"""
GLM-OCR Hugging Face Space app for PDF/image OCR with header inclusion
and table-structure stabilization for downstream bank-statement pipelines.

Hard-coded knobs (no environment variables required).

Primary goal for reconcile rate:
- preserve right-most columns (often "Balance") by higher DPI render + right padding
- keep tables as tables (convert markdown pipe tables -> HTML table)
- return ---page-separator--- between pages
"""

# Patch asyncio first (before Gradio imports it) to suppress Python 3.13 cleanup noise
import asyncio
try:
    _orig_close = asyncio.BaseEventLoop.close
    def _safe_close(self):
        try:
            _orig_close(self)
        except (ValueError, OSError):
            pass
    asyncio.BaseEventLoop.close = _safe_close
except Exception:
    pass

import logging
import os
import re
import html
import tempfile
from typing import List, Tuple

import yaml
import gradio as gr

import glmocr

log = logging.getLogger("glmocr_app")
logging.basicConfig(level=logging.INFO)

GLMOCR_BASE = os.path.dirname(glmocr.__file__)
CONFIG_PATH = os.path.join(GLMOCR_BASE, "config.yaml")
FORMATTER_PATH = os.path.join(GLMOCR_BASE, "postprocess", "result_formatter.py")


# ============================================================
# HARD-CODED SETTINGS (edit these numbers to tune quality/speed)
# ============================================================

# 1) GLM-OCR MaaS API key
# IMPORTANT: Do NOT hard-code secrets in a public Space.
# If your Space is public, switch to HF Secrets instead.
GLMOCR_API_KEY = "e2b138b2005a41cb9d87dd18805838aa.lyd51L23rcDbsw0w"

# 2) Render quality (higher = better OCR for small/right-aligned digits; slower)
RENDER_SCALE = 2.2   # try 2.5 if Balance column is still missing

# 3) Add padding to protect columns near edges (Balance is usually right-most)
PAD_LEFT_FRAC = 0.02
PAD_RIGHT_FRAC = 0.06  # try 0.10 if right-most balances are missing
PAD_TOP_FRAC = 0.01
PAD_BOTTOM_FRAC = 0.01

# 4) Mild contrast boost (helps faint gray text)
ENABLE_CONTRAST = True

# 5) Header/footer band heuristics
DEFAULT_ZONE_FRAC = 0.12      # OCR band for header (top 12%) when regions not available
PDF_HEADER_BAND_FRAC = 0.10   # PDF text fallback: take top 10% words if clip returns empty

# Footer: disabled by default to avoid duplicating what GLM already returns
ENABLE_FOOTER_OCR = False
PDF_FOOTER_BAND_FRAC = 0.88   # bottom 12% (if footer enabled)

# MaaS minimum image sizes for crops; we pad if needed
MIN_CROP_HEIGHT = 112
MIN_CROP_PIXELS = 112 * 112

# ============================================================


# Single shared parser to avoid re-init per request
_parser = None

def get_parser():
    global _parser
    if _parser is None:
        from glmocr import GlmOcr
        _parser = GlmOcr(
            api_key=GLMOCR_API_KEY,
            mode="maas",
        )
    return _parser


# ---------------------------------------------------------------------------
# Best-effort config tweaks (safe to fail on read-only HF env)
# ---------------------------------------------------------------------------
try:
    with open(CONFIG_PATH, "r") as f:
        config = yaml.safe_load(f)
    config["pipeline"]["maas"]["enabled"] = True
    config["pipeline"]["maas"]["api_key"] = GLMOCR_API_KEY
    with open(CONFIG_PATH, "w") as f:
        yaml.dump(config, f, default_flow_style=False, sort_keys=False)
except Exception:
    pass

# Best-effort formatter tweak: avoid stripping header/footer labels
try:
    with open(FORMATTER_PATH, "r") as f:
        source = f.read()
    for label in ('"header"', "'header'", '"footer"', "'footer'", '"doc_header"', "'doc_header'", '"doc_footer"', "'doc_footer'"):
        source = re.sub(r",\s*" + re.escape(label), "", source)
        source = re.sub(re.escape(label) + r"\s*,", "", source)
        source = re.sub(re.escape(label), "", source)
    with open(FORMATTER_PATH, "w") as f:
        f.write(source)
except Exception:
    pass


