"""MCP tools for SYNO.Docker.Container: list, status, logs, exec."""

from __future__ import annotations

import json
import logging
import re
from typing import TYPE_CHECKING, Any

if TYPE_CHECKING:
    from mcp.server.fastmcp import FastMCP

    from mcp_synology_container.config import AppConfig
    from mcp_synology_container.dsm_client import DsmClient

logger = logging.getLogger(__name__)

# Matches DSM hash-prefixed container names like "f93cb8b504f7_jenkins"
_HASH_PREFIX_RE = re.compile(r"^[a-f0-9]{12}_(.+)$")


def _strip_hash_prefix(name: str) -> str:
    """Strip 12-char hex hash prefix from container names.

    DSM sometimes returns names like 'f93cb8b504f7_jenkins' when the
    service name in compose.yaml differs from container_name. Returns the
    clean name (also strips a leading slash if present).
    """
    clean = name.lstrip("/")
    match = _HASH_PREFIX_RE.match(clean)
    return match.group(1) if match else clean


async def _resolve_container_name(client: DsmClient, user_name: str) -> str:
    """Resolve a user-supplied name to the actual DSM container name.

    Needed because DSM may store the container as 'f93cb8b504f7_jenkins'
    while the user passes 'jenkins'. Falls back to user_name unchanged if
    the list cannot be fetched or no match is found.

    Args:
        client: DsmClient instance.
        user_name: Name as provided by the user (may or may not have prefix).

    Returns:
        Actual container name as registered in DSM.
    """
    clean_user = _strip_hash_prefix(user_name)
    try:
        data = await client.request(
            "SYNO.Docker.Container",
            "list",
            params={"limit": "-1", "offset": "0", "type": "all"},
        )
        for c in data.get("containers", []):
            actual = c.get("name", "")
            if actual == user_name or _strip_hash_prefix(actual) == clean_user:
                return actual
    except Exception:
        pass
    return user_name


def register_containers(mcp: FastMCP, config: AppConfig, client: DsmClient) -> None:
    """Register all container management tools with the MCP server."""

    @mcp.tool()
    async def list_containers(project_name: str | None = None):
        """List all containers, optionally filtered by project name."""
        try:
            data = await client.request(
                "SYNO.Docker.Container",
                "list",
                params={"limit": "-1", "offset": "0", "type": "all"},
            )
        except Exception as e:
            return f"Error listing containers: {e}"

        containers: list[dict[str, Any]] = data.get("containers", [])
        if not containers:
            return "No containers found."

        # Filter by project if specified
        if project_name:
            containers = [
                c
                for c in containers
                if c.get("project_name") == project_name or _container_in_project(c, project_name)
            ]
            if not containers:
                return f"No containers found for project '{project_name}'."

        lines = [f"Containers ({len(containers)} total):", ""]
        for container in sorted(containers, key=lambda c: c.get("name", "")):
            name = _strip_hash_prefix(container.get("name", "?"))
            state = container.get("status", container.get("state", "?"))
            image = container.get("image", "?")
            lines.append(f"  {name}")
            lines.append(f"    Status: {state}")
            lines.append(f"    Image:  {image}")
            lines.append("")

        return "\n".join(lines).rstrip()

    @mcp.tool()
    async def get_container_status(container_name: str):
        """Get detailed status, uptime, ports, and mounts for a container."""
        # SYNO.Docker.Container/get accepts the clean name (no hash prefix).
        clean_name = _strip_hash_prefix(container_name)
        try:
            data = await client.request(
                "SYNO.Docker.Container",
                "get",
                params={"name": clean_name},
            )
        except Exception as e:
            return f"Error getting container '{container_name}': {e}"

        if not data:
            return f"Container '{container_name}' not found."

        return _format_container_detail(clean_name, data)

    @mcp.tool()
    async def get_container_logs(
        container_name: str,
        tail: int = 100,
        keyword: str | None = None,
    ):
        """Get recent log output from a container, with optional keyword filter."""
        resolved_name = await _resolve_container_name(client, container_name)
        params: dict[str, Any] = {
            "name": resolved_name,
            "limit": tail,
            "offset": 0,
            "sort_dir": "DESC",
        }
        if keyword:
            params["keyword"] = keyword

        try:
            data = await client.request(
                "SYNO.Docker.Container.Log",
                "get",
                params=params,
            )
        except Exception as e:
            return f"Error getting logs for '{container_name}': {e}"

        logs: list[dict[str, Any]] = data.get("logs", [])
        if not logs:
            return f"No logs found for container '{container_name}'."

