#!/usr/bin/env python3
"""
Gitea Issue Body Parser

Extracts structured data from Gitea issue markdown bodies:
- Title
- Context section
- Acceptance criteria (checkboxes)
- Labels
- Epic/parent references

Usage:
  python3 scripts/gitea_issue_parser.py <issue_body.txt
  python3 scripts/gitea_issue_parser.py --url https://forge.../api/v1/repos/.../issues/123
  echo "issue body" | python3 scripts/gitea_issue_parser.py --stdin

Output: JSON with {title, context, criteria[], labels[], epic_ref}
"""

import argparse
import json
import re
import sys
from typing import Optional


def parse_issue_body(body: str, title: str = "", labels: list = None) -> dict:
    """Parse a Gitea issue body into structured JSON."""
    result = {
        "title": title,
        "context": "",
        "criteria": [],
        "labels": labels or [],
        "epic_ref": None,
        "sections": {},
    }

    if not body:
        return result

    # Extract epic/parent reference from title or body
    epic_pattern = r"#(\d+)"
    title_refs = re.findall(epic_pattern, title)
    body_refs = re.findall(epic_pattern, body[:200])  # Check early body refs

    # Look for "Closes #N" or "Part of #N" or "Epic: #N"
    close_match = re.search(r"(?:Closes?|Fixes?|Resolves?)\s+#(\d+)", body, re.IGNORECASE)
    part_match = re.search(r"(?:Part of|Epic|Parent|Blocks?)\s+#(\d+)", body, re.IGNORECASE)

    if close_match:
        result["epic_ref"] = f"#{close_match.group(1)}"
    elif part_match:
        result["epic_ref"] = f"#{part_match.group(1)}"
    elif title_refs:
        result["epic_ref"] = f"#{title_refs[0]}"
    elif body_refs:
        result["epic_ref"] = f"#{body_refs[0]}"

    # Split into sections by ## headers
    section_pattern = r"^##\s+(.+)$"
    lines = body.split("\n")
    current_section = None
    current_content = []

    for line in lines:
        header_match = re.match(section_pattern, line)
        if header_match:
            # Save previous section
            if current_section:
                result["sections"][current_section] = "\n".join(current_content).strip()
            current_section = header_match.group(1).strip().lower()
            current_content = []
        else:
            current_content.append(line)

    # Save last section
    if current_section:
        result["sections"][current_section] = "\n".join(current_content).strip()

    # Extract context
    for key in ["context", "background", "description", "problem"]:
        if key in result["sections"]:
            result["context"] = result["sections"][key]
            break

    # Extract acceptance criteria (checkboxes)
    criteria_section = None
    for key in ["acceptance criteria", "acceptance_criteria", "criteria", "requirements", "definition of done"]:
        if key in result["sections"]:
            criteria_section = result["sections"][key]
            break

    if criteria_section:
        checkbox_pattern = r"-\s*\[[ xX]?\]\s*(.+)"
        for match in re.finditer(checkbox_pattern, criteria_section):
            result["criteria"].append(match.group(1).strip())

        # Also try plain numbered/bulleted lists if no checkboxes found
        if not result["criteria"]:
            list_pattern = r"^\s*(?:\d+\.|-|\*)\s+(.+)"
            for match in re.finditer(list_pattern, criteria_section, re.MULTILINE):
                result["criteria"].append(match.group(1).strip())

    # If no sectioned criteria found, scan whole body for checkboxes
    if not result["criteria"]:
        for match in re.finditer(r"-\s*\[[ xX]?\]\s*(.+)", body):
            result["criteria"].append(match.group(1).strip())

    return result


def parse_from_url(api_url: str, token: str = None) -> dict:
    """Parse an issue from a Gitea API URL."""
    import urllib.request

    headers = {}
    if token:
        headers["Authorization"] = f"token {token}"

    req = urllib.request.Request(api_url, headers=headers)
    resp = json.loads(urllib.request.urlopen(req, timeout=30).read())

    title = resp.get("title", "")
    body = resp.get("body", "")
    labels = [l["name"] for l in resp.get("labels", [])]

    return parse_issue_body(body, title, labels)


def main():
    parser = argparse.ArgumentParser(description="Parse Gitea issue body into structured JSON")
    parser.add_argument("input", nargs="?", help="Issue body file (or - for stdin)")
    parser.add_argument("--url", help="Gitea API URL for the issue")
    parser.add_argument("--stdin", action="store_true", help="Read from stdin")
    parser.add_argument("--token", help="Gitea API token (or set GITEA_TOKEN env var)")
    parser.add_argument("--title", default="", help="Issue title (for epic ref extraction)")
    parser.add_argument("--labels", nargs="*", default=[], help="Issue labels")
    parser.add_argument("--pretty", action="store_true", help="Pretty-print JSON output")
    args = parser.parse_args()

    import os
    token = args.token or os.environ.get("GITEA_TOKEN")

    if args.url:
        result = parse_from_url(args.url, token)
    elif args.stdin or (args.input and args.input == "-"):
        body = sys.stdin.read()
        result = parse_issue_body(body, args.title, args.labels)
    elif args.input:
        with open(args.input) as f:
            body = f.read()
        result = parse_issue_body(body, args.title, args.labels)
    else:
        parser.print_help()
        sys.exit(1)

    indent = 2 if args.pretty else None
    print(json.dumps(result, indent=indent))


if __name__ == "__main__":
    main()