#!/usr/bin/env python3
import csv
import html
import json
import re
import sys
import zipfile
from pathlib import Path
from urllib.request import Request, urlopen
from xml.etree.ElementTree import iterparse


NS = {
    "main": "http://schemas.openxmlformats.org/spreadsheetml/2006/main",
    "rel": "http://schemas.openxmlformats.org/officeDocument/2006/relationships",
    "pkgrel": "http://schemas.openxmlformats.org/package/2006/relationships",
}


def metadata_download_url(capture_path: Path) -> str:
    capture = json.loads(capture_path.read_text())
    for body in capture["documentBodies"]:
        payload = body.get("body", {})
        text = payload.get("body", "") if isinstance(payload, dict) else ""
        if '"@content.downloadUrl"' in text:
            return json.loads(text)["@content.downloadUrl"]
    raise RuntimeError("No @content.downloadUrl found in capture")


def download(url: str, output: Path) -> None:
    req = Request(url, headers={"User-Agent": "Mozilla/5.0"})
    with urlopen(req, timeout=60) as resp:
        output.write_bytes(resp.read())


def shared_strings(zf: zipfile.ZipFile) -> list[str]:
    if "xl/sharedStrings.xml" not in zf.namelist():
        return []
    values = []
    with zf.open("xl/sharedStrings.xml") as f:
        for event, elem in iterparse(f, events=("end",)):
            if elem.tag == f"{{{NS['main']}}}si":
                parts = []
                for t in elem.iter(f"{{{NS['main']}}}t"):
                    parts.append(t.text or "")
                values.append("".join(parts))
                elem.clear()
    return values


def first_sheet_path(zf: zipfile.ZipFile) -> str:
    workbook = zf.read("xl/workbook.xml")
    first_sheet = re.search(rb'<sheet[^>]+r:id="([^"]+)"', workbook)
    if not first_sheet:
        return "xl/worksheets/sheet1.xml"
    rel_id = first_sheet.group(1).decode()
    rels = zf.read("xl/_rels/workbook.xml.rels")
    pattern = rb'<Relationship[^>]+Id="' + re.escape(rel_id.encode()) + rb'"[^>]+Target="([^"]+)"'
    target = re.search(pattern, rels)
    if not target:
        return "xl/worksheets/sheet1.xml"
    path = html.unescape(target.group(1).decode())
    if path.startswith("/"):
        return path.lstrip("/")
    return "xl/" + path


def column_number(cell_ref: str) -> int:
    letters = re.match(r"[A-Z]+", cell_ref).group(0)
    n = 0
    for ch in letters:
        n = n * 26 + ord(ch) - ord("A") + 1
    return n


def xlsx_to_csv(xlsx_path: Path, csv_path: Path) -> None:
    with zipfile.ZipFile(xlsx_path) as zf, csv_path.open("w", newline="", encoding="utf-8") as out:
        strings = shared_strings(zf)
        sheet = first_sheet_path(zf)
        writer = csv.writer(out)
        row_values = []
        current_row = None
        current_cell = None
        current_type = None
        value = None
        inline_parts = []

        with zf.open(sheet) as f:
            for event, elem in iterparse(f, events=("start", "end")):
                tag = elem.tag
                if event == "start" and tag == f"{{{NS['main']}}}row":
                    current_row = int(elem.attrib.get("r", "0"))
                    row_values = []
                elif event == "start" and tag == f"{{{NS['main']}}}c":
                    current_cell = elem.attrib.get("r", "")
                    current_type = elem.attrib.get("t")
                    value = None
                    inline_parts = []
                elif event == "end" and tag == f"{{{NS['main']}}}v":
                    value = elem.text or ""
                elif event == "end" and tag == f"{{{NS['main']}}}t" and current_type == "inlineStr":
                    inline_parts.append(elem.text or "")
                elif event == "end" and tag == f"{{{NS['main']}}}c":
                    col = column_number(current_cell)
                    while len(row_values) < col - 1:
                        row_values.append("")
                    if current_type == "s" and value not in (None, ""):
                        row_values.append(strings[int(value)])
                    elif current_type == "inlineStr":
                        row_values.append("".join(inline_parts))
                    else:
                        row_values.append(value or "")
                    elem.clear()
                elif event == "end" and tag == f"{{{NS['main']}}}row":
                    writer.writerow(row_values)
                    elem.clear()


def main() -> None:
    capture_path = Path(sys.argv[1] if len(sys.argv) > 1 else "iframe_capture2.json")
    xlsx_path = Path(sys.argv[2] if len(sys.argv) > 2 else "elo.xlsx")
    csv_path = Path(sys.argv[3] if len(sys.argv) > 3 else "elo.csv")
    url = metadata_download_url(capture_path)
    download(url, xlsx_path)
    xlsx_to_csv(xlsx_path, csv_path)
    print(f"downloaded={xlsx_path.stat().st_size} bytes csv={csv_path.stat().st_size} bytes")


if __name__ == "__main__":
    main()