        total = data.get("total", len(logs))
        display_name = _strip_hash_prefix(container_name)
        header = f"Logs for {display_name} (showing {len(logs)} of {total}):\n"

        # Logs are returned in DESC order, reverse for chronological display
        lines = []
        for entry in reversed(logs):
            timestamp = entry.get("created", "")
            stream = entry.get("stream", "")
            text = entry.get("text", "")
            stream_tag = f"[{stream}] " if stream else ""
            lines.append(f"{timestamp}  {stream_tag}{text}")

        return header + "\n".join(lines)

    @mcp.tool()
    async def container_stats(container_name: str):
        """Get live CPU, memory, network, and block I/O stats for a container."""
        try:
            data = await client.request("SYNO.Docker.Container", "stats")
        except Exception as e:
            return f"Error fetching container stats: {e}"

        if not data:
            return "No stats data returned."

        # Response is a dict keyed by container ID hash; each entry has "name"
        # with a leading slash (e.g. "/jenkins") and may have a hash prefix.
        clean_query = _strip_hash_prefix(container_name)
        target: dict[str, Any] | None = None
        for entry in data.values():
            entry_name = _strip_hash_prefix(entry.get("name", ""))
            if entry_name == clean_query:
                target = entry
                break

        if target is None:
            available = ", ".join(_strip_hash_prefix(v.get("name", "?")) for v in data.values())
            return f"Container '{container_name}' not found in stats. Available: {available}"

        # ── CPU % ────────────────────────────────────────────────────────────
        cpu_stats = target.get("cpu_stats", {})
        precpu_stats = target.get("precpu_stats", {})
        cpu_usage = cpu_stats.get("cpu_usage", {})
        precpu_usage = precpu_stats.get("cpu_usage", {})

        cpu_delta = cpu_usage.get("total_usage", 0) - precpu_usage.get("total_usage", 0)
        system_delta = cpu_stats.get("system_cpu_usage", 0) - precpu_stats.get(
            "system_cpu_usage", 0
        )
        online_cpus = cpu_stats.get("online_cpus") or len(cpu_usage.get("percpu_usage") or [1])

        if system_delta > 0 and cpu_delta >= 0:
            cpu_pct = (cpu_delta / system_delta) * online_cpus * 100.0
        else:
            cpu_pct = 0.0

        # ── Memory ───────────────────────────────────────────────────────────
        mem_stats = target.get("memory_stats", {})
        mem_usage = mem_stats.get("usage", 0)
        mem_limit = mem_stats.get("limit", 0)

        # ── Network I/O ──────────────────────────────────────────────────────
        net_rx = 0
        net_tx = 0
        for iface in (target.get("networks") or {}).values():
            net_rx += iface.get("rx_bytes", 0)
            net_tx += iface.get("tx_bytes", 0)

        # ── Block I/O ────────────────────────────────────────────────────────
        blk_read = 0
        blk_write = 0
        for entry_io in target.get("blkio_stats", {}).get("io_service_bytes_recursive") or []:
            op = entry_io.get("op", "").lower()
            val = entry_io.get("value", 0)
            if op == "read":
                blk_read += val
            elif op == "write":
                blk_write += val

        # ── Format ───────────────────────────────────────────────────────────
        from mcp_synology_container.modules.images import _human_size  # reuse helper

        mem_limit_str = f" / {_human_size(mem_limit)}" if mem_limit else ""
        lines = [
            f"Stats for {container_name}:",
            f"  CPU:       {cpu_pct:.2f}%  ({online_cpus} CPUs)",
            f"  Memory:    {_human_size(mem_usage)}{mem_limit_str}",
            f"  Net I/O:   rx {_human_size(net_rx)}  /  tx {_human_size(net_tx)}",
            f"  Block I/O: read {_human_size(blk_read)}  /  write {_human_size(blk_write)}",
        ]
        return "\n".join(lines)