# --------------------------
# Header/footer helpers
# --------------------------
def get_header_footer_zones(regions, norm_height=1000):
    """Infer header/footer extents from bbox regions if present."""
    if not regions:
        return None, None
    y_tops, y_bottoms = [], []
    for r in regions:
        bbox = r.get("bbox_2d") if isinstance(r, dict) else getattr(r, "bbox_2d", None)
        if bbox and len(bbox) >= 4:
            y_tops.append(bbox[1])
            y_bottoms.append(bbox[3])
    if not y_tops:
        return None, None
    return min(y_tops) / norm_height, max(y_bottoms) / norm_height


def extract_zone_text_pdf(pdf_path, page_num, y_start_frac, y_end_frac):
    """Extract text from a horizontal band using a clip rect (works if PDF has text layer)."""
    try:
        import pymupdf as fitz
        doc = fitz.open(pdf_path)
        page = doc[page_num]
        h, w = page.rect.height, page.rect.width
        rect = fitz.Rect(0, h * y_start_frac, w, h * y_end_frac)
        text = page.get_text(clip=rect).strip()
        doc.close()
        return text
    except Exception:
        return ""


def extract_pdf_text_in_band(pdf_path, page_num, y_start_frac, y_end_frac):
    """Extract words whose bbox intersects a vertical band (robust fallback)."""
    try:
        import pymupdf as fitz
        doc = fitz.open(pdf_path)
        page = doc[page_num]
        h = page.rect.height
        y_lo = h * y_start_frac
        y_hi = h * y_end_frac
        words = page.get_text("words")
        doc.close()
        parts = []
        for w in words:
            if len(w) >= 5:
                y0, y1 = float(w[1]), float(w[3])
                if y0 < y_hi and y1 > y_lo:
                    parts.append(w[4])
        return " ".join(parts).strip()
    except Exception:
        return ""


def ocr_zone(image_path, y_start_frac, y_end_frac):
    """Run OCR on a horizontal band. Pads small crops to meet MaaS minimum size."""
    zone_name = "header" if y_end_frac < 0.5 else "footer"
    try:
        from PIL import Image
        img = Image.open(image_path).convert("RGB")
        w, h = img.size
        y0 = max(0, int(h * y_start_frac))
        y1 = min(h, int(h * y_end_frac))
        if y1 <= y0:
            return ""

        crop = img.crop((0, y0, w, y1))
        cw, ch = crop.size

        if ch < MIN_CROP_HEIGHT or (cw * ch) < MIN_CROP_PIXELS:
            need_h = max(ch, MIN_CROP_HEIGHT)
            need_w = max(cw, 1)
            if (need_w * need_h) < MIN_CROP_PIXELS:
                need_w = max(need_w, (MIN_CROP_PIXELS + need_h - 1) // need_h)
            canvas = Image.new("RGB", (need_w, need_h), (255, 255, 255))
            if zone_name == "header":
                canvas.paste(crop, (0, 0))
            else:
                canvas.paste(crop, (0, need_h - ch))
            crop = canvas

        fd, path = tempfile.mkstemp(suffix=".jpg")
        os.close(fd)
        try:
            crop.save(path, "JPEG", quality=92)
            parser = get_parser()
            out = parser.parse(path)
            if not isinstance(out, list):
                out = [out]
            if out and getattr(out[0], "markdown_result", None):
                return (out[0].markdown_result or "").strip()
        finally:
            try:
                os.unlink(path)
            except Exception:
                pass
    except Exception as e:
        log.warning("[%s] ocr_zone failed: %s", zone_name, e, exc_info=True)
    return ""


def fix_account_number(hdr: str) -> str:
    """Fix common account-number formatting issues."""
    if not hdr:
        return hdr
    if "Account Number:" in hdr and "Account Number: " not in hdr:
        m = re.search(r"[0-9]{5,}", hdr)
        if m:
            hdr = hdr.replace("Account Number:", "Account Number: " + m.group(0))
    acct_match = re.search(r"Account Number: ([0-9]{5,})", hdr)
    if acct_match:
        acct = acct_match.group(1)
        if hdr.startswith(acct):
            hdr = hdr[len(acct):].lstrip()
    return hdr


