import type { AxiosInstance } from "axios";
import {
  applyBulkMenuOperations,
  applyMenuAddNode,
  applyMenuMoveNode,
  applyMenuRemoveNode,
  applyMenuUpdateTranslation,
  collectMenuLinksFromTree,
  createMenuSnapshot,
  describeMenuNode,
  normalizeMenuPayloadForWrite,
  restoreMenuSnapshot,
  validateMenuItems,
  validateMenuNodeData,
  validateMenuTranslations,
  validateMenuTreeSnapshot,
  cloneMenuValue,
  isPlainObject,
} from "./menu-tools";

export const MENU_TOOL_DEFINITIONS = [
  {
    name: "get_menu",
    description: "Fetch a specific menu and its items (including translations)",
    inputSchema: {
      type: "object",
      properties: {
        name: { type: "string", description: "Name of the menu (e.g. main, footer-explore)" }
      },
      required: ["name"]
    }
  },
  {
    name: "upsert_menu",
    description: "Update or create a complete menu by replacing its items. Optional payload/isActive support covers tree-based menus and menu state. Uses proper diff & sync for translations.",
    inputSchema: {
      type: "object",
      properties: {
        name: { type: "string", description: "Name of the menu (e.g. main, footer-explore)" },
        dryRun: { type: "boolean", description: "Preview the mutation without saving it" },
        payload: {
          oneOf: [{ type: "object" }, { type: "array" }],
          description: "Optional menu payload for tree-based menus such as main"
        },
        isActive: { type: "boolean", description: "Optional active state for the menu" },
        items: {
          type: "array",
          description: "Array of menu items",
          items: {
            type: "object",
            properties: {
              id: { type: "number", description: "ID of existing item (optional)" },
              label: { type: "string", description: "Label of the menu item" },
              url: { type: "string", description: "URL of the menu item" },
              order: { type: "number", description: "Order sequence" },
              translations: {
                type: "array",
                description: "Optional array of translations",
                items: {
                  type: "object",
                  properties: {
                    langCode: { type: "string" },
                    label: { type: "string" }
                  }
                }
              }
            },
            required: ["label", "url", "order"]
          }
        }
      },
      required: ["name"]
    }
  },
  {
    name: "audit_missing_pages",
    description: "Audit all menus and find links that do not have a corresponding dynamic page or hardcoded route",
    inputSchema: { type: "object", properties: {} }
  },
  {
    name: "get_mega_menu_tree",
    description: "Read Mega Menu (main) payload, auto-generate nodeId for all nodes if missing, and return the tree.",
    inputSchema: { type: "object", properties: {} }
  },
  {
    name: "capture_menu_snapshot",
    description: "Capture the current state of a menu so it can be restored later.",
    inputSchema: {
      type: "object",
      properties: {
        name: { type: "string", description: "Name of the menu to snapshot (e.g. main, footer-explore)" }
      },
      required: ["name"]
    }
  },
  {
    name: "restore_menu_snapshot",
    description: "Restore a previously captured menu snapshot by snapshotId.",
    inputSchema: {
      type: "object",
      properties: {
        snapshotId: { type: "string", description: "Snapshot identifier returned by capture_menu_snapshot" },
        dryRun: { type: "boolean", description: "Preview the mutation without saving it" }
      },
      required: ["snapshotId"]
    }
  },
  {
    name: "bulk_menu_operations",
    description: "Apply multiple menu tree operations in a single transaction. Supports add_node, update_translation, move_node, and remove_node.",
    inputSchema: {
      type: "object",
      properties: {
        name: { type: "string", description: "Name of the menu to modify (e.g. main, footer-explore)" },
        dryRun: { type: "boolean", description: "Preview the mutation without saving it" },
        operations: {
          type: "array",
          description: "Array of menu operations to apply in order",
          items: {
            type: "object",
            properties: {
              type: { type: "string", enum: ["add_node", "update_translation", "move_node", "remove_node"] },
              parentId: { type: "string", description: "Parent node ID for add_node" },
              nodeId: { type: "string", description: "Target node ID for update/move/remove" },
              newParentId: { type: "string", description: "New parent node ID for move_node" },
              orderIndex: { type: "number", description: "Insertion index for move_node" },
              translations: { type: "object", description: "Translation map for update_translation" },
              nodeData: { type: "object", description: "Node data for add_node" }
            },
            required: ["type"]
          }
        }
      },
      required: ["name", "operations"]
    }
  },
  {
    name: "add_menu_node",
    description: "Add a new node to the Mega Menu tree. CRITICAL RULE: Mega Menu structure is Root -> Column -> Link. Do NOT add a Link directly under Root. If you want to add a Link, you MUST check if a Column exists first. If no Column exists, create a Column node first, then add the Link under that Column.",
    inputSchema: {
      type: "object",
      properties: {
        parentId: { type: "string", description: "UUID of parent node, or 'root'" },
        dryRun: { type: "boolean", description: "Preview the mutation without saving it" },
        nodeData: { type: "object", description: "Node data including label, url, translations, etc." }
      },
      required: ["nodeData"]
    }
  },
  {
    name: "update_menu_translation",
    description: "Update 6-language translations for a specific node in the Mega Menu",
    inputSchema: {
      type: "object",
      properties: {
        nodeId: { type: "string", description: "UUID of the node" },
        dryRun: { type: "boolean", description: "Preview the mutation without saving it" },
        translations: {
          type: "object",
          description: "Object containing language codes as keys (th, en, etc.) and translated strings as values."
        }
      },
      required: ["nodeId", "translations"]
    }
  },
  {
    name: "move_menu_node",
    description: "Move a node to a new parent or change its order",
    inputSchema: {
      type: "object",
      properties: {
        nodeId: { type: "string" },
        newParentId: { type: "string", description: "UUID of new parent, or 'root'" },
        dryRun: { type: "boolean", description: "Preview the mutation without saving it" },
        orderIndex: { type: "number", description: "New index in the parent's children array" }
      },
      required: ["nodeId"]
    }
  },
  {
    name: "remove_menu_node",
    description: "Remove a node and all its children from the Mega Menu",
    inputSchema: {
      type: "object",
      properties: {
        nodeId: { type: "string" },
        dryRun: { type: "boolean", description: "Preview the mutation without saving it" }
      },
      required: ["nodeId"]
    }
  }
] as const;

