from __future__ import annotations

import logging
import os
import re
from dataclasses import dataclass
from enum import Enum
from io import BytesIO
from os import PathLike
from pathlib import Path
from typing import Any, Callable, Iterable, Optional

import pdfplumber
import requests
from PIL import Image

from common.constants import MAXIMUM_PAGE_NUMBER

try:
    from deepdoc.parser.pdf_parser import RAGFlowPdfParser
except Exception:

    class RAGFlowPdfParser:
        pass


from deepdoc.parser.utils import extract_pdf_outlines


class OpenDataLoaderContentType(str, Enum):
    IMAGE = "image"
    TABLE = "table"
    TEXT = "text"
    EQUATION = "equation"


@dataclass
class _BBox:
    page_no: int
    x0: float
    y0: float
    x1: float
    y1: float


_TEXT_TYPES = {"heading", "title", "paragraph", "text", "list", "list_item", "caption"}
_TABLE_TYPES = {"table"}
_IMAGE_TYPES = {"image", "picture", "figure"}
_FORMULA_TYPES = {"formula", "equation"}


def _as_float(v) -> Optional[float]:
    try:
        return float(v)
    except Exception:
        return None


def _bbox_from_element(el: dict) -> Optional[_BBox]:
    bb = el.get("bounding box") or el.get("bounding_box") or el.get("bbox")
    pn = el.get("page number")
    if pn is None:
        pn = el.get("page_number")
    if pn is None:
        pn = el.get("page")
    if bb is None or pn is None:
        return None
    if not isinstance(bb, (list, tuple)) or len(bb) < 4:
        return None
    coords = [_as_float(x) for x in bb[:4]]
    if any(c is None for c in coords):
        return None
    try:
        page_no = int(pn)
    except Exception:
        return None
    # OpenDataLoader emits [left, bottom, right, top] in PDF points.
    left, bottom, right, top = coords
    x0, x1 = min(left, right), max(left, right)
    y0, y1 = min(bottom, top), max(bottom, top)
    return _BBox(page_no=page_no, x0=x0, y0=y0, x1=x1, y1=y1)


def _iter_elements(node: Any) -> Iterable[dict]:
    if isinstance(node, dict):
        if "type" in node and ("content" in node or "text" in node or "cells" in node):
            yield node
        for v in node.values():
            yield from _iter_elements(v)
    elif isinstance(node, list):
        for item in node:
            yield from _iter_elements(item)


def _element_text(el: dict) -> str:
    content = el.get("content")
    if isinstance(content, str):
        return content
    text = el.get("text")
    if isinstance(text, str):
        return text
    # tables may expose cells; join row-wise if needed
    cells = el.get("cells")
    if isinstance(cells, list):
        rows: dict[int, list[str]] = {}
        for c in cells:
            if not isinstance(c, dict):
                continue
            row = c.get("row") or c.get("row_index") or 0
            rows.setdefault(int(row), []).append(str(c.get("content") or c.get("text") or ""))
        return "\n".join(" | ".join(v) for _, v in sorted(rows.items()))
    return ""


def _element_html(el: dict) -> str:
    for key in ("html", "html_content"):
        v = el.get(key)
        if isinstance(v, str) and v.strip():
            return v
    return ""


class OpenDataLoaderParser(RAGFlowPdfParser):
    def __init__(self):
        self.logger = logging.getLogger(self.__class__.__name__)
        self.page_images: list[Image.Image] = []
        self.page_from = 0
        self.page_to = 10_000
        self.outlines = []
        self.api_url = os.environ.get("OPENDATALOADER_APISERVER", "").rstrip("/")
        self.api_key = os.environ.get("OPENDATALOADER_API_KEY", "").strip()
        try:
            self.timeout = int(os.environ.get("OPENDATALOADER_TIMEOUT", "600") or "600")
        except ValueError:
            self.logger.warning("[OpenDataLoader] Invalid OPENDATALOADER_TIMEOUT, falling back to 600s")
            self.timeout = 600

