"""
truenas_migrate  –  TrueNAS Share Migration Tool
=================================================
Reads SMB shares and NFS shares from either a TrueNAS debug archive (.tar / .tgz)
or customer-supplied CSV files, then re-creates them on a destination TrueNAS
system via the JSON-RPC 2.0 WebSocket API (TrueNAS 25.04+).

SAFE BY DEFAULT
  • Existing shares are never overwritten or deleted.
  • Always run with --dry-run first to preview what will happen.

REQUIREMENTS
  Python 3.9+ (stdlib only – no external packages needed)

QUICK START — Archive source
  # 1. Inspect your debug archive to confirm it contains the data you need:
  python -m truenas_migrate --debug-tar debug.tgz --list-archive

  # 2. Dry-run – connect to destination but make zero changes:
  python -m truenas_migrate \\
      --debug-tar  debug.tgz \\
      --dest       192.168.1.50 \\
      --api-key    "1-xxxxxxxxxxxx" \\
      --dry-run

  # 3. Live migration:
  python -m truenas_migrate \\
      --debug-tar  debug.tgz \\
      --dest       192.168.1.50 \\
      --api-key    "1-xxxxxxxxxxxx"

QUICK START — CSV source
  # Fill in smb_shares_template.csv / nfs_shares_template.csv, then:
  python -m truenas_migrate \\
      --smb-csv    smb_shares.csv \\
      --nfs-csv    nfs_shares.csv \\
      --dest       192.168.1.50 \\
      --api-key    "1-xxxxxxxxxxxx" \\
      --dry-run

CONFLICT POLICY
  Shares that already exist on the destination are silently skipped:
    SMB  – matched by share name  (case-insensitive)
    NFS  – matched by export path (exact match)
"""
from __future__ import annotations

import argparse
import asyncio
import getpass
import logging
import sys
from pathlib import Path
from typing import Optional

from .archive import parse_archive, list_archive_and_exit
from .client import TrueNASClient, check_dataset_paths, create_missing_datasets
from .colors import log, _bold, _bold_cyan, _bold_red, _bold_yellow, _cyan, _dim, _green, _yellow
from .csv_source import parse_csv_sources
from .migrate import migrate_smb_shares, migrate_nfs_shares
from .summary import Summary


# ─────────────────────────────────────────────────────────────────────────────
# CLI orchestration
# ─────────────────────────────────────────────────────────────────────────────

async def run(
    args: argparse.Namespace,
    archive: Optional[dict] = None,
) -> Summary:
    if archive is None:
        smb_csv = getattr(args, "smb_csv", None)
        nfs_csv = getattr(args, "nfs_csv", None)
        if smb_csv or nfs_csv:
            archive = parse_csv_sources(smb_csv, nfs_csv)
        else:
            archive = parse_archive(args.debug_tar)

    migrate_set = set(args.migrate)

    if args.dry_run:
        msg = "  DRY RUN – no changes will be made on the destination  "
        bar = _bold_yellow("─" * len(msg))
        print(f"\n{_bold_yellow('┌')}{bar}{_bold_yellow('┐')}", file=sys.stderr)
        print(f"{_bold_yellow('│')}{_bold_yellow(msg)}{_bold_yellow('│')}", file=sys.stderr)
        print(f"{_bold_yellow('└')}{bar}{_bold_yellow('┘')}\n", file=sys.stderr)

    summary = Summary()

    async with TrueNASClient(
        host=args.dest,
        port=args.port,
        api_key=args.api_key,
        verify_ssl=args.verify_ssl,
    ) as client:

        if "smb" in migrate_set:
            await migrate_smb_shares(
                client, archive["smb_shares"], args.dry_run, summary)

        if "nfs" in migrate_set:
            await migrate_nfs_shares(
                client, archive["nfs_shares"], args.dry_run, summary)

        if args.dry_run and summary.paths_to_create:
            summary.missing_datasets = await check_dataset_paths(
                client, summary.paths_to_create,
            )

    return summary


# ─────────────────────────────────────────────────────────────────────────────
# Interactive wizard helpers
# ─────────────────────────────────────────────────────────────────────────────

def _find_debug_archives(directory: str = ".") -> list[Path]:
    """Return sorted list of TrueNAS debug archives found in *directory*."""
    patterns = ("*.tgz", "*.tar.gz", "*.tar", "*.txz", "*.tar.xz")
    found: set[Path] = set()
    for pat in patterns:
        found.update(Path(directory).glob(pat))
    return sorted(found)


