"""
OpenWolf PDF Parser — Lightweight HF Space
Only does PDF text extraction + chunk splitting.
No LLM, no bge-m3, no heavy ML.
"""

import os, sys, json, urllib.parse, re
from pathlib import Path
from fastapi import FastAPI, Request, HTTPException
from fastapi.responses import JSONResponse

app = FastAPI(title="OpenWolf PDF Parser")

@app.get("/health")
async def health():
    return {"status": "ok"}

@app.post("/parse")
async def parse_pdf(request: Request):
    """
    解析 PDF，返回全文文本
    Body: { file_path: "inputs/xxx.pdf", repo: "owner/repo", pat: "ghp_xxx" }
    """
    body = await request.json()
    file_path = body.get("file_path", "")
    repo = body.get("repo", os.environ.get("GITHUB_REPO", ""))
    pat = body.get("pat", os.environ.get("GITHUB_PAT", ""))

    if not file_path:
        raise HTTPException(400, "file_path required")

    local_path = Path("/app") / file_path
    if not local_path.exists():
        # Download from GitHub
        import requests as req
        encoded = '/'.join(urllib.parse.quote(s, safe='') for s in file_path.split('/'))
        url = f"https://api.github.com/repos/{repo}/contents/{encoded}"
        headers = {"Authorization": f"token {pat}", "Accept": "application/vnd.github.raw"} if pat else {"Accept": "application/vnd.github.raw"}
        resp = req.get(url, headers=headers, timeout=120)
        if resp.status_code != 200:
            return JSONResponse({"ok": False, "error": f"download failed HTTP {resp.status_code}"})
        local_path.parent.mkdir(parents=True, exist_ok=True)
        local_path.write_bytes(resp.content)

    # Extract text
    import pdfplumber
    text = ""
    with pdfplumber.open(local_path) as pdf:
        for page in pdf.pages:
            t = page.extract_text()
            if t:
                text += t + "\n"

    return {"ok": True, "text": text, "chars": len(text)}

@app.post("/chunks")
async def get_chunks(request: Request):
    """
    从文本或 PDF 生成稳定 chunk 列表
    Body: { file_path: "...", chunk_size: 4500 }
    或:   { text: "...", chunk_size: 4500 }
    """
    body = await request.json()
    chunk_size = int(body.get("chunk_size", 4500))

    text = body.get("text", "")
    if not text:
        file_path = body.get("file_path", "")
        if file_path:
            # Read local file
            local_path = Path("/app") / file_path
            if local_path.exists():
                ext = file_path.rsplit(".", 1)[-1].lower()
                if ext == "pdf":
                    import pdfplumber
                    with pdfplumber.open(local_path) as pdf:
                        text = "\n".join(page.extract_text() or "" for page in pdf.pages)
                else:
                    text = local_path.read_text(encoding="utf-8", errors="ignore")

    if not text:
        return JSONResponse({"ok": False, "error": "no text provided"})

    chunks = []
    i = 0
    n = len(text)
    while i < n:
        end = min(i + chunk_size, n)
        cut = text.rfind("\n\n", i, end)
        if cut == -1 or cut <= i:
            cut = end
        chunk = text[i:cut].strip()
        if chunk:
            chunks.append(chunk)
        i = cut if cut > i else end

    return {"ok": True, "chunks": chunks, "total": len(chunks), "total_chars": n}