    def check_installation(self) -> bool:
        """Return True when the OpenDataLoader service is reachable."""
        if not self.api_url:
            self.logger.warning("[OpenDataLoader] OPENDATALOADER_APISERVER is not set. Start the opendataloader service and set the env var.")
            return False
        try:
            headers = {"Authorization": f"Bearer {self.api_key}"} if self.api_key else {}
            resp = requests.get(f"{self.api_url}/health", timeout=5, headers=headers)
            if resp.status_code == 200:
                return True
            self.logger.warning(f"[OpenDataLoader] Health check returned {resp.status_code}: {resp.text[:200]}")
            return False
        except Exception as exc:
            self.logger.warning(f"[OpenDataLoader] Health check failed: {exc}")
            return False

    def __images__(self, fnm, zoomin: int = 1, page_from=0, page_to=MAXIMUM_PAGE_NUMBER, callback=None):
        self.page_from = page_from
        self.page_to = page_to
        bytes_io = None
        try:
            if not isinstance(fnm, (str, PathLike)):
                bytes_io = fnm if isinstance(fnm, BytesIO) else BytesIO(fnm)
            opener = pdfplumber.open(fnm) if isinstance(fnm, (str, PathLike)) else pdfplumber.open(bytes_io)
            with opener as pdf:
                pages = pdf.pages[page_from:page_to]
                self.page_images = [p.to_image(resolution=72 * zoomin, antialias=True).original for p in pages]
        except Exception as e:
            self.page_images = []
            self.logger.exception(e)
        finally:
            if bytes_io:
                bytes_io.close()

    def _make_line_tag(self, bbox: _BBox) -> str:
        if bbox is None:
            return ""
        # Guard: only emit a crop tag when the page was actually rendered.
        if not self.page_images or bbox.page_no <= 0 or len(self.page_images) < bbox.page_no:
            return ""
        x0, x1 = bbox.x0, bbox.x1
        # OpenDataLoader bbox uses PDF coordinate space (origin bottom-left).
        # Convert to image-space (origin top-left) by subtracting from page height.
        _, page_height = self.page_images[bbox.page_no - 1].size
        top = page_height - bbox.y1
        bott = page_height - bbox.y0
        return "@@{}\t{:.1f}\t{:.1f}\t{:.1f}\t{:.1f}##".format(bbox.page_no, x0, x1, top, bott)

    @staticmethod
    def extract_positions(txt: str) -> list[tuple[list[int], float, float, float, float]]:
        poss = []
        for tag in re.findall(r"@@[0-9-]+\t[0-9.\t]+##", txt):
            pn, left, right, top, bottom = tag.strip("#").strip("@").split("\t")
            left, right, top, bottom = float(left), float(right), float(top), float(bottom)
            poss.append(([int(p) - 1 for p in pn.split("-")], left, right, top, bottom))
        return poss