def _prompt(label: str, default: str = "") -> str:
    suffix = f" [{default}]" if default else ""
    try:
        val = input(f"{label}{suffix}: ").strip()
        return val if val else default
    except (EOFError, KeyboardInterrupt):
        print()
        sys.exit(0)


def _confirm(label: str) -> bool:
    try:
        return input(f"{label} [y/N]: ").strip().lower() in ("y", "yes")
    except (EOFError, KeyboardInterrupt):
        print()
        return False


def _prompt_csv_path(share_type: str) -> Optional[str]:
    """Prompt for a CSV file path.  Returns resolved path string or None if skipped."""
    template = f"{share_type.lower()}_shares_template.csv"
    print(f"  {_dim('(template: ' + template + ')')}")
    while True:
        raw = _prompt(f"  {share_type} shares CSV path (Enter to skip)")
        if not raw:
            return None
        p = Path(raw)
        if p.is_file():
            return str(p)
        print(f"  {_bold_red('File not found:')} {raw}")


def _select_shares(shares: list[dict], share_type: str) -> list[dict]:
    """
    Display a numbered list of *shares* and return only those the user selects.
    Enter (or 'all') returns all shares unchanged.  'n' / 'none' returns [].
    """
    if not shares:
        return shares

    print(f"\n  {_bold(f'{share_type} shares ({len(shares)}):')} \n")
    for i, share in enumerate(shares, 1):
        if share_type == "SMB":
            name = share.get("name", "<unnamed>")
            path = share.get("path", "")
            print(f"    {_cyan(str(i) + '.')}  {name:<22}  {_dim(path)}")
        else:  # NFS
            pl = share.get("paths") or []
            path = share.get("path") or (pl[0] if pl else "")
            extra = f"  {_dim('+ ' + str(len(pl) - 1) + ' more')}" if len(pl) > 1 else ""
            print(f"    {_cyan(str(i) + '.')}  {path}{extra}")

    print()
    raw = _prompt(
        f"  Select {share_type} shares to migrate "
        "(e.g. '1 3', Enter = all, 'n' = none)",
        default="all",
    )

    low = raw.strip().lower()
    if low in ("", "all"):
        print(f"  {_green('✓')} All {len(shares)} {share_type} share(s) selected.")
        return shares
    if low in ("n", "none", "0"):
        print(f"  {_yellow('–')} No {share_type} shares selected.")
        return []

    seen: set[int] = set()
    selected: list[dict] = []
    for tok in raw.split():
        if tok.isdigit():
            idx = int(tok) - 1
            if 0 <= idx < len(shares) and idx not in seen:
                seen.add(idx)
                selected.append(shares[idx])

    if selected:
        print(f"  {_green('✓')} {len(selected)} of {len(shares)} {share_type} share(s) selected.")
    else:
        print(f"  {_yellow('–')} No valid selections; skipping {share_type} shares.")
    return selected


# ─────────────────────────────────────────────────────────────────────────────
# Interactive wizard
# ─────────────────────────────────────────────────────────────────────────────

def interactive_mode() -> None:
    """Interactive wizard: pick source → configure → dry run → confirm → apply."""
    print(
        f"\n{_bold_cyan('  TrueNAS Share Migration Tool')}\n"
        f"  {_dim('Migrate SMB/NFS shares to a live TrueNAS system.')}\n"
    )

    # 1 ── Source type ──────────────────────────────────────────────────────────
    print(f"  {_bold('Source type:')}")
    print(f"  {_cyan('1.')} TrueNAS debug archive  (.tgz / .tar)")
    print(f"  {_cyan('2.')} CSV import  (non-TrueNAS source)")
    src_raw = _prompt("  Select source [1/2]", default="1")
    use_csv = src_raw.strip() == "2"
    print()

    # 2 ── Destination ──────────────────────────────────────────────────────────
    host = ""
    while not host:
        host = _prompt("Destination TrueNAS host or IP")
        if not host:
            print("  Host is required.")

    port_raw = _prompt("WebSocket port", default="443")
    port = int(port_raw) if port_raw.isdigit() else 443

    # 3 ── API key ──────────────────────────────────────────────────────────────
    api_key = ""
    while not api_key:
        try:
            api_key = getpass.getpass("API key (input hidden): ").strip()
        except (EOFError, KeyboardInterrupt):
            print()
            sys.exit(0)
        if not api_key:
            print("  API key is required.")