# --------------------------
# Table stabilization helpers
# --------------------------
def close_unclosed_html(md: str) -> str:
    """Close unclosed <table>/<tr>/<td> tags to prevent bleed."""
    if not md:
        return md
    open_tags = re.findall(r"<(table|tbody|thead|tr|td|th)\b", md, flags=re.IGNORECASE)
    close_tags = re.findall(r"</(table|tbody|thead|tr|td|th)>", md, flags=re.IGNORECASE)

    def count(tags, name):
        return sum(1 for t in tags if t.lower() == name)

    for tag in reversed(["td", "th", "tr", "thead", "tbody", "table"]):
        opened = count(open_tags, tag)
        closed = count(close_tags, tag)
        if opened > closed:
            md += ("</%s>" % tag) * (opened - closed)
    return md


def looks_like_markdown_table(block: str) -> bool:
    """Detect simple markdown pipe tables."""
    lines = [ln.rstrip() for ln in block.strip().splitlines() if ln.strip()]
    if len(lines) < 2:
        return False
    if "|" not in lines[0]:
        return False
    sep = lines[1].replace(" ", "")
    return ("---" in sep) and ("|" in sep)


def md_table_to_html(block: str) -> str:
    """Convert a simple markdown pipe table to HTML table (best-effort)."""
    lines = [ln.strip() for ln in block.strip().splitlines() if ln.strip()]
    if len(lines) < 2:
        return block

    def split_row(row: str):
        row = row.strip()
        if row.startswith("|"):
            row = row[1:]
        if row.endswith("|"):
            row = row[:-1]
        return [p.strip() for p in row.split("|")]

    header = split_row(lines[0])
    body_lines = [ln for ln in lines[2:] if "|" in ln]

    html_rows = []
    html_rows.append("<tr>" + "".join(f"<th>{html.escape(c)}</th>" for c in header) + "</tr>")
    for ln in body_lines:
        cols = split_row(ln)
        if len(cols) < len(header):
            cols += [""] * (len(header) - len(cols))
        html_rows.append("<tr>" + "".join(f"<td>{html.escape(c)}</td>" for c in cols[:len(header)]) + "</tr>")
    return "<table>\n" + "\n".join(html_rows) + "\n</table>"


def normalize_money_glyphs(text: str) -> str:
    """Conservative normalization for OCR number quirks."""
    if not text:
        return text
    t = text.replace("−", "-").replace("–", "-").replace("—", "-")
    t = re.sub(r"\(\s*\$?\s*([0-9]{1,3}(?:,[0-9]{3})*|[0-9]+)(\.[0-9]{2})\s*\)", r"-\1\2", t)

    def o_to_zero(m):
        token = m.group(0)
        return token.replace("O", "0").replace("o", "0")
    t = re.sub(r"\b[0-9Oo\$,.\-]{4,}\b", o_to_zero, t)
    return t


def stabilize_tables_and_text(page_md: str) -> str:
    """Convert markdown pipe tables to HTML and close tags."""
    if not page_md:
        return page_md
    page_md = normalize_money_glyphs(page_md)

    blocks = re.split(r"\n\s*\n", page_md.strip())
    out_blocks = []
    for b in blocks:
        if looks_like_markdown_table(b):
            out_blocks.append(md_table_to_html(b))
        else:
            out_blocks.append(b)

    stabilized = "\n\n".join(out_blocks)
    return close_unclosed_html(stabilized)


# --------------------------
# PDF rendering with padding (critical for Balance column)
# --------------------------
def render_pdf_pages_to_images(pdf_path: str) -> Tuple[List[str], List[int]]:
    import pymupdf as fitz
    from PIL import Image, ImageEnhance

    doc = fitz.open(pdf_path)
    page_images: List[str] = []
    page_heights: List[int] = []

    for i in range(len(doc)):
        page = doc[i]
        pix = page.get_pixmap(matrix=fitz.Matrix(RENDER_SCALE, RENDER_SCALE), alpha=False)

        img = Image.frombytes("RGB", [pix.width, pix.height], pix.samples)

        if ENABLE_CONTRAST:
            img = ImageEnhance.Contrast(img).enhance(1.12)

        w, h = img.size
        pad_l = int(w * PAD_LEFT_FRAC)
        pad_r = int(w * PAD_RIGHT_FRAC)
        pad_t = int(h * PAD_TOP_FRAC)
        pad_b = int(h * PAD_BOTTOM_FRAC)

        if any(p > 0 for p in (pad_l, pad_r, pad_t, pad_b)):
            canvas = Image.new("RGB", (w + pad_l + pad_r, h + pad_t + pad_b), (255, 255, 255))
            canvas.paste(img, (pad_l, pad_t))
            img = canvas

        img_path = os.path.join(tempfile.gettempdir(), f"glmocr_page_{os.getpid()}_{i}.png")
        img.save(img_path, "PNG", compress_level=6)
        page_images.append(img_path)
        page_heights.append(img.height)

