < os.path.getmtime(path)):
                    im = Image.open(path)
                    # iPhone / camera JPEGs encode rotation in EXIF rather than
                    # the pixel data. Browsers honour that on the original via
                    # image-orientation:from-image, but PIL strips EXIF when it
                    # saves the JPEG thumb, leaving the pixels sideways. Bake
                    # the rotation into the pixels before thumbnailing.
                    im = ImageOps.exif_transpose(im)
                    im.thumbnail((320, 320))
                    if im.mode not in ("RGB", "L"):
                        im = im.convert("RGB")
                    im.save(thumb_path, "JPEG", quality=80)
                return FileResponse(thumb_path, media_type="image/jpeg", headers=UPLOAD_RESPONSE_HEADERS)
            except Exception as e:
                logger.warning(f"Thumbnail generation failed for {file_id}: {e}")
                # Fall through to the full image.
        return FileResponse(
            path,
            media_type=mime,
            filename=original_name,
            headers=UPLOAD_RESPONSE_HEADERS,
        )

    def _load_upload_info(file_id: str):
        """Look up the uploads.json record for a file_id, with owner/auth checks."""
        info = None
        uploads_db = os.path.join(_upload_root(), "uploads.json")
        if os.path.exists(uploads_db):
            with open(uploads_db, encoding="utf-8") as f:
                db = json.load(f)
            info = next((fi for fi in db.values() if fi.get("id") == file_id), None)
        return info

    def _vision_cache_path(file_id: str) -> str:
        cache_dir = os.path.join(_upload_root(), ".vision")
        os.makedirs(cache_dir, exist_ok=True)
        return os.path.join(cache_dir, file_id + ".txt")

    @router.get("/{file_id}/vision")
    async def get_vision_text(request: Request, file_id: str, force: int = 0):
        """Return the vision-model OCR/description for an uploaded image.
        Cached under UPLOAD_DIR/.vision/{file_id}.txt — first call computes,
        subsequent loads are instant. Pass force=1 to recompute."""
        if not upload_handler.validate_upload_id(file_id):
            raise HTTPException(400, "Invalid file ID")
        info = _load_upload_info(file_id)
        auth_mgr = getattr(request.app.state, "auth_manager", None)
        auth_configured = bool(auth_mgr and auth_mgr.is_configured)
        current_user = effective_user(request)
        file_owner = info.get("owner") if info else None
        if auth_configured:
            if not current_user:
                raise HTTPException(403, "Access denied")
            if file_owner != current_user and not auth_mgr.is_admin(current_user):
                raise HTTPException(404, "File not found")
        path = _resolve_upload_path(file_id)
        import mimetypes as _mt
        mime = (info or {}).get("mime") or _mt.guess_type(path)[0] or ""
        if not mime.startswith("image/"):
            raise HTTPException(400, "Not an image")
        cache_path = _vision_cache_path(file_id)
        if not force and os.path.exists(cache_path):
            try:
                with open(cache_path, encoding="utf-8") as f:
                    return {"text": f.read(), "cached": True}
            except Exception as e:
                logger.warning(f"Vision cache read failed for {file_id}: {e}")
        from src.document_processor import analyze_image_with_vl
        try:
            text = analyze_image_with_vl(path, owner=current_user) or ""
        except Exception as e:
            logger.error(f"Vision analysis failed for {file_id}: {e}")
            raise HTTPException(500, f"Vision analysis failed: {e}")
        try:
            with open(cache_path, "w", encoding="utf-8") as f:
                f.write(text)
        except Exception as e:
            logger.warning(f"Vision cache write failed for {file_id}: {e}")
        return {"text": text, "cached": False}

    @router.put("/{file_id}/vision")
    async def put_vision_text(request: Request, file_id: str):
        """Persist a user-edited vision/OCR text for an attachment. Stored in
        the same cache file so the chat send picks it up as the override."""
        if not upload_handler.validate_upload_id(file_id):
            raise HTTPException(400, "Invalid file ID")
        info = _load_upload_info(file_id)
        if not info:
            raise HTTPException(404, "File not found")
        auth_mgr = getattr(request.app.state, "auth_manager", None)
        auth_configured = bool(auth_mgr and auth_mgr.is_configured)
        current_user = effective_user(request)
        file_owner = info.get("owner")
        if auth_configured:
            if not current_user:
                raise HTTPException(403, "Access denied")
            if file_owner != current_user and not auth_mgr.is_admin(current_user):
                raise HTTPException(404, "File not found")
        _resolve_upload_path(file_id)
        body = await request.json()
        text = (body or {}).get("text", "")
        if not isinstance(text, str):
            raise HTTPException(400, "text must be a string")
        with open(_vision_cache_path(file_id), "w", encoding="utf-8") as f:
            f.write(text)
        return {"ok": True}

    async def periodic_rate_limit_cleanup():
        """Background task to run cleanup every hour"""
        while True:
            await asyncio.sleep(3600)
            upload_handler.cleanup_rate_limits()
    
    return router, periodic_rate_limit_cleanup