"""Initial tamq command-line surface."""

from __future__ import annotations

import argparse
import asyncio
import json
import os
import signal
import sqlite3
import fcntl
from uuid import uuid4
import subprocess
import sys
import time
from datetime import datetime, timedelta, timezone
from pathlib import Path

from . import __version__
from .config import db_path, pid_path, lock_path, config_path, socket_path, state_dir, setting
from .service import Service, ping, request
from .store import Store
from .tmux import TmuxError, TmuxManager
from .broker import BrokerIdentity, InputBroker
from .ptytap import PtyTap
from .control import ControlModeClient
from .diagnostics import configure
from .policy import load_profile
from .registry import RegistryError, validate_targets
from .terminal import format_comment


SUBCOMMANDS = frozenset(
    "start attach serve stop status ping inbox history inspect ack send export replay purge completion db-version config tap".split()
)
START_OPTIONS = frozenset({"--command", "--cmd", "--tap", "--detach", "--no-service", "--no-display"})
GLOBAL_FLAGS = frozenset({"--orwell", "--verbose"})


def parse_size(value: str) -> int:
    units = {"B": 1, "KB": 1000, "MB": 1000**2, "GB": 1000**3}
    text = value.upper()
    for unit, multiplier in sorted(units.items(), key=lambda item: -len(item[0])):
        if text.endswith(unit):
            return int(float(text[:-len(unit)]) * multiplier)
    return int(text)


def history_advisory(store: Store) -> str | None:
    size, oldest = store.history_stats()
    limit_text = setting("history_max_size", "100MB")
    limit = parse_size(limit_text)
    if size <= limit:
        return None
    since = time.strftime("%y%m%d", time.localtime(oldest)) if oldest else "unknown"
    return f"Size of history is {size / 1000**2:.0f} MB since {since}, exceeding {limit_text}. Consider using 'tamq purge'."


def ensure_service() -> bool:
    if asyncio.run(ping()):
        return True
    path = lock_path()
    path.parent.mkdir(parents=True, exist_ok=True)
    with path.open("a+") as lock:
        fcntl.flock(lock.fileno(), fcntl.LOCK_EX)
        if asyncio.run(ping()):
            return True
        subprocess.Popen(
            [sys.executable, "-m", "tamq.cli", "serve"],
            stdin=subprocess.DEVNULL,
            stdout=subprocess.DEVNULL,
            stderr=subprocess.DEVNULL,
            start_new_session=True,
            env=os.environ.copy(),
        )
        for _ in range(20):
            if asyncio.run(ping()):
                return True
            time.sleep(0.05)
    return False


def stop_service_process() -> int | None:
    try:
        pid = int(pid_path().read_text(encoding="utf-8"))
    except (FileNotFoundError, ValueError):
        return None
    try:
        os.kill(pid, signal.SIGTERM)
    except ProcessLookupError:
        pid_path().unlink(missing_ok=True)
        return None
    deadline = time.monotonic() + 2.0
    while time.monotonic() < deadline:
        try:
            os.kill(pid, 0)
        except ProcessLookupError:
            break
        time.sleep(0.05)
    return pid


def ensure_service_capabilities(required: set[str]) -> bool:
    """Restart an older broker once before registering a newer endpoint mode."""
    if not ensure_service():
        return False
    try:
        capabilities = asyncio.run(request({"op": "ping"})).get("capabilities", [])
    except (OSError, json.JSONDecodeError):
        return False
    if required.issubset(capabilities):
        return True
    stop_service_process()
    if not ensure_service():
        return False
    try:
        capabilities = asyncio.run(request({"op": "ping"})).get("capabilities", [])
    except (OSError, json.JSONDecodeError):
        return False
    return required.issubset(capabilities)


def ensure_manual_service() -> bool:
    return ensure_service_capabilities({"manual_delivery"})


def ensure_output_service() -> bool:
    return ensure_service_capabilities({"manual_delivery", "terminal_output"})


def preflight_runtime_paths() -> None:
    """Ensure local state/runtime parents are available before tmux mutation."""
    parents = {db_path().parent, socket_path().parent, pid_path().parent, lock_path().parent}
    for parent in parents:
        parent.mkdir(parents=True, exist_ok=True)
        if not os.access(parent, os.W_OK | os.X_OK):
            raise OSError(f"runtime directory is not writable: {parent}")


def attach_session(session: str) -> int:
    command = ["tmux", "switch-client" if os.environ.get("TMUX") else "attach-session", "-t", session]
    return subprocess.run(command, check=False).returncode


def format_comment_message(row: sqlite3.Row) -> str:
    """Render a durable message so every displayed line remains a shell comment."""
    return format_comment(row["sender_repo"], row["body"], row["message_id"])


def build_parser() -> argparse.ArgumentParser:
    parser = argparse.ArgumentParser(
        prog="tamq",
        description="Repository-aware tmux sessions with durable local messaging.",
        formatter_class=argparse.RawDescriptionHelpFormatter,
        epilog="""session shorthand:
  tamq [--detach] [--command COMMAND] [--no-display] REPO [REPO ...]