    if use_csv:
        # ── CSV source ──────────────────────────────────────────────────────────
        print(f"\n  {_bold('CSV file paths:')}")
        print(f"  {_dim('Press Enter to skip a share type.')}\n")
        smb_csv_path = _prompt_csv_path("SMB")
        print()
        nfs_csv_path = _prompt_csv_path("NFS")

        migrate: list[str] = []
        if smb_csv_path:
            migrate.append("smb")
        if nfs_csv_path:
            migrate.append("nfs")
        if not migrate:
            sys.exit("No CSV files provided – nothing to migrate.")

        print()
        archive_data = parse_csv_sources(smb_csv_path, nfs_csv_path)
        extra_ns: dict = {"smb_csv": smb_csv_path, "nfs_csv": nfs_csv_path}

    else:
        # ── Archive source ──────────────────────────────────────────────────────
        archives = _find_debug_archives()
        if not archives:
            sys.exit(
                "No debug archives (.tgz / .tar.gz / .tar / .txz) found in the "
                "current directory.\n"
                "Copy your TrueNAS debug file here, or use --debug-tar to specify a path."
            )

        if len(archives) == 1:
            chosen = archives[0]
            print(f"  {_dim('Archive:')} {_bold(chosen.name)}  "
                  f"{_dim('(' + f'{chosen.stat().st_size / 1_048_576:.1f} MB' + ')')}\n")
        else:
            print(f"  {_bold('Debug archives found:')}\n")
            for i, p in enumerate(archives, 1):
                print(f"  {_cyan(str(i) + '.')} {p.name}  "
                      f"{_dim('(' + f'{p.stat().st_size / 1_048_576:.1f} MB' + ')')}")
            print()
            while True:
                raw = _prompt(f"Select archive [1-{len(archives)}]")
                if raw.isdigit() and 1 <= int(raw) <= len(archives):
                    chosen = archives[int(raw) - 1]
                    break
                print(f"  Enter a number from 1 to {len(archives)}.")

        # ── Migration scope ─────────────────────────────────────────────────────
        print(f"\n  {_bold('What to migrate?')}")
        print(f"  {_cyan('1.')} SMB shares")
        print(f"  {_cyan('2.')} NFS shares")
        sel_raw = _prompt(
            "Selection (space-separated numbers, Enter for all)", default="1 2"
        )
        _sel_map = {"1": "smb", "2": "nfs"}
        migrate = []
        for tok in sel_raw.split():
            if tok in _sel_map and _sel_map[tok] not in migrate:
                migrate.append(_sel_map[tok])
        if not migrate:
            migrate = ["smb", "nfs"]

        # ── Parse archive ───────────────────────────────────────────────────────
        print()
        archive_data = parse_archive(str(chosen))
        extra_ns = {"debug_tar": str(chosen)}

    # ── Select individual shares (common) ──────────────────────────────────────
    if "smb" in migrate and archive_data["smb_shares"]:
        archive_data["smb_shares"] = _select_shares(archive_data["smb_shares"], "SMB")
    if "nfs" in migrate and archive_data["nfs_shares"]:
        archive_data["nfs_shares"] = _select_shares(archive_data["nfs_shares"], "NFS")
    print()

    base_ns = dict(
        dest=host,
        port=port,
        api_key=api_key,
        verify_ssl=False,
        migrate=migrate,
        **extra_ns,
    )

    # 6 ── Dry run ──────────────────────────────────────────────────────────────
    dry_summary = asyncio.run(
        run(argparse.Namespace(**base_ns, dry_run=True), archive_data)
    )
    print(dry_summary.report())

    # Offer to create missing datasets before the live run
    if dry_summary.missing_datasets:
        non_mnt   = [p for p in dry_summary.missing_datasets if not p.startswith("/mnt/")]
        creatable = [p for p in dry_summary.missing_datasets if p.startswith("/mnt/")]

        if non_mnt:
            print(f"  NOTE: {len(non_mnt)} path(s) cannot be auto-created "
                  "(not under /mnt/):")
            for p in non_mnt:
                print(f"    • {p}")
            print()

        if creatable:
            print(f"  {len(creatable)} dataset(s) can be created automatically:")
            for p in creatable:
                print(f"    • {p}")
            print()
            if _confirm(f"Create these {len(creatable)} dataset(s) on {host} now?"):
                asyncio.run(create_missing_datasets(
                    host=host,
                    port=port,
                    api_key=api_key,
                    paths=creatable,
                ))
                print()

    if not _confirm(f"Apply these changes to {host}?"):
        print("Aborted – no changes made.")
        sys.exit(0)

