"""Migration routines for SMB and NFS shares."""
from __future__ import annotations

import json
from typing import Any

from .colors import log, _bold, _bold_cyan, _bold_green, _bold_red, _cyan, _yellow
from .client import TrueNASClient
from .summary import Summary


# ─────────────────────────────────────────────────────────────────────────────
# Payload builders
# ─────────────────────────────────────────────────────────────────────────────

# Read-only / server-generated fields that must NOT be sent on create/update
_SMB_SHARE_READONLY = frozenset({"id", "locked"})

# CORE SMB share fields that do not exist in the SCALE API
_SMB_SHARE_CORE_EXTRAS = frozenset({
    "vuid",   # server-generated Time Machine UUID; SCALE sets this automatically
})

# CORE NFS share fields that do not exist in the SCALE API
_NFS_SHARE_CORE_EXTRAS = frozenset({
    "paths",    # CORE uses a list; SCALE uses a single "path" string (converted below)
    "alldirs",  # removed in SCALE
    "quiet",    # removed in SCALE
})


def _smb_share_payload(share: dict) -> dict:
    exclude = _SMB_SHARE_READONLY | _SMB_SHARE_CORE_EXTRAS
    return {k: v for k, v in share.items() if k not in exclude}


def _nfs_share_payload(share: dict) -> dict:
    payload = {k: v for k, v in share.items()
               if k not in {"id", "locked"} | _NFS_SHARE_CORE_EXTRAS}
    # CORE stores export paths as a list under "paths"; SCALE expects a single "path" string.
    if "path" not in payload and share.get("paths"):
        payload["path"] = share["paths"][0]
    return payload


# ─────────────────────────────────────────────────────────────────────────────
# Migration routines
# ─────────────────────────────────────────────────────────────────────────────

async def migrate_smb_shares(
    client: TrueNASClient,
    shares: list[dict],
    dry_run: bool,
    summary: Summary,
) -> None:
    summary.smb_found = len(shares)
    if not shares:
        log.info("No SMB shares found in archive.")
        return

    log.info("Querying existing SMB shares on destination …")
    try:
        existing = await client.call("sharing.smb.query") or []
    except RuntimeError as exc:
        msg = f"Could not query SMB shares: {exc}"
        log.error(msg)
        summary.errors.append(msg)
        return

    existing_names = {s.get("name", "").lower() for s in existing}
    log.info("  Destination has %d existing SMB share(s).", len(existing_names))

    for share in shares:
        name = share.get("name", "<unnamed>")
        log.info("%s SMB share %s", _bold("──"), _bold_cyan(repr(name)))

        if name.lower() in existing_names:
            log.info("   %s – already exists on destination.", _yellow("SKIP"))
            summary.smb_skipped += 1
            continue

        payload = _smb_share_payload(share)
        log.debug("   payload: %s", json.dumps(payload))

        if dry_run:
            log.info("   %s would create %s → %s",
                     _cyan("[DRY RUN]"), _bold_cyan(repr(name)), payload.get("path"))
            summary.smb_created += 1
            if payload.get("path"):
                summary.paths_to_create.append(payload["path"])
            continue

        try:
            r = await client.call("sharing.smb.create", [payload])
            log.info("   %s  id=%s", _bold_green("CREATED"), r.get("id"))
            summary.smb_created += 1
        except RuntimeError as exc:
            log.error("   %s: %s", _bold_red("FAILED"), exc)
            summary.smb_failed += 1
            summary.errors.append(f"SMB share {name!r}: {exc}")


async def migrate_nfs_shares(
    client: TrueNASClient,
    shares: list[dict],
    dry_run: bool,
    summary: Summary,
) -> None:
    summary.nfs_found = len(shares)
    if not shares:
        log.info("No NFS shares found in archive.")
        return

    log.info("Querying existing NFS shares on destination …")
    try:
        existing = await client.call("sharing.nfs.query") or []
    except RuntimeError as exc:
        msg = f"Could not query NFS shares: {exc}"
        log.error(msg)
        summary.errors.append(msg)
        return

    existing_paths = {s.get("path", "").rstrip("/") for s in existing}
    log.info("  Destination has %d existing NFS share(s).", len(existing_paths))

    for share in shares:
        core_paths = share.get("paths") or []
        path = (share.get("path") or (core_paths[0] if core_paths else "")).rstrip("/")
        all_paths = [p.rstrip("/") for p in (core_paths if core_paths else ([path] if path else []))]
        log.info("%s NFS export %s", _bold("──"), _bold_cyan(repr(path)))

        if path in existing_paths:
            log.info("   %s – path already exported on destination.", _yellow("SKIP"))
            summary.nfs_skipped += 1
            continue

        payload = _nfs_share_payload(share)
        log.debug("   payload: %s", json.dumps(payload))

        if dry_run:
            log.info("   %s would create NFS export for %s",
                     _cyan("[DRY RUN]"), _bold_cyan(repr(path)))
            summary.nfs_created += 1
            summary.paths_to_create.extend(all_paths)
            continue

        try:
            r = await client.call("sharing.nfs.create", [payload])
            log.info("   %s  id=%s", _bold_green("CREATED"), r.get("id"))
            summary.nfs_created += 1
        except RuntimeError as exc:
            log.error("   %s: %s", _bold_red("FAILED"), exc)
            summary.nfs_failed += 1
            summary.errors.append(f"NFS share {path!r}: {exc}")