export const MENU_TOOL_NAMES = new Set(MENU_TOOL_DEFINITIONS.map((tool) => tool.name));

export async function handleMenuTool(api: AxiosInstance, name: string, params: any) {
  if (!MENU_TOOL_NAMES.has(name)) return null;

  switch (name) {
    case "get_menu": {
      const res = await api.get(`/menus/${params.name}`);
      return { content: [{ type: "text", text: JSON.stringify(res.data, null, 2) }] };
    }
    case "upsert_menu": {
      const dryRun = !!params.dryRun;
      const items = Array.isArray(params.items) ? params.items : [];
      const body: any = { items };
      const itemCheck = validateMenuItems(items);
      if (itemCheck.issues.length > 0) {
        throw new Error(`Invalid menu items: ${itemCheck.issues.join("; ")}`);
      }
      if (params.payload !== undefined) body.payload = params.payload;
      if (params.isActive !== undefined) body.isActive = params.isActive;
      if (params.payload !== undefined && !isPlainObject(params.payload) && !Array.isArray(params.payload)) {
        throw new Error("Invalid menu payload: payload must be an object or array");
      }

      if (dryRun) {
        return {
          content: [
            {
              type: "text",
              text: JSON.stringify(
                {
                  success: true,
                  dryRun: true,
                  operation: "upsert_menu",
                  menuName: params.name,
                  preview: {
                    name: params.name,
                    items: cloneMenuValue(items),
                    payload: params.payload !== undefined ? cloneMenuValue(params.payload) : undefined,
                    isActive: params.isActive
                  },
                  warnings: itemCheck.warnings
                },
                null,
                2
              )
            }
          ]
        };
      }

      const res = await api.put(`/menus/${params.name}`, body);
      return { content: [{ type: "text", text: JSON.stringify(res.data, null, 2) }] };
    }
    case "audit_missing_pages": {
      const menusRes = await api.get("/menus");
      const menus = menusRes.data || [];
      const pagesRes = await api.get("/pages");
      const pages = pagesRes.data || [];
      const createdSlugs = pages.map((p: any) => `/${p.slug}`);
      const hardcodedRoutes = ["/", "/shop", "/login", "/cart", "/checkout", "/account", "/search", "/contact"];