    @mcp.tool()
    async def exec_in_container(
        container_name: str,
        command: str,
        confirmed: bool = False,
    ):
        """Execute a shell command inside a running container. Requires confirmed=True."""
        if not confirmed:
            return (
                f"About to run in container '{container_name}':\n"
                f"  $ {command}\n\n"
                f"Call this tool again with confirmed=True to proceed."
            )

        resolved_name = await _resolve_container_name(client, container_name)
        try:
            data = await client.request(
                "SYNO.Docker.Container",
                "exec",
                params={
                    "name": resolved_name,
                    "command": command,
                },
            )
        except Exception as e:
            return f"Error executing command in '{container_name}': {e}"

        output = data.get("output", "")
        exit_code = data.get("exit_code", 0)

        result_lines = [f"Command executed in '{container_name}':"]
        result_lines.append(f"  Exit code: {exit_code}")
        if output:
            result_lines.append("  Output:")
            result_lines.append(output)

        return "\n".join(result_lines)

    @mcp.tool()
    async def delete_container(container_name: str, confirmed: bool = False):
        """Delete a stopped container. Requires confirmed=True."""
        if not confirmed:
            return (
                f"Preview: would delete container '{container_name}'.\n"
                f"Call this tool again with confirmed=True to proceed."
            )

        resolved_name = await _resolve_container_name(client, container_name)
        display_name = _strip_hash_prefix(resolved_name)

        try:
            data = await client.request(
                "SYNO.Docker.Container",
                "get",
                params={"name": resolved_name},
            )
        except Exception as e:
            return f"Error inspecting container '{container_name}': {e}"

        if not data:
            return f"Container '{container_name}' not found."

        details = data.get("details", {}) or {}
        state = details.get("State", {}) or {}
        running = state.get("Running", False)

        if running:
            return (
                f"Cannot delete '{display_name}': container is still running.\n"
                f"Stop the container first with stop_project or stop_container."
            )

        try:
            await client.request(
                "SYNO.Docker.Container",
                "delete",
                params={
                    "name": json.dumps(resolved_name),
                    "force": "false",
                    "preserve_profile": "false",
                },
            )
            return f"Deleted container '{display_name}'."
        except Exception as e:
            return f"Error deleting '{display_name}': {e}"


def _container_in_project(container: dict[str, Any], project_name: str) -> bool:
    """Check if a container belongs to a project based on its labels."""
    labels = container.get("labels", {}) or {}
    if isinstance(labels, dict):
        return labels.get("com.docker.compose.project") == project_name
    return False


def _format_container_detail(name: str, data: dict[str, Any]) -> str:
    """Format container inspect data as human-readable text.

    SYNO.Docker.Container/get returns two top-level keys:
      - "details": Docker Engine inspect format (State, NetworkSettings, Mounts, …)
      - "profile":  DSM format (image, port_bindings, …)
    """
    details: dict[str, Any] = data.get("details", {}) or {}
    profile: dict[str, Any] = data.get("profile", {}) or {}

    state: dict[str, Any] = details.get("State", {}) or {}
    status_str = state.get("Status", "?")
    running = state.get("Running", False)
    image_str = profile.get("image", "?")

    lines = [
        f"Container: {name}",
        f"  Status:    {status_str}",
        f"  Running:   {running}",
        f"  Image:     {image_str}",
    ]

    if state.get("StartedAt"):
        lines.append(f"  Started:   {state['StartedAt']}")
    if state.get("FinishedAt") and not running:
        lines.append(f"  Finished:  {state['FinishedAt']}")
        lines.append(f"  Exit code: {state.get('ExitCode', '?')}")

    # IP addresses from all attached networks
    networks: dict[str, Any] = (details.get("NetworkSettings", {}) or {}).get("Networks", {}) or {}
    for net_name, net in networks.items():
        ip = (net or {}).get("IPAddress", "")
        if ip:
            lines.append(f"  IP ({net_name}): {ip}")

    # Port bindings from DSM profile
    port_bindings: list[dict[str, Any]] = profile.get("port_bindings", []) or []
    if port_bindings:
        lines.append("  Ports:")
        for pb in port_bindings:
            host = pb.get("host_port", "?")
            ctr = pb.get("container_port", "?")
            proto = pb.get("type", "tcp")
            lines.append(f"    {host} → {ctr}/{proto}")

    # Mounts from Docker Engine inspect
    mounts: list[dict[str, Any]] = details.get("Mounts", []) or []
    if mounts:
        lines.append("  Mounts:")
        for m in mounts:
            src = m.get("Source", "?")
            dst = m.get("Destination", "?")
            mtype = m.get("Type", "")
            rw = "" if m.get("RW", True) else " [ro]"
            type_tag = f" ({mtype})" if mtype else ""
            lines.append(f"    {src} → {dst}{type_tag}{rw}")

    return "\n".join(lines)