    doc.close()
    return page_images, page_heights


# --------------------------
# GLM-OCR result extraction
# --------------------------
def get_page_md_and_regions(page_result):
    md = ""
    if hasattr(page_result, "markdown_result") and page_result.markdown_result:
        md = (page_result.markdown_result or "").strip()
    regions = []
    if hasattr(page_result, "json_result"):
        jr = page_result.json_result
        if isinstance(jr, dict) and "regions" in jr:
            regions = jr.get("regions") or []
        elif isinstance(jr, list) and len(jr) > 0:
            r = jr[0] if isinstance(jr[0], list) else jr
            if isinstance(r, list):
                regions = r
            elif isinstance(r, dict) and "regions" in r:
                regions = r.get("regions") or []
    return md, regions


# --------------------------
# Main entry
# --------------------------
def run_ocr(uploaded_file):
    if uploaded_file is None:
        return "Please upload a file."

    page_images = []
    try:
        path = uploaded_file.name if hasattr(uploaded_file, "name") else str(uploaded_file)
        is_pdf = path.lower().endswith(".pdf")
        parser = get_parser()

        page_heights = []

        if is_pdf:
            page_images, page_heights = render_pdf_pages_to_images(path)
            results = parser.parse(page_images)
        else:
            page_images = [path]
            page_heights = [1000]
            results = parser.parse(path)

        if not isinstance(results, list):
            results = [results]

        all_pages = []
        for page_num, page_result in enumerate(results):
            page_md, regions = get_page_md_and_regions(page_result)
            img_h = page_heights[page_num] if page_num < len(page_heights) else 1000
            header_end_frac, footer_start_frac = get_header_footer_zones(regions, img_h)

            he = header_end_frac if header_end_frac is not None else DEFAULT_ZONE_FRAC
            fs = footer_start_frac if footer_start_frac is not None else (1.0 - DEFAULT_ZONE_FRAC)

            # clamp
            he = max(0.02, min(0.25, he))
            fs = max(0.75, min(0.98, fs))

            parts = []

            # Header inclusion: PDF text -> band words -> OCR band
            hdr = ""
            if is_pdf:
                hdr = extract_zone_text_pdf(path, page_num, 0, he)
                if not (hdr and hdr.strip()):
                    hdr = extract_pdf_text_in_band(path, page_num, 0, PDF_HEADER_BAND_FRAC)
            if not (hdr and hdr.strip()) and page_num < len(page_images):
                hdr = ocr_zone(page_images[page_num], 0, he)
            if hdr and hdr.strip():
                parts.append(fix_account_number(normalize_money_glyphs(hdr.strip())))

            # Main OCR markdown, stabilized
            if page_md and page_md.strip():
                parts.append(stabilize_tables_and_text(page_md.strip()))

            # Optional footer
            if ENABLE_FOOTER_OCR and page_num < len(page_images):
                ftr = ""
                if is_pdf:
                    ftr = extract_zone_text_pdf(path, page_num, fs, 1.0)
                    if not (ftr and ftr.strip()):
                        ftr = extract_pdf_text_in_band(path, page_num, PDF_FOOTER_BAND_FRAC, 1.0)
                if not (ftr and ftr.strip()):
                    ftr = ocr_zone(page_images[page_num], fs, 1.0)
                if ftr and ftr.strip():
                    parts.append(normalize_money_glyphs(ftr.strip()))

            if parts:
                all_pages.append("\n\n".join(parts))

        return "\n\n---page-separator---\n\n".join(all_pages) if all_pages else "(No content)"

    except Exception as e:
        import traceback
        log.exception("run_ocr failed: %s", e)
        return f"Error: {e}\n\n{traceback.format_exc()}"

    finally:
        # cleanup rendered images
        for p in page_images:
            try:
                if isinstance(p, str) and p.endswith(".png") and "glmocr_page_" in os.path.basename(p):
                    os.unlink(p)
            except Exception:
                pass


with gr.Blocks(title="GLM-OCR") as demo:
    gr.Markdown("# GLM-OCR\nUpload a PDF or image. Headers included; tables stabilized.")
    file_in = gr.File(label="Upload PDF or image", file_types=[".pdf", ".png", ".jpg", ".jpeg", ".tiff", ".bmp"])
    run_btn = gr.Button("Run OCR", variant="primary")
    out = gr.Textbox(lines=40, label="Output (markdown)")
    run_btn.click(fn=run_ocr, inputs=file_in, outputs=out)

if __name__ == "__main__":
    demo.launch()