      const missingLinks: any[] = [];
      const duplicates: any[] = [];
      const treeIssues: any[] = [];

      menus.forEach((menu: any) => {
        const seenUrls = new Set<string>();
        const urls = [
          ...(Array.isArray(menu.items)
            ? menu.items.filter((item: any) => item?.url).map((item: any) => ({ url: item.url, label: item.label, source: "items" as const }))
            : []),
          ...(Array.isArray(menu.payload) ? collectMenuLinksFromTree(menu.payload) : []),
        ];
        const uniqueUrls = [...new Map(urls.map((entry) => [entry.url, entry])).values()];

        uniqueUrls.forEach(({ url, label, source }) => {
          if (seenUrls.has(url)) {
            duplicates.push({ menuName: menu.name, url, label: label || url, source });
            return;
          }
          seenUrls.add(url);
          if (url.startsWith("http") || url.startsWith("mailto:") || url.startsWith("tel:")) return;
          if (hardcodedRoutes.includes(url)) return;
          if (url.startsWith("/collections/")) return;
          if (!createdSlugs.includes(url)) {
            missingLinks.push({
              menuName: menu.name,
              label: label || url,
              url,
              suggestedSlug: url.startsWith("/") ? url.substring(1) : url,
              source,
            });
          }
        });

        if (Array.isArray(menu.payload)) {
          const treeCheck = validateMenuTreeSnapshot(menu.payload);
          treeIssues.push({ menuName: menu.name, issues: treeCheck.issues, warnings: treeCheck.warnings });
        }
      });

      return {
        content: [
          {
            type: "text",
            text: JSON.stringify({ missingPages: missingLinks, duplicates, treeIssues }, null, 2)
          }
        ]
      };
    }
    case "get_mega_menu_tree": {
      const res = await api.get(`/menus/main`);
      const menu = res.data;
      const normalized = normalizeMenuPayloadForWrite(menu.payload);
      if (normalized.modified) {
        await api.put(`/menus/main`, { payload: normalized.payload, items: menu.items || [] });
      }
      return { content: [{ type: "text", text: JSON.stringify(normalized.payload, null, 2) }] };
    }
    case "capture_menu_snapshot": {
      const res = await api.get(`/menus/${params.name}`);
      const snapshot = createMenuSnapshot(res.data);
      return {
        content: [
          {
            type: "text",
            text: JSON.stringify(
              {
                success: true,
                operation: "capture_menu_snapshot",
                snapshotId: snapshot.snapshotId,
                name: snapshot.name,
                createdAt: snapshot.createdAt,
                itemCount: snapshot.items.length,
                hasTreePayload: snapshot.payload.length > 0
              },
              null,
              2
            )
          }
        ]
      };
    }
    case "restore_menu_snapshot": {
      const dryRun = !!params.dryRun;
      const snapshot = restoreMenuSnapshot(params.snapshotId);
      const preview = { name: snapshot.name, payload: snapshot.payload, items: snapshot.items, isActive: snapshot.isActive };
      if (dryRun) {
        return {
          content: [
            {
              type: "text",
              text: JSON.stringify({ success: true, dryRun: true, operation: "restore_menu_snapshot", snapshotId: params.snapshotId, preview }, null, 2)
            }
          ]
        };
      }

      const res = await api.put(`/menus/${snapshot.name}`, {
        payload: snapshot.payload,
        items: snapshot.items,
        isActive: snapshot.isActive
      });
      return { content: [{ type: "text", text: JSON.stringify({ success: true, snapshotId: params.snapshotId, menu: res.data }, null, 2) }] };
    }
    case "bulk_menu_operations": {
      const dryRun = !!params.dryRun;
      if (!Array.isArray(params.operations) || params.operations.length === 0) {
        throw new Error("operations must be a non-empty array");
      }

      const res = await api.get(`/menus/${params.name}`);
      const menu = res.data;
      const result = applyBulkMenuOperations(Array.isArray(menu.payload) ? menu.payload : [], params.operations);

      if (dryRun) {
        return {
          content: [
            {
              type: "text",
              text: JSON.stringify(
                { success: true, dryRun: true, operation: "bulk_menu_operations", menuName: params.name, warnings: result.warnings, applied: result.applied, preview: { payload: result.payload } },
                null,
                2
              )
            }
          ]
        };
      }

