import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { ERPNextClient, truncateResponse, formatDocumentMarkdown, formatListMarkdown } from "../services/erpnext-client.js";
import {
  ListDocumentsSchema,
  GetDocumentSchema,
  CreateDocumentSchema,
  UpdateDocumentSchema,
  DeleteDocumentSchema,
  SubmitDocumentSchema,
  CancelDocumentSchema,
  SearchLinkSchema,
  GetCountSchema,
  CallMethodSchema,
  GetDocTypeMetaSchema,
  RunReportSchema,
  BulkUpdateSchema,
  WorkflowActionSchema,
} from "../schemas/common.js";

export function registerCoreTools(server: McpServer, client: ERPNextClient): void {

  // ─── 1. List Documents ─────────────────────────────────
  server.registerTool(
    "erpnext_list_documents",
    {
      title: "List ERPNext Documents",
      description: `List documents of any DocType with filtering, sorting, pagination and field selection.

Args:
  - doctype: DocType name (e.g. "Sales Order", "Customer", "Item")
  - fields: Array of field names to return (default: ["name"])
  - filters: Array of [field, operator, value] tuples (e.g. [["status","=","Open"]])
  - order_by: Sort string (e.g. "modified desc")
  - group_by: Group results by field
  - limit: Max results (1-100, default 20)
  - offset: Skip N results for pagination

Returns: Paginated list with total count, items array, and pagination metadata.

Examples:
  - List open sales orders: doctype="Sales Order", filters=[["status","=","To Deliver and Bill"]]
  - List customers: doctype="Customer", fields=["name","customer_name","territory"]
  - List items by group: doctype="Item", filters=[["item_group","=","Products"]]`,
      inputSchema: ListDocumentsSchema,
      annotations: { readOnlyHint: true, destructiveHint: false, idempotentHint: true, openWorldHint: true },
    },
    async (params) => {
      try {
        const result = await client.listDocuments(params.doctype, {
          fields: params.fields,
          filters: params.filters?.map(([f, op, val]) => [params.doctype, f, op, val as string]),
          order_by: params.order_by,
          group_by: params.group_by,
          limit_start: params.offset,
          limit_page_length: params.limit,
        });

        const text = formatListMarkdown(result.items, params.doctype, result);
        return { content: [{ type: "text", text: truncateResponse(text) }] };
      } catch (error) {
        return { isError: true, content: [{ type: "text", text: `Error: ${(error as Error).message}` }] };
      }
    }
  );

  // ─── 2. Get Document ───────────────────────────────────
  server.registerTool(
    "erpnext_get_document",
    {
      title: "Get ERPNext Document",
      description: `Retrieve a single document by DocType and name with all or selected fields.

Args:
  - doctype: DocType name
  - name: Document name/ID
  - fields: Optional array of specific fields to return

Returns: Full document data including child tables.`,
      inputSchema: GetDocumentSchema,
      annotations: { readOnlyHint: true, destructiveHint: false, idempotentHint: true, openWorldHint: true },
    },
    async (params) => {
      try {
        const doc = await client.getDocument(params.doctype, params.name, params.fields);
        const text = formatDocumentMarkdown(doc, params.doctype);
        return { content: [{ type: "text", text: truncateResponse(text) }] };
      } catch (error) {
        return { isError: true, content: [{ type: "text", text: `Error: ${(error as Error).message}` }] };
      }
    }
  );

  // ─── 3. Create Document ────────────────────────────────
  server.registerTool(
    "erpnext_create_document",
    {
      title: "Create ERPNext Document",
      description: `Create a new document of any DocType.

Args:
  - doctype: DocType name
  - data: Object with field values. For child tables, pass array of objects under the table fieldname.

Returns: Created document with assigned name.

Examples:
  - Create customer: doctype="Customer", data={"customer_name":"Acme Corp","customer_type":"Company","customer_group":"Commercial","territory":"All Territories"}
  - Create item: doctype="Item", data={"item_code":"ITEM-001","item_name":"Widget","item_group":"Products","stock_uom":"Nos"}`,
      inputSchema: CreateDocumentSchema,
      annotations: { readOnlyHint: false, destructiveHint: false, idempotentHint: false, openWorldHint: true },
    },
    async (params) => {
      try {
        const doc = await client.createDocument(params.doctype, params.data);
        return { content: [{ type: "text", text: `Created ${params.doctype}: ${doc.name}\n\n${formatDocumentMarkdown(doc, params.doctype)}` }] };
      } catch (error) {
        return { isError: true, content: [{ type: "text", text: `Error: ${(error as Error).message}` }] };
      }
    }
  );

  // ─── 4. Update Document ────────────────────────────────
  server.registerTool(
    "erpnext_update_document",
    {
      title: "Update ERPNext Document",
      description: `Update an existing document. Only pass the fields you want to change (PATCH semantics).