  With no --command, tamq opens ordinary repository shells. --command is an
  explicit initial command for newly created windows. Messages appear as
  sanitized terminal output by default; --no-display keeps them inbox-only.
  Neither mode injects message bytes into pane input.

manual messaging from a managed shell:
  @TARGET: MESSAGE...
  tamq inbox [--filter COMMAND]
""",
    )
    parser.add_argument("--version", "-V", action="version", version=__version__)
    parser.add_argument("--orwell", action="store_true", help="enable unsafe local diagnostics")
    parser.add_argument("--verbose", action="store_true", help="enable debug diagnostics")
    parser.add_argument("--policy-profile", default=None, help="select configured policy profile")
    subparsers = parser.add_subparsers(dest="command")

    start = subparsers.add_parser("start", help="start or reuse a tamq endpoint")
    start.add_argument("repos", nargs="*", help="gita-registered repository slugs")
    start.add_argument("--command", "--cmd", dest="initial_command", default=None, help="explicit initial command for newly created windows (default: ordinary shell)")
    start.add_argument("--tap", action="store_true", help="explicitly opt in to PTY input observation and pane message injection")
    start.add_argument("--no-display", action="store_true", help="keep messages in the durable inbox without writing target terminal output")
    start.add_argument("--detach", action="store_true", help="detach after startup")
    start.add_argument("--no-service", action="store_true", help="open tmux windows without service registration or messaging")
    attach = subparsers.add_parser("attach", help="attach to the managed tmux session")
    attach.add_argument("--session", default="tamq", help="tmux session name")

    subparsers.add_parser("serve", help="run the local service in the foreground")
    subparsers.add_parser("stop", help="stop the local service")
    subparsers.add_parser("status", help="show endpoint health")
    subparsers.add_parser("ping", help="check local service liveness")
    history = subparsers.add_parser("history", help="inspect local message history")
    history.add_argument("--repo", dest="target_repo")
    history.add_argument("--state")
    inbox = subparsers.add_parser("inbox", help="show durable messages for a repository without injecting terminal input")
    inbox.add_argument("--repo", dest="target_repo", help="target repository (default: TAMQ_REPO in a managed window)")
    inbox.add_argument("--all", action="store_true", help="include non-pending messages")
    inbox.add_argument("--json", action="store_true", help="emit one JSON object per message")
    inbox.add_argument(
        "--filter",
        dest="filter_command",
        help="consume each pending comment through COMMAND and acknowledge it after a zero exit",
    )
    inspect = subparsers.add_parser("inspect", help="inspect one message")
    inspect.add_argument("message_id")
    ack = subparsers.add_parser("ack", help="acknowledge one durable message")
    ack.add_argument("message_id")
    send = subparsers.add_parser("send", help="queue a direct message")
    send.add_argument("address", help="@repo: message")
    send.add_argument("body", nargs="*", help="message body when address is a repo slug")
    send.add_argument("--endpoint-id")
    send.add_argument("--from", dest="sender_repo", help="sender repository (default: TAMQ_REPO or local)")
    export = subparsers.add_parser("export", help="export history as JSONL")
    export.add_argument("--output", required=True)
    export.add_argument("--repo", dest="target_repo")
    export.add_argument("--state")
    replay = subparsers.add_parser("replay", help="replay a JSONL message file")
    replay.add_argument("file")
    replay.add_argument("--endpoint-id", help="target a registered tmux-amq endpoint")
    purge = subparsers.add_parser("purge", help="dry-run or remove history")
    purge.add_argument("--before", default=None)
    purge.add_argument("--max-size", default=None)
    purge.add_argument("--yes", action="store_true")
    purge.add_argument("--orwell", action="store_true")
    completion = subparsers.add_parser("completion", help="emit shell completion script")
    completion.add_argument("shell", choices=("bash", "zsh", "fish"))
    subparsers.add_parser("db-version", help="show SQLite schema version")
    subparsers.add_parser("config", help="show effective configuration paths and policy")
    tap = subparsers.add_parser("tap", help="explicitly run a command behind the full-duplex PTY tap")
    tap.add_argument("--repo", required=True, help="source gita repository slug")
    tap.add_argument("--endpoint", required=True, help="tmux-amq endpoint identity")
    tap.add_argument("wrapped_command", nargs=argparse.REMAINDER, help="command after --")
    return parser