      const normalized = normalizeMenuPayloadForWrite(result.payload);
      const writeBody: any = { payload: normalized.payload, items: menu.items || [] };
      if (menu.isActive !== undefined) {
        writeBody.isActive = menu.isActive;
      }
      const writeRes = await api.put(`/menus/${params.name}`, writeBody);
      return {
        content: [
          {
            type: "text",
            text: JSON.stringify({ success: true, operation: "bulk_menu_operations", menuName: params.name, warnings: result.warnings, applied: result.applied, menu: writeRes.data }, null, 2)
          }
        ]
      };
    }
    case "add_menu_node": {
      const { parentId, nodeData } = params;
      const dryRun = !!params.dryRun;
      const res = await api.get(`/menus/main`);
      const menu = res.data;
      const validation = validateMenuNodeData(nodeData, parentId);
      if (validation.issues.length > 0) {
        throw new Error(`Invalid menu node: ${validation.issues.join("; ")}`);
      }
      const result = applyMenuAddNode(Array.isArray(menu.payload) ? menu.payload : [], parentId, nodeData);

      if (dryRun) {
        return {
          content: [
            {
              type: "text",
              text: JSON.stringify({ success: true, dryRun: true, operation: "add_menu_node", nodeId: result.nodeId, warnings: validation.warnings, preview: result.payload }, null, 2)
            }
          ]
        };
      }

      await api.put(`/menus/main`, { payload: result.payload, items: menu.items || [] });
      return { content: [{ type: "text", text: JSON.stringify({ success: true, nodeId: result.nodeId, payload: result.payload }, null, 2) }] };
    }
    case "update_menu_translation": {
      const { nodeId, translations } = params;
      const dryRun = !!params.dryRun;
      const validation = validateMenuTranslations(translations);
      if (validation.issues.length > 0) {
        throw new Error(`Invalid translations: ${validation.issues.join("; ")}`);
      }
      const res = await api.get(`/menus/main`);
      const menu = res.data;
      const result = applyMenuUpdateTranslation(Array.isArray(menu.payload) ? menu.payload : [], nodeId, translations);

      if (dryRun) {
        return {
          content: [
            {
              type: "text",
              text: JSON.stringify({ success: true, dryRun: true, operation: "update_menu_translation", warnings: validation.warnings, preview: result.payload }, null, 2)
            }
          ]
        };
      }

      await api.put(`/menus/main`, { payload: result.payload, items: menu.items || [] });
      return { content: [{ type: "text", text: JSON.stringify({ success: true, nodeId, payload: result.payload }, null, 2) }] };
    }
    case "move_menu_node": {
      const { nodeId, newParentId, orderIndex } = params;
      const dryRun = !!params.dryRun;
      const res = await api.get(`/menus/main`);
      const menu = res.data;
      const result = applyMenuMoveNode(Array.isArray(menu.payload) ? menu.payload : [], nodeId, newParentId, orderIndex);

      if (dryRun) {
        return {
          content: [
            {
              type: "text",
              text: JSON.stringify({ success: true, dryRun: true, operation: "move_menu_node", preview: result.payload }, null, 2)
            }
          ]
        };
      }

      await api.put(`/menus/main`, { payload: result.payload, items: menu.items || [] });
      return { content: [{ type: "text", text: JSON.stringify({ success: true, payload: result.payload }, null, 2) }] };
    }
    case "remove_menu_node": {
      const { nodeId } = params;
      const dryRun = !!params.dryRun;
      const res = await api.get(`/menus/main`);
      const menu = res.data;
      const result = applyMenuRemoveNode(Array.isArray(menu.payload) ? menu.payload : [], nodeId);

      if (dryRun) {
        return {
          content: [
            {
              type: "text",
              text: JSON.stringify({ success: true, dryRun: true, operation: "remove_menu_node", removedNode: result.removedNode, preview: result.payload }, null, 2)
            }
          ]
        };
      }

      await api.put(`/menus/main`, { payload: result.payload, items: menu.items || [] });
      return { content: [{ type: "text", text: JSON.stringify({ success: true, payload: result.payload }, null, 2) }] };
    }
    default:
      return null;
  }
}