#!/usr/bin/env python3
"""Sync docs/TASKS.md rows into .mosaic/orchestrator/tasks.json."""

from __future__ import annotations

import argparse
import json
import os
import pathlib
from typing import Any


def load_json(path: pathlib.Path, default: Any) -> Any:
    if not path.exists():
        return default
    with path.open("r", encoding="utf-8") as f:
        return json.load(f)


def save_json(path: pathlib.Path, data: Any) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    tmp = path.with_suffix(path.suffix + ".tmp")
    with tmp.open("w", encoding="utf-8") as f:
        json.dump(data, f, indent=2)
        f.write("\n")
    tmp.replace(path)


def split_pipe_row(line: str) -> list[str]:
    row = line.strip()
    if row.startswith("|"):
        row = row[1:]
    if row.endswith("|"):
        row = row[:-1]
    return [c.strip() for c in row.split("|")]


def parse_tasks_markdown(path: pathlib.Path) -> list[dict[str, str]]:
    if not path.exists():
        return []
    lines = path.read_text(encoding="utf-8").splitlines()

    header_idx = -1
    headers: list[str] = []
    for i, line in enumerate(lines):
        if "|" not in line:
            continue
        cells = [x.lower() for x in split_pipe_row(line)]
        if "id" in cells and "status" in cells and "description" in cells:
            header_idx = i
            headers = cells
            break
    if header_idx < 0:
        return []

    rows: list[dict[str, str]] = []
    for line in lines[header_idx + 2 :]:
        if not line.strip().startswith("|"):
            if rows:
                break
            continue
        cells = split_pipe_row(line)
        if len(cells) < len(headers):
            cells += [""] * (len(headers) - len(cells))
        row = {headers[i]: cells[i] for i in range(len(headers))}
        task_id = row.get("id", "").strip()
        if not task_id or task_id.lower() == "id":
            continue
        rows.append(row)
    return rows


def map_status(raw: str) -> str:
    value = raw.strip().lower()
    mapping = {
        "not-started": "pending",
        "todo": "pending",
        "pending": "pending",
        "in-progress": "pending",
        "needs-qa": "pending",
        "done": "completed",
        "completed": "completed",
        "failed": "failed",
    }
    return mapping.get(value, "pending")


def parse_depends(raw: str) -> list[str]:
    return [x.strip() for x in raw.split(",") if x.strip()]


def build_task(
    row: dict[str, str],
    existing: dict[str, Any],
    runtime_default: str,
    source_path: str,
) -> dict[str, Any]:
    task_id = row.get("id", "").strip()
    description = row.get("description", "").strip()
    issue = row.get("issue", "").strip()
    repo = row.get("repo", "").strip()
    branch = row.get("branch", "").strip()
    depends_on = parse_depends(row.get("depends_on", ""))

    task = dict(existing)
    task["id"] = task_id
    task["title"] = description or task_id
    task["description"] = description
    task["status"] = map_status(row.get("status", "pending"))
    task["depends_on"] = depends_on
    task["runtime"] = str(task.get("runtime") or runtime_default or "codex")
    task["command"] = str(task.get("command") or "")
    task["quality_gates"] = task.get("quality_gates") or []
    metadata = dict(task.get("metadata") or {})
    metadata.update(
        {
            "source": source_path,
            "issue": issue,
            "repo": repo,
            "branch": branch,
        }
    )
    task["metadata"] = metadata
    return task


def main() -> int:
    parser = argparse.ArgumentParser(description="Sync docs/TASKS.md into .mosaic/orchestrator/tasks.json")
    parser.add_argument("--repo", default=os.getcwd(), help="Repository root (default: cwd)")
    parser.add_argument("--docs", default="docs/TASKS.md", help="Path to tasks markdown (repo-relative)")
    parser.add_argument(
        "--tasks-json",
        default=".mosaic/orchestrator/tasks.json",
        help="Path to orchestrator tasks JSON (repo-relative)",
    )
    parser.add_argument("--keep-unlisted", action="store_true", help="Retain tasks already in JSON but missing from docs/TASKS.md")
    parser.add_argument("--apply", action="store_true", help="Write changes (default is dry-run)")
    args = parser.parse_args()

    repo = pathlib.Path(args.repo).resolve()
    docs_path = (repo / args.docs).resolve()
    # Backward compatibility: fall back to legacy lowercase path when default path is absent.
    if args.docs == "docs/TASKS.md" and not docs_path.exists():
        legacy_docs_path = (repo / "docs/tasks.md").resolve()
        if legacy_docs_path.exists():
            docs_path = legacy_docs_path
    tasks_path = (repo / args.tasks_json).resolve()
    config_path = repo / ".mosaic" / "orchestrator" / "config.json"
    config = load_json(config_path, {})
    runtime_default = str(config.get("worker", {}).get("runtime") or "codex")

    rows = parse_tasks_markdown(docs_path)
    try:
        source_path = str(docs_path.relative_to(repo))
    except ValueError:
        source_path = str(docs_path)
    existing_payload = load_json(tasks_path, {"tasks": []})
    existing_tasks = existing_payload.get("tasks", [])
    if not isinstance(existing_tasks, list):
        existing_tasks = []
    existing_by_id = {str(t.get("id", "")): t for t in existing_tasks}

    out_tasks: list[dict[str, Any]] = []
    seen: set[str] = set()
    for row in rows:
        task_id = row.get("id", "").strip()
        if not task_id:
            continue
        seen.add(task_id)
        out_tasks.append(
            build_task(
                row,
                existing_by_id.get(task_id, {}),
                runtime_default,
                source_path,
            )
        )

    if args.keep_unlisted:
        for task in existing_tasks:
            task_id = str(task.get("id", ""))
            if task_id and task_id not in seen:
                out_tasks.append(task)

    payload = {"tasks": out_tasks}
    if args.apply:
        save_json(tasks_path, payload)
        print(f"[mosaic-orchestrator-sync] wrote {len(out_tasks)} tasks -> {tasks_path}")
    else:
        print(f"[mosaic-orchestrator-sync] dry-run: {len(out_tasks)} tasks would be written -> {tasks_path}")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())