from fastapi import FastAPI, UploadFile, File, Request
from fastapi.responses import HTMLResponse, JSONResponse, PlainTextResponse
from fastapi.templating import Jinja2Templates
from fastapi.staticfiles import StaticFiles
from markitdown import MarkItDown
from markitdown._stream_info import StreamInfo
import io, os, mimetypes

app = FastAPI(title="MarkItDown Converter")
templates = Jinja2Templates(directory="templates")

# markitdown supports: PDF, DOCX, PPTX, XLSX, HTML, CSV, JSON, XML,
# images (with OCR via LLM), audio, ZIP, EPUB, YouTube URLs, Wikipedia, etc.
ALLOWED_EXTENSIONS = {
    ".pdf", ".docx", ".doc", ".pptx", ".ppt", ".xlsx", ".xls",
    ".html", ".htm", ".csv", ".json", ".xml", ".epub",
    ".txt", ".md", ".rst", ".zip", ".msg",
    ".png", ".jpg", ".jpeg", ".gif", ".webp", ".bmp",
    ".mp3", ".wav", ".m4a",
}

MAX_SIZE_MB = 50


@app.get("/", response_class=HTMLResponse)
async def index(request: Request):
    return templates.TemplateResponse("index.html", {"request": request})


@app.post("/convert")
async def convert(file: UploadFile = File(...)):
    # Validate extension
    _, ext = os.path.splitext(file.filename or "")
    ext = ext.lower()
    if ext not in ALLOWED_EXTENSIONS:
        return JSONResponse(
            {"error": f"Unsupported file type: '{ext}'. Supported: {', '.join(sorted(ALLOWED_EXTENSIONS))}"},
            status_code=400
        )

    # Read into memory
    data = await file.read()
    size_mb = len(data) / (1024 * 1024)
    if size_mb > MAX_SIZE_MB:
        return JSONResponse(
            {"error": f"File too large ({size_mb:.1f} MB). Max: {MAX_SIZE_MB} MB"},
            status_code=413
        )

    try:
        md = MarkItDown()
        stream = io.BytesIO(data)
        mime = mimetypes.types_map.get(ext, "application/octet-stream")
        result = md.convert_stream(
            stream,
            stream_info=StreamInfo(
                mimetype=mime,
                extension=ext,
                filename=file.filename,
            )
        )
        markdown_text = result.text_content or ""
        return JSONResponse({
            "markdown": markdown_text,
            "filename": file.filename,
            "size_kb": round(len(data) / 1024, 1),
            "chars": len(markdown_text),
        })
    except Exception as e:
        return JSONResponse({"error": f"Conversion failed: {str(e)}"}, status_code=500)