#!/usr/bin/env python3
"""Pre-mark channels as skip in manifest.json using a JSON preset file."""

from __future__ import annotations

import json
import sys
from datetime import datetime, timezone
from pathlib import Path

REPO_ROOT = Path(__file__).resolve().parents[1]
MANIFEST_PATH = REPO_ROOT / "manifest.json"
DEFAULT_PRESET = REPO_ROOT / "presets" / "levkin-skips.json"
DEFAULT_EXPORT = Path.home() / "Downloads/Levkin Slack export enriched"


def load_preset(path: Path) -> dict:
    data = json.loads(path.read_text(encoding="utf-8"))
    skip_a = set(data.get("tier_a") or [])
    skip_b = set(data.get("tier_b") or [])
    skip_other = set(data.get("other") or [])
    return {
        "skip_all": skip_a | skip_b | skip_other,
        "tier_a": skip_a,
        "tier_b": skip_b,
        "review_priority": data.get("review_priority") or [],
        "review_later": data.get("review_later") or [],
    }


def channel_entry_skip(notes: str) -> dict:
    return {
        "import": False,
        "status": "skip",
        "reviewed": True,
        "import_mode": "all",
        "notes": notes,
        "mattermost_channel": "",
        "mattermost_team": "",
        "messages": {},
    }


def main() -> int:
    export_path = Path(
        sys.argv[1] if len(sys.argv) > 1 and not sys.argv[1].startswith("-") else DEFAULT_EXPORT
    ).expanduser().resolve()
    preset_path = DEFAULT_PRESET
    for i, arg in enumerate(sys.argv[1:], 1):
        if arg == "--preset" and i < len(sys.argv) - 1:
            preset_path = Path(sys.argv[i + 1]).expanduser().resolve()

    if not export_path.is_dir():
        print(f"Export not found: {export_path}", file=sys.stderr)
        return 1
    if not preset_path.is_file():
        print(f"Preset not found: {preset_path}", file=sys.stderr)
        return 1

    preset = load_preset(preset_path)
    skip_all = preset["skip_all"]

    channels_json = export_path / "channels.json"
    if not channels_json.is_file():
        print(f"No channels.json in {export_path}", file=sys.stderr)
        return 1

    all_names = {c["name"] for c in json.loads(channels_json.read_text()) if c.get("name")}
    for d in export_path.iterdir():
        if d.is_dir() and any(d.glob("*.json")):
            all_names.add(d.name)

    manifest: dict = {
        "version": 1,
        "export_path": str(export_path),
        "updated_at": datetime.now(tz=timezone.utc).isoformat(),
        "global_notes": f"Preset skips from {preset_path.name}",
        "channels": {},
        "users": {},
    }

    if MANIFEST_PATH.is_file():
        existing = json.loads(MANIFEST_PATH.read_text(encoding="utf-8"))
        if isinstance(existing.get("users"), dict):
            manifest["users"] = existing["users"]
        for name, entry in (existing.get("channels") or {}).items():
            if name not in skip_all and isinstance(entry, dict):
                manifest["channels"][name] = entry

    skipped = []
    for name in sorted(skip_all):
        if name in all_names or (export_path / name).is_dir():
            tier = (
                "tier-a"
                if name in preset["tier_a"]
                else "tier-b"
                if name in preset["tier_b"]
                else "other"
            )
            manifest["channels"][name] = channel_entry_skip(
                f"Preset skip ({tier})"
            )
            skipped.append(name)

    undecided = [
        n
        for n in sorted(all_names)
        if n not in skip_all and n not in manifest["channels"]
    ]

    MANIFEST_PATH.write_text(
        json.dumps(manifest, indent=2, ensure_ascii=False) + "\n",
        encoding="utf-8",
    )

    print(f"Wrote {MANIFEST_PATH}")
    print(f"  Skipped ({len(skipped)}): {', '.join('#' + n for n in skipped)}")
    print(f"  Still undecided ({len(undecided)}): {', '.join('#' + n for n in undecided)}")
    print("\nSuggested review order:")
    for n in preset["review_priority"]:
        if n in undecided:
            print(f"  → #{n}")
    for n in sorted(preset["review_later"]):
        if n in undecided:
            print(f"  (later) #{n}")
    return 0


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