def normalize_argv(argv: list[str]) -> list[str]:
    """Allow repository-first startup while retaining explicit subcommands."""
    if not argv:
        return argv
    index = 0
    while index < len(argv):
        token = argv[index]
        if token in GLOBAL_FLAGS or token.startswith("--policy-profile="):
            index += 1
            continue
        if token == "--policy-profile" and index + 1 < len(argv):
            index += 2
            continue
        break
    if index == len(argv):
        return argv
    candidate = argv[index]
    if candidate in START_OPTIONS or (
        not candidate.startswith("-") and candidate not in SUBCOMMANDS
    ):
        return [*argv[:index], "start", *argv[index:]]
    return argv


def main(argv: list[str] | None = None) -> int:
    parser = build_parser()
    raw_argv = list(sys.argv[1:] if argv is None else argv)
    args = parser.parse_args(normalize_argv(raw_argv))
    configure(args.orwell, args.verbose)
    try:
        profile = load_profile(selected=args.policy_profile or os.environ.get("TAMQ_POLICY_PROFILE", "default"))
    except ValueError as exc:
        print(f"tamq: {exc}", file=sys.stderr)
        return 2
    if args.command is None:
        parser.print_help()
        return 0
    if args.command == "db-version":
        store = Store(db_path()); print(store.db.execute("SELECT value FROM metadata WHERE key='schema_version'").fetchone()[0]); store.close(); return 0
    if args.command == "ping":
        return 0 if asyncio.run(ping()) else 1
    if args.command == "stop":
        pid = stop_service_process()
        if pid is not None:
            print(f"stopped tamq service {pid}")
            return 0
        print("tamq service is not running", file=sys.stderr)
        return 1
    if args.command == "serve":
        try: asyncio.run(Service().run())
        except KeyboardInterrupt: return 0
        return 0
    if args.command == "attach":
        return attach_session(args.session)
    if args.command == "completion":
        print(completion_script(args.shell), end="")
        return 0
    if args.command == "config":
        print(json.dumps({"config": str(config_path()), "state_dir": str(state_dir()), "database": str(db_path()), "socket": str(socket_path()), "pidfile": str(pid_path()), "lockfile": str(lock_path()), "policy_profile": profile.name, "delivery_ack_mode": profile.delivery_ack_mode}, sort_keys=True))
        return 0
    if args.command == "tap":
        command = list(args.wrapped_command)
        if command and command[0] == "--":
            command = command[1:]
        if not command:
            print("tamq tap requires a command after --", file=sys.stderr)
            return 2
        store = Store(db_path())
        try:
            return PtyTap(command, InputBroker(store, BrokerIdentity(args.endpoint, args.repo))).run()
        finally:
            store.close()
    if args.command == "start":
        if args.tap and args.initial_command is None:
            print("tamq: --tap requires an explicit --command", file=sys.stderr)
            return 2
        if args.tap and args.no_service:
            print("tamq: --tap cannot be combined with --no-service", file=sys.stderr)
            return 2
        if args.tap and args.no_display:
            print("tamq: --tap cannot be combined with --no-display", file=sys.stderr)
            return 2
        manager = TmuxManager()
        try:
            if not args.no_service:
                preflight_runtime_paths()
            launch_plan = manager.preflight(args.repos, args.initial_command)
        except (TmuxError, OSError) as exc:
            print(f"tamq: {exc}", file=sys.stderr)
            return 2
        service_ready = (
            ensure_manual_service() if args.no_display else ensure_output_service()
        ) if not args.no_service else True
        if not service_ready:
            print("tamq service failed to start with the required delivery capability; use --no-service to open repos without messaging", file=sys.stderr)
            return 1
        try:
            endpoint = manager.ensure_plan(launch_plan, tap=args.tap)
        except (TmuxError, OSError) as exc:
            print(f"tamq: {exc}", file=sys.stderr)
            return 2
        delivered = 0
        registered = False
        if not args.no_service:
            try:
                delivery_mode = "pane" if args.tap else ("manual" if args.no_display else "output")
                registration = asyncio.run(request({"op": "register", "endpoint_id": endpoint.endpoint_id, "instance_id": endpoint.instance_key, "pid": endpoint.pid, "session": endpoint.session, "repos": endpoint.repos, "delivery_mode": delivery_mode}))
                if not registration.get("ok"):
                    raise RuntimeError(f"endpoint registration failed: {registration.get('error', 'unknown error')}")