    # 7 ── Live run ─────────────────────────────────────────────────────────────
    print()
    live_summary = asyncio.run(
        run(argparse.Namespace(**base_ns, dry_run=False), archive_data)
    )
    print(live_summary.report())
    if live_summary.errors:
        sys.exit(2)


# ─────────────────────────────────────────────────────────────────────────────
# Argument parser + entry point
# ─────────────────────────────────────────────────────────────────────────────

def main() -> None:
    if len(sys.argv) == 1:
        interactive_mode()
        return

    p = argparse.ArgumentParser(
        prog="truenas_migrate",
        description=(
            "Migrate SMB and NFS shares to a live TrueNAS destination system.  "
            "Source can be a TrueNAS debug archive or customer-supplied CSV files."
        ),
        formatter_class=argparse.RawDescriptionHelpFormatter,
        epilog=__doc__,
    )

    # ── Source ────────────────────────────────────────────────────────────────
    src = p.add_argument_group("source (choose one)")
    src.add_argument(
        "--debug-tar", metavar="FILE",
        help="Path to the TrueNAS debug .tar / .tgz from the SOURCE system.",
    )
    src.add_argument(
        "--smb-csv", metavar="FILE",
        help="Path to a CSV file containing SMB share definitions (non-TrueNAS source).",
    )
    src.add_argument(
        "--nfs-csv", metavar="FILE",
        help="Path to a CSV file containing NFS share definitions (non-TrueNAS source).",
    )
    p.add_argument(
        "--list-archive", action="store_true",
        help=(
            "List all JSON files found in the archive and exit.  "
            "Requires --debug-tar."
        ),
    )

    # ── Destination ───────────────────────────────────────────────────────────
    p.add_argument(
        "--dest", metavar="HOST",
        help="Hostname or IP of the DESTINATION TrueNAS system.",
    )
    p.add_argument(
        "--port", type=int, default=443, metavar="PORT",
        help="WebSocket port on the destination (default: 443).",
    )
    p.add_argument(
        "--verify-ssl", action="store_true",
        help=(
            "Verify the destination TLS certificate. "
            "Off by default because most TrueNAS systems use self-signed certs."
        ),
    )

    # ── Authentication ────────────────────────────────────────────────────────
    p.add_argument(
        "--api-key", metavar="KEY",
        help=(
            "TrueNAS API key.  Generate one in TrueNAS UI: "
            "top-right account menu → API Keys."
        ),
    )

    # ── Scope ─────────────────────────────────────────────────────────────────
    p.add_argument(
        "--migrate",
        nargs="+",
        choices=["smb", "nfs"],
        default=["smb", "nfs"],
        metavar="TYPE",
        help=(
            "What to migrate.  Choices: smb  nfs "
            "(default: both).  Example: --migrate smb"
        ),
    )
    p.add_argument(
        "--dry-run", action="store_true",
        help="Parse source and connect to destination, but make no changes.",
    )
    p.add_argument(
        "--verbose", "-v", action="store_true",
        help="Enable DEBUG-level logging.",
    )

    args = p.parse_args()

    if args.verbose:
        log.setLevel(logging.DEBUG)

    has_archive = bool(args.debug_tar)
    has_csv     = bool(args.smb_csv or args.nfs_csv)

    if has_archive and has_csv:
        p.error("Cannot combine --debug-tar with --smb-csv / --nfs-csv.")

    if not has_archive and not has_csv:
        p.error(
            "Specify a source: --debug-tar FILE  or  --smb-csv / --nfs-csv FILE(s)."
        )

    if has_archive:
        if not Path(args.debug_tar).is_file():
            p.error(f"Archive not found: {args.debug_tar}")
        if args.list_archive:
            list_archive_and_exit(args.debug_tar)   # does not return
    else:
        if args.list_archive:
            p.error("--list-archive requires --debug-tar.")
        if args.smb_csv and not Path(args.smb_csv).is_file():
            p.error(f"SMB CSV not found: {args.smb_csv}")
        if args.nfs_csv and not Path(args.nfs_csv).is_file():
            p.error(f"NFS CSV not found: {args.nfs_csv}")

    if not args.dest:
        p.error("--dest is required.")
    if not args.api_key:
        p.error("--api-key is required.")

    summary = asyncio.run(run(args))
    print(summary.report())
    if summary.errors:
        sys.exit(2)