Args:
  - doctype: DocType name
  - name: Document name/ID
  - data: Object with fields to update

Returns: Updated document.`,
      inputSchema: UpdateDocumentSchema,
      annotations: { readOnlyHint: false, destructiveHint: false, idempotentHint: true, openWorldHint: true },
    },
    async (params) => {
      try {
        const doc = await client.updateDocument(params.doctype, params.name, params.data);
        return { content: [{ type: "text", text: `Updated ${params.doctype}: ${params.name}\n\n${formatDocumentMarkdown(doc, params.doctype)}` }] };
      } catch (error) {
        return { isError: true, content: [{ type: "text", text: `Error: ${(error as Error).message}` }] };
      }
    }
  );

  // ─── 5. Delete Document ────────────────────────────────
  server.registerTool(
    "erpnext_delete_document",
    {
      title: "Delete ERPNext Document",
      description: `Permanently delete a document. This cannot be undone.

Args:
  - doctype: DocType name
  - name: Document name/ID`,
      inputSchema: DeleteDocumentSchema,
      annotations: { readOnlyHint: false, destructiveHint: true, idempotentHint: false, openWorldHint: true },
    },
    async (params) => {
      try {
        await client.deleteDocument(params.doctype, params.name);
        return { content: [{ type: "text", text: `Deleted ${params.doctype}: ${params.name}` }] };
      } catch (error) {
        return { isError: true, content: [{ type: "text", text: `Error: ${(error as Error).message}` }] };
      }
    }
  );

  // ─── 6. Submit Document ────────────────────────────────
  server.registerTool(
    "erpnext_submit_document",
    {
      title: "Submit ERPNext Document",
      description: `Submit a submittable document (sets docstatus=1). Used for Sales Orders, Purchase Orders, Invoices, Journal Entries, etc. Submitted documents are locked from editing.

Args:
  - doctype: DocType name
  - name: Document name/ID`,
      inputSchema: SubmitDocumentSchema,
      annotations: { readOnlyHint: false, destructiveHint: false, idempotentHint: true, openWorldHint: true },
    },
    async (params) => {
      try {
        const doc = await client.submitDocument(params.doctype, params.name);
        return { content: [{ type: "text", text: `Submitted ${params.doctype}: ${params.name}\n\n${formatDocumentMarkdown(doc, params.doctype)}` }] };
      } catch (error) {
        return { isError: true, content: [{ type: "text", text: `Error: ${(error as Error).message}` }] };
      }
    }
  );

  // ─── 7. Cancel Document ────────────────────────────────
  server.registerTool(
    "erpnext_cancel_document",
    {
      title: "Cancel ERPNext Document",
      description: `Cancel a submitted document (sets docstatus=2). Creates reversal entries where applicable (e.g. GL entries for invoices).

Args:
  - doctype: DocType name
  - name: Document name/ID`,
      inputSchema: CancelDocumentSchema,
      annotations: { readOnlyHint: false, destructiveHint: true, idempotentHint: true, openWorldHint: true },
    },
    async (params) => {
      try {
        const doc = await client.cancelDocument(params.doctype, params.name);
        return { content: [{ type: "text", text: `Cancelled ${params.doctype}: ${params.name}` }] };
      } catch (error) {
        return { isError: true, content: [{ type: "text", text: `Error: ${(error as Error).message}` }] };
      }
    }
  );

  // ─── 8. Search Link ────────────────────────────────────
  server.registerTool(
    "erpnext_search_link",
    {
      title: "Search ERPNext Link",
      description: `Search for documents by text — the same search used in Link fields across ERPNext. Returns name + description pairs.

