import os
import time
import requests
import logging
import json
from typing import List, Optional
from langchain_core.documents import Document
from fastapi import HTTPException, status

log = logging.getLogger(__name__)


class DatalabMarkerLoader:
    def __init__(
        self,
        file_path: str,
        api_key: str,
        api_base_url: str,
        additional_config: Optional[str] = None,
        use_llm: bool = False,
        skip_cache: bool = False,
        force_ocr: bool = False,
        paginate: bool = False,
        strip_existing_ocr: bool = False,
        disable_image_extraction: bool = False,
        format_lines: bool = False,
        output_format: str = None,
    ):
        self.file_path = file_path
        self.api_key = api_key
        self.api_base_url = api_base_url
        self.additional_config = additional_config
        self.use_llm = use_llm
        self.skip_cache = skip_cache
        self.force_ocr = force_ocr
        self.paginate = paginate
        self.strip_existing_ocr = strip_existing_ocr
        self.disable_image_extraction = disable_image_extraction
        self.format_lines = format_lines
        self.output_format = output_format

    def _get_mime_type(self, filename: str) -> str:
        ext = filename.rsplit(".", 1)[-1].lower()
        mime_map = {
            "pdf": "application/pdf",
            "xls": "application/vnd.ms-excel",
            "xlsx": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
            "ods": "application/vnd.oasis.opendocument.spreadsheet",
            "doc": "application/msword",
            "docx": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
            "odt": "application/vnd.oasis.opendocument.text",
            "ppt": "application/vnd.ms-powerpoint",
            "pptx": "application/vnd.openxmlformats-officedocument.presentationml.presentation",
            "odp": "application/vnd.oasis.opendocument.presentation",
            "html": "text/html",
            "epub": "application/epub+zip",
            "png": "image/png",
            "jpeg": "image/jpeg",
            "jpg": "image/jpeg",
            "webp": "image/webp",
            "gif": "image/gif",
            "tiff": "image/tiff",
        }
        return mime_map.get(ext, "application/octet-stream")

    def check_marker_request_status(self, request_id: str) -> dict:
        url = f"{self.api_base_url}/{request_id}"
        headers = {"X-Api-Key": self.api_key}
        try:
            response = requests.get(url, headers=headers)
            response.raise_for_status()
            result = response.json()
            log.info(f"Marker API status check for request {request_id}: {result}")
            return result
        except requests.HTTPError as e:
            log.error(f"Error checking Marker request status: {e}")
            raise HTTPException(
                status.HTTP_502_BAD_GATEWAY,
                detail=f"Failed to check Marker request: {e}",
            )
        except ValueError as e:
            log.error(f"Invalid JSON checking Marker request: {e}")
            raise HTTPException(
                status.HTTP_502_BAD_GATEWAY, detail=f"Invalid JSON: {e}"
            )

    def load(self) -> List[Document]:
        filename = os.path.basename(self.file_path)
        mime_type = self._get_mime_type(filename)
        headers = {"X-Api-Key": self.api_key}

        form_data = {
            "use_llm": str(self.use_llm).lower(),
            "skip_cache": str(self.skip_cache).lower(),
            "force_ocr": str(self.force_ocr).lower(),
            "paginate": str(self.paginate).lower(),
            "strip_existing_ocr": str(self.strip_existing_ocr).lower(),
            "disable_image_extraction": str(self.disable_image_extraction).lower(),
            "format_lines": str(self.format_lines).lower(),
            "output_format": self.output_format,
        }

        if self.additional_config and self.additional_config.strip():
            form_data["additional_config"] = self.additional_config

        log.info(
            f"Datalab Marker POST request parameters: {{'filename': '{filename}', 'mime_type': '{mime_type}', **{form_data}}}"
        )

        try:
            with open(self.file_path, "rb") as f:
                files = {"file": (filename, f, mime_type)}
                response = requests.post(
                    f"{self.api_base_url}",
                    data=form_data,
                    files=files,
                    headers=headers,
                )
                response.raise_for_status()
                result = response.json()
        except FileNotFoundError:
            raise HTTPException(
                status.HTTP_404_NOT_FOUND, detail=f"File not found: {self.file_path}"
            )
        except requests.HTTPError as e:
            raise HTTPException(
                status.HTTP_400_BAD_REQUEST,
                detail=f"Datalab Marker request failed: {e}",
            )
        except ValueError as e:
            raise HTTPException(
                status.HTTP_502_BAD_GATEWAY, detail=f"Invalid JSON response: {e}"
            )
        except Exception as e:
            raise HTTPException(status.HTTP_500_INTERNAL_SERVER_ERROR, detail=str(e))

        if not result.get("success"):
            raise HTTPException(
                status.HTTP_400_BAD_REQUEST,
                detail=f"Datalab Marker request failed: {result.get('error', 'Unknown error')}",
            )

        check_url = result.get("request_check_url")
        request_id = result.get("request_id")