    def crop(self, text: str, ZM: int = 1, need_position: bool = False):
        if not self.page_images:
            return (None, None) if need_position else None
        imgs = []
        poss = self.extract_positions(text)
        if not poss:
            return (None, None) if need_position else None
        # Drop positions whose page indices fall outside the rendered range.
        max_page = len(self.page_images) - 1
        poss = [p for p in poss if all(0 <= pn <= max_page for pn in p[0])]
        if not poss:
            return (None, None) if need_position else None
        GAP = 6
        pos = poss[0]
        poss.insert(0, ([pos[0][0]], pos[1], pos[2], max(0, pos[3] - 120), max(pos[3] - GAP, 0)))
        pos = poss[-1]
        poss.append(([pos[0][-1]], pos[1], pos[2], min(self.page_images[pos[0][-1]].size[1], pos[4] + GAP), min(self.page_images[pos[0][-1]].size[1], pos[4] + 120)))
        positions = []
        for ii, (pns, left, right, top, bottom) in enumerate(poss):
            if bottom <= top:
                bottom = top + 4
            img0 = self.page_images[pns[0]]
            x0, y0, x1, y1 = int(left), int(top), int(right), int(min(bottom, img0.size[1]))
            crop0 = img0.crop((x0, y0, x1, y1))
            imgs.append(crop0)
            if 0 < ii < len(poss) - 1:
                positions.append((pns[0] + self.page_from, x0, x1, y0, y1))
            remain_bottom = bottom - img0.size[1]
            for pn in pns[1:]:
                if remain_bottom <= 0:
                    break
                page = self.page_images[pn]
                x0, y0, x1, y1 = int(left), 0, int(right), int(min(remain_bottom, page.size[1]))
                cimgp = page.crop((x0, y0, x1, y1))
                imgs.append(cimgp)
                if 0 < ii < len(poss) - 1:
                    positions.append((pn + self.page_from, x0, x1, y0, y1))
                remain_bottom -= page.size[1]
        if not imgs:
            return (None, None) if need_position else None
        height = sum(i.size[1] + GAP for i in imgs)
        width = max(i.size[0] for i in imgs)
        pic = Image.new("RGB", (width, int(height)), (245, 245, 245))
        h = 0
        for ii, img in enumerate(imgs):
            if ii == 0 or ii + 1 == len(imgs):
                img = img.convert("RGBA")
                overlay = Image.new("RGBA", img.size, (0, 0, 0, 0))
                overlay.putalpha(128)
                img = Image.alpha_composite(img, overlay).convert("RGB")
            pic.paste(img, (0, int(h)))
            h += img.size[1] + GAP
        return (pic, positions) if need_position else pic

    def _cropout_region(self, bbox: _BBox, zoomin: int = 1):
        if not self.page_images:
            return None, ""
        idx = (bbox.page_no - 1) - self.page_from
        if idx < 0 or idx >= len(self.page_images):
            return None, ""
        page_img = self.page_images[idx]
        W, H = page_img.size
        x0 = max(0.0, min(float(bbox.x0), W - 1))
        y0 = max(0.0, min(float(H - bbox.y1), H - 1))
        x1 = max(x0 + 1.0, min(float(bbox.x1), W))
        y1 = max(y0 + 1.0, min(float(H - bbox.y0), H))
        try:
            crop = page_img.crop((int(x0), int(y0), int(x1), int(y1))).convert("RGB")
        except Exception:
            return None, ""
        pos = (bbox.page_no - 1 if bbox.page_no > 0 else 0, x0, x1, y0, y1)
        return crop, [pos]

    def _classify(self, el_type: str) -> str:
        t = (el_type or "").lower()
        if t in _TABLE_TYPES:
            return OpenDataLoaderContentType.TABLE.value
        if t in _IMAGE_TYPES:
            return OpenDataLoaderContentType.IMAGE.value
        if t in _FORMULA_TYPES:
            return OpenDataLoaderContentType.EQUATION.value
        # Preserve the original structural type (heading, title, paragraph,
        # list, caption, …) so downstream parsers can apply heading/title heuristics.
        return t if t else OpenDataLoaderContentType.TEXT.value

    def _transfer_from_json(self, root: Any, parse_method: str):
        sections: list[tuple[str, ...]] = []
        tables: list = []
        for el in _iter_elements(root):
            el_type = self._classify(el.get("type", ""))
            bbox = _bbox_from_element(el)
            tag = self._make_line_tag(bbox) if bbox else ""

            if el_type == OpenDataLoaderContentType.TABLE.value:
                html = _element_html(el) or _element_text(el)
                img = None
                positions = ""
                if bbox:
                    img, positions = self._cropout_region(bbox)
                tables.append(((img, html), positions if positions else ""))
                continue

            if el_type == OpenDataLoaderContentType.IMAGE.value:
                img = None
                positions = ""
                if bbox:
                    img, positions = self._cropout_region(bbox)
                caption = _element_text(el)
                tables.append(((img, [caption] if caption else [""]), positions if positions else ""))
                continue

            text = _element_text(el).strip()
            if not text:
                continue
            if parse_method in {"manual", "pipeline"}:
                sections.append((text, el_type, tag))
            elif parse_method == "paper":
                sections.append((text + tag, el_type))
            else:
                sections.append((text, tag))
        return sections, tables