                registered = True
                if args.tap:
                    control = ControlModeClient(endpoint.session)
                    queue_store = Store(db_path())
                    try:
                        control.start()
                        delivered = InputBroker(queue_store, BrokerIdentity(endpoint.instance_key, endpoint.repos[0])).deliver_pending(
                            control, window_for_repo=lambda repo: f"{endpoint.session}:{repo}"
                        )
                    finally:
                        control.close()
                        queue_store.close()
            except (OSError, RuntimeError, ValueError, json.JSONDecodeError) as exc:
                manager.rollback(endpoint)
                print(f"tamq: {exc}", file=sys.stderr)
                return 1
        summary = {
            "endpoint_id": endpoint.endpoint_id,
            "instance_id": endpoint.instance_key,
            "session": endpoint.session,
            "repos": endpoint.repos,
            "delivered": delivered,
            "service": not args.no_service,
            "messaging": registered,
            "delivery_mode": "none" if args.no_service else ("pane" if args.tap else ("manual" if args.no_display else "output")),
        }
        print(json.dumps(summary), flush=True)
        if args.detach:
            return 0
        return attach_session(endpoint.session)
    store = Store(db_path())
    try:
        advisory = history_advisory(store)
        if advisory and args.command in {"start", "serve", "status", "history", "inbox", "send"}:
            print(advisory, file=sys.stderr)
        if args.command == "send":
            text = " ".join([args.address, *args.body]).strip()
            if not text.startswith("@") or ":" not in text:
                print("tamq send expects @repo: message", file=sys.stderr); return 2
            target, body = text[1:].split(":", 1); body = body.strip()
            if not target or not body: print("tamq send requires a target and body", file=sys.stderr); return 2
            sender = args.sender_repo or os.environ.get("TAMQ_REPO") or "local"
            try:
                validate_targets([target])
                if sender != "local":
                    validate_targets([sender])
            except RegistryError as exc:
                print(f"tamq: {exc}", file=sys.stderr); return 2
            if asyncio.run(ping()):
                payload = {"op": "send", "sender_repo": sender, "target_repo": target, "body": body}
                if args.endpoint_id:
                    payload["endpoint_id"] = args.endpoint_id
                response = asyncio.run(request(payload))
                if not response.get("ok"):
                    print(f"tamq: {response.get('error', 'send failed')}", file=sys.stderr); return 1
                print(response["message_id"]); return 0
            if args.endpoint_id:
                print("tamq: service is not running", file=sys.stderr); return 1
            try:
                print(store.add(sender, target, body))
            except ValueError as exc:
                print(f"tamq: {exc}", file=sys.stderr); return 2
            return 0
        if args.command == "inbox":
            target = args.target_repo or os.environ.get("TAMQ_REPO")
            if not target:
                print("tamq inbox requires --repo outside a managed tamq window", file=sys.stderr)
                return 2
            try:
                validate_targets([target])
            except RegistryError as exc:
                print(f"tamq: {exc}", file=sys.stderr); return 2
            if args.filter_command is not None and not args.filter_command.strip():
                print("tamq: --filter command must not be empty", file=sys.stderr)
                return 2
            if args.filter_command and (args.all or args.json):
                print("tamq: --filter cannot be combined with --all or --json", file=sys.stderr)
                return 2
            rows = store.list(target, None if args.all else "pending")
            for row in rows:
                if args.json:
                    print(json.dumps(dict(row), sort_keys=True))
                elif args.filter_command:
                    environment = os.environ.copy()
                    environment.update(
                        {
                            "TAMQ_MESSAGE_ID": row["message_id"],
                            "TAMQ_SENDER_REPO": row["sender_repo"],
                            "TAMQ_TARGET_REPO": row["target_repo"],
                        }
                    )
                    result = subprocess.run(
                        args.filter_command,
                        shell=True,
                        input=format_comment_message(row) + "\n",
                        text=True,
                        env=environment,
