import json
import logging
import os
import shutil
import uuid
from pathlib import Path
from typing import Optional, List

from fastapi import APIRouter, UploadFile, File, Form, HTTPException

from haystack.pipeline import Pipeline
from rest_api.config import PIPELINE_YAML_PATH, FILE_UPLOAD_PATH, INDEXING_PIPELINE_NAME

logger = logging.getLogger(__name__)
router = APIRouter()

try:
    INDEXING_PIPELINE = Pipeline.load_from_yaml(Path(PIPELINE_YAML_PATH), pipeline_name=INDEXING_PIPELINE_NAME)
except KeyError:
    INDEXING_PIPELINE = None
    logger.info("Indexing Pipeline not found in the YAML configuration. File Upload API will not be available.")


os.makedirs(FILE_UPLOAD_PATH, exist_ok=True)  # create directory for uploading files


@router.post("/file-upload")
def file_upload(
    files: List[UploadFile] = File(...),
    meta: Optional[str] = Form("null"),  # JSON serialized string
    remove_numeric_tables: Optional[bool] = Form(None),
    remove_whitespace: Optional[bool] = Form(None),
    remove_empty_lines: Optional[bool] = Form(None),
    remove_header_footer: Optional[bool] = Form(None),
    valid_languages: Optional[List[str]] = Form(None),
    split_by: Optional[str] = Form(None),
    split_length: Optional[int] = Form(None),
    split_overlap: Optional[int] = Form(None),
    split_respect_sentence_boundary: Optional[bool] = Form(None),
):
    if not INDEXING_PIPELINE:
        raise HTTPException(status_code=501, detail="Indexing Pipeline is not configured.")

    file_paths: list = []
    file_metas: list = []
    meta = json.loads(meta) or {}

    for file in files:
        try:
            file_path = Path(FILE_UPLOAD_PATH) / f"{uuid.uuid4().hex}_{file.filename}"
            with file_path.open("wb") as buffer:
                shutil.copyfileobj(file.file, buffer)

            file_paths.append(file_path)
            meta["name"] = file.filename
            file_metas.append(meta)
        finally:
            file.file.close()

    INDEXING_PIPELINE.run(
            file_paths=file_paths,
            remove_numeric_tables=remove_numeric_tables,
            remove_whitespace=remove_whitespace,
            remove_empty_lines=remove_empty_lines,
            remove_header_footer=remove_header_footer,
            valid_languages=valid_languages,
            split_by=split_by,
            split_length=split_length,
            split_overlap=split_overlap,
            split_respect_sentence_boundary=split_respect_sentence_boundary,
            meta=file_metas,
    )