        # Check if this is a direct response (self-hosted) or polling response (DataLab)
        if check_url:
            # DataLab polling pattern
            for _ in range(300):  # Up to 10 minutes
                time.sleep(2)
                try:
                    poll_response = requests.get(check_url, headers=headers)
                    poll_response.raise_for_status()
                    poll_result = poll_response.json()
                except (requests.HTTPError, ValueError) as e:
                    raw_body = poll_response.text
                    log.error(f"Polling error: {e}, response body: {raw_body}")
                    raise HTTPException(
                        status.HTTP_502_BAD_GATEWAY, detail=f"Polling failed: {e}"
                    )

                status_val = poll_result.get("status")
                success_val = poll_result.get("success")

                if status_val == "complete":
                    summary = {
                        k: poll_result.get(k)
                        for k in (
                            "status",
                            "output_format",
                            "success",
                            "error",
                            "page_count",
                            "total_cost",
                        )
                    }
                    log.info(
                        f"Marker processing completed successfully: {json.dumps(summary, indent=2)}"
                    )
                    break

                if status_val == "failed" or success_val is False:
                    log.error(
                        f"Marker poll failed full response: {json.dumps(poll_result, indent=2)}"
                    )
                    error_msg = (
                        poll_result.get("error")
                        or "Marker returned failure without error message"
                    )
                    raise HTTPException(
                        status.HTTP_400_BAD_REQUEST,
                        detail=f"Marker processing failed: {error_msg}",
                    )
            else:
                raise HTTPException(
                    status.HTTP_504_GATEWAY_TIMEOUT,
                    detail="Marker processing timed out",
                )

            if not poll_result.get("success", False):
                error_msg = poll_result.get("error") or "Unknown processing error"
                raise HTTPException(
                    status.HTTP_400_BAD_REQUEST,
                    detail=f"Final processing failed: {error_msg}",
                )

            # DataLab format - content in format-specific fields
            content_key = self.output_format.lower()
            raw_content = poll_result.get(content_key)
            final_result = poll_result
        else:
            # Self-hosted direct response - content in "output" field
            if "output" in result:
                log.info("Self-hosted Marker returned direct response without polling")
                raw_content = result.get("output")
                final_result = result
            else:
                available_fields = (
                    list(result.keys())
                    if isinstance(result, dict)
                    else "non-dict response"
                )
                raise HTTPException(
                    status.HTTP_502_BAD_GATEWAY,
                    detail=f"Custom Marker endpoint returned success but no 'output' field found. Available fields: {available_fields}. Expected either 'request_check_url' for polling or 'output' field for direct response.",
                )

        if self.output_format.lower() == "json":
            full_text = json.dumps(raw_content, indent=2)
        elif self.output_format.lower() in {"markdown", "html"}:
            full_text = str(raw_content).strip()
        else:
            raise HTTPException(
                status.HTTP_400_BAD_REQUEST,
                detail=f"Unsupported output format: {self.output_format}",
            )

        if not full_text:
            raise HTTPException(
                status.HTTP_400_BAD_REQUEST,
                detail="Marker returned empty content",
            )

        marker_output_dir = os.path.join("/app/backend/data/uploads", "marker_output")
        os.makedirs(marker_output_dir, exist_ok=True)

        file_ext_map = {"markdown": "md", "json": "json", "html": "html"}
        file_ext = file_ext_map.get(self.output_format.lower(), "txt")
        output_filename = f"{os.path.splitext(filename)[0]}.{file_ext}"
        output_path = os.path.join(marker_output_dir, output_filename)

        try:
            with open(output_path, "w", encoding="utf-8") as f:
                f.write(full_text)
            log.info(f"Saved Marker output to: {output_path}")
        except Exception as e:
            log.warning(f"Failed to write marker output to disk: {e}")

        metadata = {
            "source": filename,
            "output_format": final_result.get("output_format", self.output_format),
            "page_count": final_result.get("page_count", 0),
            "processed_with_llm": self.use_llm,
            "request_id": request_id or "",
        }

        images = final_result.get("images", {})
        if images:
            metadata["image_count"] = len(images)
            metadata["images"] = json.dumps(list(images.keys()))

        for k, v in metadata.items():
            if isinstance(v, (dict, list)):
                metadata[k] = json.dumps(v)
            elif v is None:
                metadata[k] = ""

        return [Document(page_content=full_text, metadata=metadata)]
