package tools

import (
	"context"
	"fmt"
	"net/url"
	"strconv"

	"github.com/modelcontextprotocol/go-sdk/mcp"
)

// lxc.go — LXC-контейнеры: чтение (list/describe/config) + lifecycle
// (start/stop/reboot/shutdown), clone, delete, config_update, resize.
// Всё по аналогии с QEMU, но через /lxc. Мутации = gate + confirm + probe.

const vmTypeLXC = "lxc"

func registerLXCTools(s *mcp.Server) {
	// --- read ---
	s.AddTool(&mcp.Tool{
		Name:        "containers_list",
		Description: "List LXC containers across the cluster. Read-only.",
		InputSchema: schema(map[string]any{
			"host": strProps("Cluster alias (default: primary)", false),
		}, nil),
	}, containersListHandler)

	s.AddTool(&mcp.Tool{
		Name:        "container_describe",
		Description: "Describe one LXC container: status + config. Read-only.",
		InputSchema: schema(map[string]any{
			"node": strProps("Node name", true),
			"vmid": strProps("CT ID", true),
			"host": strProps("Cluster alias (default: primary)", false),
		}, []string{"node", "vmid"}),
	}, containerDescribeHandler)

	s.AddTool(&mcp.Tool{
		Name:        "container_config",
		Description: "Get the raw LXC config of a container. Read-only.",
		InputSchema: schema(map[string]any{
			"node": strProps("Node name", true),
			"vmid": strProps("CT ID", true),
			"host": strProps("Cluster alias (default: primary)", false),
		}, []string{"node", "vmid"}),
	}, containerConfigHandler)

	// --- lifecycle ---
	registerPatternTool(s, &mcp.Tool{
		Name:        "container_start",
		Description: "Start an LXC container. Requires write permission.",
		InputSchema: containerActionSchema(false),
	}, vmPatterns, containerStartHandler)
	registerPatternTool(s, &mcp.Tool{
		Name:        "container_stop",
		Description: "Stop an LXC container. Requires confirm + write permission.",
		InputSchema: containerActionSchema(true),
	}, vmPatterns, containerStopHandler)
	registerPatternTool(s, &mcp.Tool{
		Name:        "container_reboot",
		Description: "Reboot an LXC container. Requires confirm + write permission.",
		InputSchema: containerActionSchema(true),
	}, vmPatterns, containerRebootHandler)
	registerPatternTool(s, &mcp.Tool{
		Name:        "container_shutdown",
		Description: "Gracefully shut down an LXC container. Requires confirm + write permission.",
		InputSchema: containerActionSchema(true),
	}, vmPatterns, containerShutdownHandler)

	// --- clone / delete / config / resize ---
	registerPatternTool(s, &mcp.Tool{
		Name:        "container_clone",
		Description: "Clone an LXC container/template into a new CT ID. Requires confirm + write permission.",
		InputSchema: schema(map[string]any{
			"node":    strProps("Node name", true),
			"vmid":    strProps("Source CT ID", true),
			"newid":   intProps("New CT ID (0 = next free)", false),
			"name":    strProps("Name for the clone", false),
			"confirm": strProps("Set to \"true\" to confirm", true, "true"),
		}, []string{"node", "vmid", "confirm"}),
	}, vmPatterns, containerCloneHandler)

	registerPatternTool(s, &mcp.Tool{
		Name:        "container_delete",
		Description: "Permanently delete an LXC container. Requires confirm + write permission.",
		InputSchema: schema(map[string]any{
			"node":    strProps("Node name", true),
			"vmid":    strProps("CT ID", true),
			"confirm": strProps("Set to \"true\" to confirm permanent deletion", true, "true"),
		}, []string{"node", "vmid", "confirm"}),
	}, vmPatterns, containerDeleteHandler)

	registerPatternTool(s, &mcp.Tool{
		Name:        "container_config_update",
		Description: "Update safe LXC config fields (hostname, memory, swap, cores, unprivileged). Denied keys rejected. Requires confirm + write permission.",
		InputSchema: schema(map[string]any{
			"node":    strProps("Node name", true),
			"vmid":    strProps("CT ID", true),
			"updates": objectProps("Object of key->value config fields", true),
			"confirm": strProps("Set to \"true\" to confirm", true, "true"),
		}, []string{"node", "vmid", "updates", "confirm"}),
	}, vmPatterns, containerConfigUpdateHandler)