                        check=False,
                    )
                    if result.returncode:
                        print(
                            f"tamq: filter failed for {row['message_id']} with exit status {result.returncode}; message remains pending",
                            file=sys.stderr,
                        )
                        return 1
                    store.acknowledge(row["message_id"])
                else:
                    print(format_comment_message(row))
            return 0
        if args.command == "history":
            for row in store.list(args.target_repo, args.state): print(json.dumps(dict(row), sort_keys=True))
            return 0
        if args.command == "inspect":
            rows = [row for row in store.list() if row["message_id"] == args.message_id]
            if not rows:
                print("tamq: message not found", file=sys.stderr)
                return 1
            print(json.dumps(dict(rows[0]), sort_keys=True)); return 0
        if args.command == "ack":
            if not store.acknowledge(args.message_id):
                print("tamq: message not found", file=sys.stderr); return 1
            print(args.message_id); return 0
        if args.command == "export":
            store.export(store.list(args.target_repo, args.state), Path(args.output)); return 0
        if args.command == "replay":
            batch_id = f"replay-{uuid4()}"
            count = 0
            if args.endpoint_id and store.endpoint(args.endpoint_id) is None:
                print(f"tamq: endpoint is not registered: {args.endpoint_id}", file=sys.stderr)
                return 1
            try:
                lines = Path(args.file).read_text(encoding="utf-8").splitlines()
                for line in lines:
                    if not line.strip():
                        continue
                    item = json.loads(line)
                    provenance = json.dumps({"batch_id": batch_id, "original_message_id": item.get("message_id")}, sort_keys=True)
                    endpoint = args.endpoint_id or item.get("endpoint_id")
                    store.add(item.get("sender_repo", "replay"), item["target_repo"], item["body"], endpoint=endpoint, provenance=provenance)
                    count += 1
            except (OSError, KeyError, TypeError, ValueError, json.JSONDecodeError) as exc:
                print(f"tamq: cannot replay {args.file}: {exc}", file=sys.stderr)
                return 2
            print(json.dumps({"batch_id": batch_id, "count": count})); return 0
        if args.command == "purge":
            before_text = args.before or setting("purge_before", "365d")
            max_size_text = args.max_size or setting("purge_max_size", "100MB")
            before = time.time() - int(before_text[:-1]) * 86400 if before_text.endswith("d") else None
            if not args.yes:
                matching = [row for row in store.list() if before is None or row["created_at"] < before]
                print(f"Dry run: {len(matching)} message(s) match; re-run with --yes to purge.")
                return 0
            count = store.purge(before=before, max_bytes=parse_size(max_size_text))
            print(f"Purged {count} message(s)."); return 0
        if args.command == "status":
            live = asyncio.run(ping())
            endpoints = asyncio.run(request({"op": "endpoints"})) if live else {"endpoints": []}
            print(json.dumps({"version": __version__, "db": str(db_path()), "messages": len(store.list()), "pending": len(store.list(state="pending")), "leases": store.db.execute("SELECT COUNT(*) FROM leases").fetchone()[0], "service": live, "policy_profile": profile.name, "delivery_ack_mode": profile.delivery_ack_mode, "endpoints": endpoints.get("endpoints", [])}, sort_keys=True)); return 0
        print(f"tamq {__version__}: command '{args.command}' is not implemented yet", file=sys.stderr)
        return 2
    finally:
        store.close()


def completion_script(shell: str) -> str:
    commands = " ".join(sorted(SUBCOMMANDS))
    if shell == "bash":
        return f"""_tamq_complete() {{
  local commands=\"{commands}\"
  if [[ ${{COMP_WORDS[1]}} == start || ${{COMP_WORDS[1]}} == send ]]; then
    COMPREPLY=( $(compgen -W \"$(gita ls 2>/dev/null)\" -- \"${{COMP_WORDS[COMP_CWORD]}}\") )
  else
    COMPREPLY=( $(compgen -W \"$commands\" -- \"${{COMP_WORDS[COMP_CWORD]}}\") )
  fi
}}
complete -F _tamq_complete tamq
"""
    if shell == "zsh":
        return f"#compdef tamq\n_arguments '1:command:(({commands}))' '*:repo:->repos'\nif [[ $state == repos ]]; then _values 'gita repo' $(gita ls 2>/dev/null); fi\n"
    return f"complete -c tamq -f -n '__fish_seen_subcommand_from start send' -a '(gita ls 2>/dev/null)'\ncomplete -c tamq -f -a '{commands}'\n"


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