    @staticmethod
    def _sections_from_markdown(md: str, parse_method: str) -> list[tuple[str, ...]]:
        txt = (md or "").strip()
        if not txt:
            return []
        if parse_method in {"manual", "pipeline"}:
            return [(txt, OpenDataLoaderContentType.TEXT.value, "")]
        if parse_method == "paper":
            return [(txt, OpenDataLoaderContentType.TEXT.value)]
        return [(txt, "")]

    def parse_pdf(
        self,
        filepath: str | PathLike[str],
        binary: BytesIO | bytes | None = None,
        callback: Optional[Callable] = None,
        *,
        parse_method: str = "raw",
        hybrid: Optional[str] = None,
        image_output: Optional[str] = None,
        sanitize: Optional[bool] = None,
    ):
        self.outlines = extract_pdf_outlines(binary if binary is not None else filepath)

        if not self.api_url:
            raise RuntimeError("[OpenDataLoader] OPENDATALOADER_APISERVER is not configured. Please start the opendataloader service and set the env var.")

        # Render page images locally — used by _make_line_tag() and crop().
        # The image rendering stays on the RAGFlow host; only the Java conversion
        # runs inside the opendataloader service container.
        try:
            if binary is not None:
                src = BytesIO(binary) if isinstance(binary, (bytes, bytearray)) else binary
                self.__images__(src, zoomin=1)
            else:
                self.__images__(str(filepath), zoomin=1)
        except Exception as e:
            self.logger.warning(f"[OpenDataLoader] render pages failed: {e}")

        # Read PDF bytes for the multipart upload
        if binary is not None:
            pdf_bytes = binary if isinstance(binary, (bytes, bytearray)) else binary.getvalue()
        else:
            with open(filepath, "rb") as fh:
                pdf_bytes = fh.read()

        filename = Path(str(filepath)).name or "input.pdf"

        if callback:
            callback(0.1, f"[OpenDataLoader] Sending '{filename}' to service")

        form_data: dict[str, str] = {}
        if hybrid:
            form_data["hybrid"] = hybrid
        if image_output:
            form_data["image_output"] = image_output
        if sanitize is not None:
            form_data["sanitize"] = "true" if sanitize else "false"

        headers = {"Authorization": f"Bearer {self.api_key}"} if self.api_key else {}
        last_exc: Exception | None = None
        for attempt in range(1, 4):
            try:
                self.logger.info(f"[OpenDataLoader] POST {self.api_url}/file_parse for '{filename}' (attempt {attempt})")
                resp = requests.post(
                    url=f"{self.api_url}/file_parse",
                    files={"file": (filename, pdf_bytes, "application/pdf")},
                    data=form_data,
                    headers=headers,
                    timeout=self.timeout,
                )
                resp.raise_for_status()
                result = resp.json()
                break
            except Exception as exc:
                last_exc = exc
                self.logger.warning(f"[OpenDataLoader] attempt {attempt} failed: {exc}")
        else:
            raise RuntimeError(f"[OpenDataLoader] service call failed after 3 attempts: {last_exc}") from last_exc

        if callback:
            callback(0.7, "[OpenDataLoader] Processing response")

        # Service response structure:
        # {
        #   "json_doc": {...} | null,   # structured parse tree (preferred)
        #   "md_text":  "..." | null    # markdown fallback when json_doc is absent
        # }
        json_doc = result.get("json_doc")
        md_text = result.get("md_text")

        sections: list[tuple[str, ...]] = []
        tables: list = []
        if json_doc is not None:
            sections, tables = self._transfer_from_json(json_doc, parse_method=parse_method)
        if not sections and md_text:
            sections = self._sections_from_markdown(md_text, parse_method=parse_method)

        if callback:
            callback(1.0, f"[OpenDataLoader] Done. Sections: {len(sections)}, Tables: {len(tables)}")

        return sections, tables


if __name__ == "__main__":
    logging.basicConfig(level=logging.INFO)
    parser = OpenDataLoaderParser()
    print("OpenDataLoader service reachable:", parser.check_installation())