	registerPatternTool(s, &mcp.Tool{
		Name:        "container_resize",
		Description: "Resize a rootfs/mountpoint of an LXC container. Requires confirm + write permission.",
		InputSchema: schema(map[string]any{
			"node":    strProps("Node name", true),
			"vmid":    strProps("CT ID", true),
			"disk":    strProps("Disk to resize (e.g. rootfs)", true),
			"size":    strProps("Size change, e.g. +5G", true),
			"confirm": strProps("Set to \"true\" to confirm", true, "true"),
		}, []string{"node", "vmid", "disk", "size", "confirm"}),
	}, vmPatterns, containerResizeHandler)
}

// containerActionSchema — схема для lifecycle LXC (с/без confirm).
func containerActionSchema(withConfirm bool) map[string]any {
	props := map[string]any{
		"node": strProps("Node name", true),
		"vmid": strProps("CT ID", true),
	}
	req := []string{"node", "vmid"}
	if withConfirm {
		props["confirm"] = strProps("Set to \"true\" to confirm", true, "true")
		req = append(req, "confirm")
	}
	return schema(props, req)
}

// --- read ---

func containersListHandler(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	t, err := tenantFor(ctx, req)
	if err != nil {
		return errorResult(err.Error()), nil
	}
	host, err := resolveHost(t, requestArgs(req))
	if err != nil {
		return errorResult(err.Error()), nil
	}
	cctx, cancel := timeout(ctx, t)
	defer cancel()
	data, err := t.GuestResources(cctx, host, vmTypeLXC)
	if err != nil {
		return errorResult(err.Error()), nil
	}
	return textResult(pretty(data)), nil
}

func containerDescribeHandler(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	t, err := tenantFor(ctx, req)
	if err != nil {
		return errorResult(err.Error()), nil
	}
	args := requestArgs(req)
	node, vmid, host, r := resolveVMArgs(t, args)
	if r != nil {
		return r, nil
	}
	cctx, cancel := timeout(ctx, t)
	defer cancel()
	status, err := t.ContainerStatus(cctx, host, node, vmid)
	if err != nil {
		return errorResult(err.Error()), nil
	}
	cfg, err := t.ContainerConfig(cctx, host, node, vmid)
	if err != nil {
		return errorResult(err.Error()), nil
	}
	return textResult("=== Status ===\n" + pretty(status) + "\n\n=== Config ===\n" + pretty(cfg)), nil
}

func containerConfigHandler(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	t, err := tenantFor(ctx, req)
	if err != nil {
		return errorResult(err.Error()), nil
	}
	args := requestArgs(req)
	node, vmid, host, r := resolveVMArgs(t, args)
	if r != nil {
		return r, nil
	}
	cctx, cancel := timeout(ctx, t)
	defer cancel()
	data, err := t.ContainerConfig(cctx, host, node, vmid)
	if err != nil {
		return errorResult(err.Error()), nil
	}
	return textResult(pretty(data)), nil
}

// --- lifecycle ---

func containerStartHandler(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	return containerActionHandler(ctx, req, "start", false)
}
func containerStopHandler(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	return containerActionHandler(ctx, req, "stop", true)
}
func containerRebootHandler(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	return containerActionHandler(ctx, req, "reboot", true)
}
func containerShutdownHandler(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	return containerActionHandler(ctx, req, "shutdown", true)
}

func containerActionHandler(ctx context.Context, req *mcp.CallToolRequest, action string, needConfirm bool) (*mcp.CallToolResult, error) {
	t, err := tenantFor(ctx, req)
	if err != nil {
		return errorResult(err.Error()), nil
	}
	args := requestArgs(req)
	node, vmid, host, r := resolveVMArgs(t, args)
	if r != nil {
		return r, nil
	}
	if needConfirm {
		if err := confirm(args, "container_"+action); err != nil {
			return errorResult(err.Error()), nil
		}
	}
	if err := gateVMWrite(t, host, vmid); err != nil {
		return errorResult(err.Error()), nil
	}
	upid, err := t.ContainerAction(ctx, host, node, vmid, action)
	if err != nil {
		return errorResult(err.Error()), nil
	}
	return textResult(upidMsg("container_"+action, fmt.Sprintf("%s/%d", node, vmid), upid)), nil
}