Args:
  - doctype: DocType to search in
  - txt: Search text
  - filters: Optional additional filters
  - page_length: Max results (default 20)

Examples:
  - Find customers matching "acme": doctype="Customer", txt="acme"
  - Find items matching "widget": doctype="Item", txt="widget"`,
      inputSchema: SearchLinkSchema,
      annotations: { readOnlyHint: true, destructiveHint: false, idempotentHint: true, openWorldHint: true },
    },
    async (params) => {
      try {
        const results = await client.searchLink(
          params.doctype, params.txt, params.filters, params.page_length
        );
        const text = results.length
          ? results.map((r) => `- **${r.value}** — ${r.description || ""}`).join("\n")
          : `No ${params.doctype} found matching "${params.txt}"`;
        return { content: [{ type: "text", text }] };
      } catch (error) {
        return { isError: true, content: [{ type: "text", text: `Error: ${(error as Error).message}` }] };
      }
    }
  );

  // ─── 9. Get Count ──────────────────────────────────────
  server.registerTool(
    "erpnext_get_count",
    {
      title: "Count ERPNext Documents",
      description: `Get the total count of documents matching optional filters.

Args:
  - doctype: DocType name
  - filters: Optional [field, operator, value] tuples

Examples:
  - Count open sales orders: doctype="Sales Order", filters=[["status","=","To Deliver and Bill"]]
  - Count all customers: doctype="Customer"`,
      inputSchema: GetCountSchema,
      annotations: { readOnlyHint: true, destructiveHint: false, idempotentHint: true, openWorldHint: true },
    },
    async (params) => {
      try {
        const count = await client.getCount(
          params.doctype,
          params.filters?.map(([f, op, val]) => [params.doctype, f, op, val as string])
        );
        return { content: [{ type: "text", text: `Count of ${params.doctype}: ${count}` }] };
      } catch (error) {
        return { isError: true, content: [{ type: "text", text: `Error: ${(error as Error).message}` }] };
      }
    }
  );

  // ─── 10. Call Method ───────────────────────────────────
  server.registerTool(
    "erpnext_call_method",
    {
      title: "Call ERPNext Method",
      description: `Call any whitelisted ERPNext/Frappe method via the /api/method/ endpoint. This is the escape hatch for any operation not covered by the other tools.

Args:
  - method: Dotted method path (e.g. "erpnext.stock.utils.get_stock_balance")
  - args: Method arguments as key-value object

Common methods:
  - frappe.client.get_value: Get a field value from a document
  - frappe.client.set_value: Set a field value on a document
  - frappe.client.get_list: Alternative list with more options
  - erpnext.stock.utils.get_stock_balance: Get stock balance for item/warehouse
  - erpnext.setup.utils.get_exchange_rate: Get currency exchange rate
  - erpnext.selling.page.point_of_sale.point_of_sale.get_items: POS items
  - erpnext.stock.get_item_details.get_item_details: Full item details for transactions`,
      inputSchema: CallMethodSchema,
      annotations: { readOnlyHint: false, destructiveHint: false, idempotentHint: false, openWorldHint: true },
    },
    async (params) => {
      try {
        const result = await client.callMethod(params.method, params.args);
        const text = typeof result === "string" ? result : JSON.stringify(result, null, 2);
        return { content: [{ type: "text", text: truncateResponse(text) }] };
      } catch (error) {
        return { isError: true, content: [{ type: "text", text: `Error: ${(error as Error).message}` }] };
      }
    }
  );

  // ─── 11. Get DocType Schema ────────────────────────────
  server.registerTool(
    "erpnext_get_doctype_meta",
    {
      title: "Get DocType Schema/Meta",
      description: `Get the field definitions and schema for any DocType. Useful to discover available fields before listing or creating documents.

Args:
  - doctype: DocType name

Returns: List of fields with fieldname, fieldtype, label, options, reqd (required), read_only, hidden.`,
      inputSchema: GetDocTypeMetaSchema,
      annotations: { readOnlyHint: true, destructiveHint: false, idempotentHint: true, openWorldHint: true },
    },
    async (params) => {
      try {
        const meta = await client.getDocTypeMeta(params.doctype);
        const text = JSON.stringify(meta, null, 2);
        return { content: [{ type: "text", text: truncateResponse(text) }] };
      } catch (error) {
        return { isError: true, content: [{ type: "text", text: `Error: ${(error as Error).message}` }] };
      }
    }
  );

  // ─── 12. Run Report ────────────────────────────────────
  server.registerTool(
    "erpnext_run_report",
    {
      title: "Run ERPNext Report",
      description: `Run a Script Report or Query Report and return the data.

