// Package server builds the MCP server and registers the WikiJS tools.
package server

import (
	"log/slog"

	"gogs.netdome.biz/paul/go-wikijs-mcp/internal/wikijs"

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

const instructions = `This server exposes a WikiJS knowledge base.
Use search_pages to find pages by full-text query, get_page_by_id or
get_page_by_path to read a page, and get_all_pages to browse the wiki.
Page results include absolute URLs that can be shared with the user.
Assets are managed store-wide, not per page: list_asset_folders and
list_assets browse the central asset store, and when the write tools are
enabled upload_asset adds files and create_asset_folder adds folders.
Reference uploaded assets from pages with the returned markdown snippet.`

// Options configures the MCP server.
type Options struct {
	// Version is reported to MCP clients.
	Version string
	// EnableEdit exposes the create_page and edit_page tools.
	EnableEdit bool
	// Logger receives MCP protocol logs. It must write to stderr when the
	// stdio transport is used.
	Logger *slog.Logger
}

// New creates an MCP server with all WikiJS tools registered.
func New(client *wikijs.Client, opts Options) *mcp.Server {
	logger := opts.Logger
	if logger == nil {
		logger = slog.New(slog.DiscardHandler)
	}

	s := mcp.NewServer(&mcp.Implementation{
		Name:        "wikijs-mcp-server",
		Title:       "WikiJS MCP Server",
		Version:     opts.Version,
		Description: "Search, read, and optionally edit pages in a WikiJS instance.",
	}, &mcp.ServerOptions{
		Instructions: instructions,
		Logger:       logger,
	})

	h := &handlers{wiki: client}

	readOnly := &mcp.ToolAnnotations{ReadOnlyHint: true}
	mcp.AddTool(s, &mcp.Tool{
		Name:        "search_pages",
		Title:       "Search pages",
		Description: "Search for pages in WikiJS by query string.",
		Annotations: readOnly,
	}, h.searchPages)
	mcp.AddTool(s, &mcp.Tool{
		Name:        "get_page_by_id",
		Title:       "Get page by ID",
		Description: "Get a WikiJS page by its numeric ID.",
		Annotations: readOnly,
	}, h.pageByID)
	mcp.AddTool(s, &mcp.Tool{
		Name:        "get_page_by_path",
		Title:       "Get page by path",
		Description: "Get a WikiJS page by its path and locale.",
		Annotations: readOnly,
	}, h.pageByPath)
	mcp.AddTool(s, &mcp.Tool{
		Name:        "get_all_pages",
		Title:       "List pages",
		Description: "List pages in WikiJS, optionally filtered by limit, locale, and tags.",
		Annotations: readOnly,
	}, h.listPages)
	mcp.AddTool(s, &mcp.Tool{
		Name:        "list_asset_folders",
		Title:       "List asset folders",
		Description: "List the child folders of a WikiJS asset folder (root by default).",
		Annotations: readOnly,
	}, h.listAssetFolders)
	mcp.AddTool(s, &mcp.Tool{
		Name:        "list_assets",
		Title:       "List assets",
		Description: "List the files uploaded to a WikiJS asset folder (root by default), optionally filtered by kind.",
		Annotations: readOnly,
	}, h.listAssets)

	if opts.EnableEdit {
		notDestructive := false
		mcp.AddTool(s, &mcp.Tool{
			Name:        "create_page",
			Title:       "Create page",
			Description: "Create a new WikiJS page.",
			Annotations: &mcp.ToolAnnotations{DestructiveHint: &notDestructive},
		}, h.createPage)
		// edit_page advertises IdempotentHint: editing the same page twice
		// with the same content converges to the same state, unlike
		// create_page and upload_asset, which would duplicate work.
		mcp.AddTool(s, &mcp.Tool{
			Name:        "edit_page",
			Title:       "Edit page",
			Description: "Edit an existing WikiJS page by its numeric ID.",
			Annotations: &mcp.ToolAnnotations{IdempotentHint: true},
		}, h.editPage)
		mcp.AddTool(s, &mcp.Tool{
			Name:        "upload_asset",
			Title:       "Upload asset",
			Description: "Upload a file to a WikiJS asset folder so it can be referenced from pages.",
			Annotations: &mcp.ToolAnnotations{DestructiveHint: &notDestructive},
		}, h.uploadAsset)
		mcp.AddTool(s, &mcp.Tool{
			Name:        "create_asset_folder",
			Title:       "Create asset folder",
			Description: "Create a new WikiJS asset folder.",
			Annotations: &mcp.ToolAnnotations{DestructiveHint: &notDestructive},
		}, h.createAssetFolder)
	}

	return s
}