func containerCloneHandler(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	t, err := tenantFor(ctx, req)
	if err != nil {
		return errorResult(err.Error()), nil
	}
	args := requestArgs(req)
	node, src, host, r := resolveVMArgs(t, args)
	if r != nil {
		return r, nil
	}
	if err := confirm(args, "container_clone"); err != nil {
		return errorResult(err.Error()), nil
	}
	if err := gateVMWrite(t, host, src); err != nil {
		return errorResult(err.Error()), nil
	}
	newID := getInt(args, "newid", 0)
	if newID == 0 {
		data, err := t.NextID(ctx, host)
		if err != nil {
			return errorResult(err.Error()), nil
		}
		newID = intFromData(data)
	}
	form := url.Values{"newid": {strconv.Itoa(newID)}}
	if name := getString(args, "name", ""); name != "" {
		form.Set("name", name)
	}
	upid, err := t.ContainerClone(ctx, host, node, src, newID, form)
	if err != nil {
		return errorResult(err.Error()), nil
	}
	return textResult(upidMsg("container_clone", fmt.Sprintf("%d -> %d", src, newID), upid)), nil
}

func containerDeleteHandler(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	t, err := tenantFor(ctx, req)
	if err != nil {
		return errorResult(err.Error()), nil
	}
	args := requestArgs(req)
	node, vmid, host, r := resolveVMArgs(t, args)
	if r != nil {
		return r, nil
	}
	if err := confirm(args, "container_delete"); err != nil {
		return errorResult(err.Error()), nil
	}
	if err := gateVMWrite(t, host, vmid); err != nil {
		return errorResult(err.Error()), nil
	}
	upid, err := t.ContainerDelete(ctx, host, node, vmid)
	if err != nil {
		return errorResult(err.Error()), nil
	}
	return textResult(upidMsg("container_delete", fmt.Sprintf("%s/%d", node, vmid), upid)), nil
}

func containerConfigUpdateHandler(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	t, err := tenantFor(ctx, req)
	if err != nil {
		return errorResult(err.Error()), nil
	}
	args := requestArgs(req)
	node, vmid, host, r := resolveVMArgs(t, args)
	if r != nil {
		return r, nil
	}
	if err := confirm(args, "container_config_update"); err != nil {
		return errorResult(err.Error()), nil
	}
	if err := gateVMWrite(t, host, vmid); err != nil {
		return errorResult(err.Error()), nil
	}
	updates := getObject(args, "updates")
	if len(updates) == 0 {
		return errorResult("'updates' must be a non-empty object"), nil
	}
	form := make(url.Values, len(updates))
	for k, v := range updates {
		if t.Config().DenyConfigKey(k) {
			return errorResult(fmt.Sprintf("field %q is denied by policy", k)), nil
		}
		form.Set(k, fmt.Sprint(v))
	}
	upid, err := t.ConfigPost(ctx, host, node, vmTypeLXC, vmid, form)
	if err != nil {
		return errorResult(err.Error()), nil
	}
	return textResult(upidMsg("container_config_update", fmt.Sprintf("%s/%d", node, vmid), upid)), nil
}

func containerResizeHandler(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
	t, err := tenantFor(ctx, req)
	if err != nil {
		return errorResult(err.Error()), nil
	}
	args := requestArgs(req)
	node, vmid, host, r := resolveVMArgs(t, args)
	if r != nil {
		return r, nil
	}
	if err := confirm(args, "container_resize"); err != nil {
		return errorResult(err.Error()), nil
	}
	if err := gateVMWrite(t, host, vmid); err != nil {
		return errorResult(err.Error()), nil
	}
	disk, err := requireName(args, "disk")
	if err != nil {
		return errorResult(err.Error()), nil
	}
	size := getString(args, "size", "")
	if size == "" {
		return errorResult("'size' is required (e.g. +5G)"), nil
	}
	upid, err := t.ResizeDisk(ctx, host, node, vmTypeLXC, vmid, url.Values{"disk": {disk}, "size": {size}})
	if err != nil {
		return errorResult(err.Error()), nil
	}
	return textResult(upidMsg("container_resize", fmt.Sprintf("%s/%d %s", node, vmid, disk), upid)), nil
}