Args:
  - report_name: Name of the report (e.g. "General Ledger", "Stock Balance", "Accounts Receivable")
  - filters: Report filter parameters as key-value object

Examples:
  - General Ledger: report_name="General Ledger", filters={"company":"My Company","from_date":"2024-01-01","to_date":"2024-12-31"}
  - Stock Balance: report_name="Stock Balance", filters={"company":"My Company"}
  - Accounts Receivable: report_name="Accounts Receivable", filters={"company":"My Company"}`,
      inputSchema: RunReportSchema,
      annotations: { readOnlyHint: true, destructiveHint: false, idempotentHint: true, openWorldHint: true },
    },
    async (params) => {
      try {
        const result = await client.runReport(params.report_name, params.filters);
        const text = JSON.stringify(result, null, 2);
        return { content: [{ type: "text", text: truncateResponse(text) }] };
      } catch (error) {
        return { isError: true, content: [{ type: "text", text: `Error: ${(error as Error).message}` }] };
      }
    }
  );

  // ─── 13. List DocTypes ─────────────────────────────────
  server.registerTool(
    "erpnext_list_doctypes",
    {
      title: "List Available DocTypes",
      description: `List all available DocTypes in the ERPNext instance. Useful to discover what entities exist.

Returns: Array of DocType names sorted alphabetically.`,
      inputSchema: {},
      annotations: { readOnlyHint: true, destructiveHint: false, idempotentHint: true, openWorldHint: true },
    },
    async () => {
      try {
        const doctypes = await client.getDocTypeList();
        return { content: [{ type: "text", text: `Available DocTypes (${doctypes.length}):\n\n${doctypes.join("\n")}` }] };
      } catch (error) {
        return { isError: true, content: [{ type: "text", text: `Error: ${(error as Error).message}` }] };
      }
    }
  );

  // ─── 14. Bulk Update ───────────────────────────────────
  server.registerTool(
    "erpnext_bulk_update",
    {
      title: "Bulk Update ERPNext Documents",
      description: `Update multiple documents of the same DocType with the same field values.

Args:
  - doctype: DocType name
  - names: Array of document names to update
  - data: Field values to set on all documents

Example: Set status on multiple issues: doctype="Issue", names=["ISS-001","ISS-002"], data={"status":"Closed"}`,
      inputSchema: BulkUpdateSchema,
      annotations: { readOnlyHint: false, destructiveHint: false, idempotentHint: true, openWorldHint: true },
    },
    async (params) => {
      try {
        const results: string[] = [];
        const errors: string[] = [];
        for (const name of params.names) {
          try {
            await client.updateDocument(params.doctype, name, params.data);
            results.push(name);
          } catch (error) {
            errors.push(`${name}: ${(error as Error).message}`);
          }
        }
        let text = `Updated ${results.length}/${params.names.length} ${params.doctype} documents.`;
        if (errors.length) {
          text += `\n\nErrors:\n${errors.join("\n")}`;
        }
        return { content: [{ type: "text", text }] };
      } catch (error) {
        return { isError: true, content: [{ type: "text", text: `Error: ${(error as Error).message}` }] };
      }
    }
  );

  // ─── 15. Workflow Action ───────────────────────────────
  server.registerTool(
    "erpnext_workflow_action",
    {
      title: "Apply Workflow Action",
      description: `Apply a workflow action to a document that has a workflow configured.

Args:
  - doctype: DocType name
  - name: Document name
  - action: Workflow action name (e.g. "Approve", "Reject", "Submit")`,
      inputSchema: WorkflowActionSchema,
      annotations: { readOnlyHint: false, destructiveHint: false, idempotentHint: false, openWorldHint: true },
    },
    async (params) => {
      try {
        const result = await client.callMethod("frappe.model.workflow.apply_workflow", {
          doc: { doctype: params.doctype, name: params.name },
          action: params.action,
        });
        return { content: [{ type: "text", text: `Applied workflow action "${params.action}" on ${params.doctype}: ${params.name}` }] };
      } catch (error) {
        return { isError: true, content: [{ type: "text", text: `Error: ${(error as Error).message}` }] };
      }
    }
  );
}