package api

import (
	"encoding/json"
	"errors"
	"fmt"
	"net/http"
	"sort"
	"strings"

	"github.com/sandrodach/mindsift/internal/auth"
	"github.com/sandrodach/mindsift/internal/domain"
	"github.com/sandrodach/mindsift/internal/storage"
)

// MCP (Model Context Protocol) endpoint for AI agents: Streamable HTTP, stateless, JSON-RPC 2.0 over
// POST. Authentication runs through authMiddleware (API key with agent scopes or a session); every
// tool checks the scope it needs (mcpToolAllowed). There is no server-to-client stream (GET answers
// 405), so each request is one JSON response.

const mcpPath = "/api/v1/mcp"

// Version of the tool set, not of MindSift (the binary does not know its release)
const mcpServerVersion = "1"

// Protocol versions this server speaks; the newest is the default
var mcpProtocolVersions = []string{"2025-06-18", "2025-03-26", "2024-11-05"}

type jsonrpcRequest struct {
	JSONRPC string          `json:"jsonrpc"`
	ID      json.RawMessage `json:"id,omitempty"`
	Method  string          `json:"method"`
	Params  json.RawMessage `json:"params,omitempty"`
}

type jsonrpcError struct {
	Code    int    `json:"code"`
	Message string `json:"message"`
}

type jsonrpcResponse struct {
	JSONRPC string          `json:"jsonrpc"`
	ID      json.RawMessage `json:"id"`
	Result  interface{}     `json:"result,omitempty"`
	Error   *jsonrpcError   `json:"error,omitempty"`
}

const (
	rpcParseError     = -32700
	rpcInvalidRequest = -32600
	rpcMethodNotFound = -32601
	rpcInvalidParams  = -32602
)

// mcpTool is one callable tool: the scope an API key needs for it and the function doing the work.
// run returns the structured result; an error becomes a tool error (isError) the agent can read.
type mcpTool struct {
	Name        string
	Description string
	Scope       string
	Schema      map[string]interface{}
	run         func(s *Server, userID string, args json.RawMessage) (interface{}, error)
}

// mcpToolAllowed: sessions may use every tool, API keys only those of their scopes. search needs any
// read scope (its results are filtered to those scopes).
func mcpToolAllowed(scopes []string, isKey bool, tool mcpTool) bool {
	if !isKey {
		return true
	}
	if tool.Scope == "" {
		return true
	}
	has := func(sc string) bool {
		for _, have := range scopes {
			if have == sc {
				return true
			}
		}
		return false
	}
	if tool.Name == "search" {
		return has(storage.ScopeTasksRead) || has(storage.ScopeListsRead)
	}
	return has(tool.Scope)
}

func (s *Server) handleMCP(w http.ResponseWriter, r *http.Request) {
	userID := auth.GetUserID(r.Context())
	scopes, isKey := r.Context().Value(apiKeyScopesKey{}).([]string)

	var raw json.RawMessage
	if err := json.NewDecoder(r.Body).Decode(&raw); err != nil {
		writeRPC(w, nil, nil, &jsonrpcError{rpcParseError, "Ungültiges JSON"})
		return
	}
	trimmed := strings.TrimSpace(string(raw))
	if strings.HasPrefix(trimmed, "[") {
		writeRPC(w, nil, nil, &jsonrpcError{rpcInvalidRequest, "Batch-Anfragen werden nicht unterstützt"})
		return
	}
	var req jsonrpcRequest
	if err := json.Unmarshal(raw, &req); err != nil || req.Method == "" {
		writeRPC(w, nil, nil, &jsonrpcError{rpcInvalidRequest, "Ungültige JSON-RPC-Anfrage"})
		return
	}
	// Notifications (no id) are acknowledged without a body
	if len(req.ID) == 0 || string(req.ID) == "null" {
		w.WriteHeader(http.StatusAccepted)
		return
	}

	switch req.Method {
	case "initialize":
		var p struct {
			ProtocolVersion string `json:"protocolVersion"`
		}
		_ = json.Unmarshal(req.Params, &p)
		version := mcpProtocolVersions[0]
		for _, v := range mcpProtocolVersions {
			if v == p.ProtocolVersion {
				version = v
			}
		}
		writeRPC(w, req.ID, map[string]interface{}{
			"protocolVersion": version,
			"capabilities":    map[string]interface{}{"tools": map[string]interface{}{}},
			"serverInfo":      map[string]string{"name": "MindSift", "version": mcpServerVersion},
			"instructions": "MindSift is a personal notes, tasks and lists app. Use list_task_lists and list_tasks " +
				"to see open tasks, complete_task to check one off, list_lists/get_list for shopping and other " +
				"lists and check_list_item to tick items. IDs come from the list tools; never guess them. " +
				"Entries you create or change are marked for the user until they touch them.",
		}, nil)
	case "ping":
		writeRPC(w, req.ID, map[string]interface{}{}, nil)
	case "tools/list":
		tools := []map[string]interface{}{}
		for _, t := range mcpTools {
			if !mcpToolAllowed(scopes, isKey, t) {
				continue
			}
			tools = append(tools, map[string]interface{}{
				"name":        t.Name,
				"description": t.Description,
				"inputSchema": t.Schema,
			})
		}
		writeRPC(w, req.ID, map[string]interface{}{"tools": tools}, nil)
	case "tools/call":
		var p struct {
			Name      string          `json:"name"`
			Arguments json.RawMessage `json:"arguments"`
		}
		if err := json.Unmarshal(req.Params, &p); err != nil || p.Name == "" {
			writeRPC(w, req.ID, nil, &jsonrpcError{rpcInvalidParams, "Parameter 'name' fehlt"})
			return
		}
		tool, ok := mcpToolByName(p.Name)
		if !ok {
			writeRPC(w, req.ID, nil, &jsonrpcError{rpcInvalidParams, "Unbekanntes Tool: " + p.Name})
			return
		}
		if !mcpToolAllowed(scopes, isKey, tool) {
			writeRPC(w, req.ID, toolError("Der API-Key hat keine Berechtigung für "+tool.Name+" (Scope "+tool.Scope+" fehlt)"), nil)
			return
		}
		if len(p.Arguments) == 0 {
			p.Arguments = json.RawMessage("{}")
		}
		result, err := tool.run(s, userID, p.Arguments)
		if err != nil {
			writeRPC(w, req.ID, toolError(err.Error()), nil)
			return
		}
		if tool.Name == "search" && isKey {
			result = filterSearchForScopes(result, scopes)
		}
		writeRPC(w, req.ID, toolResult(result), nil)
	default:
		writeRPC(w, req.ID, nil, &jsonrpcError{rpcMethodNotFound, "Methode nicht unterstützt: " + req.Method})
	}
}

// handleMCPNoStream: the endpoint is stateless and has no server-initiated stream (GET) or session to
// end (DELETE).
func handleMCPNoStream(w http.ResponseWriter, _ *http.Request) {
	w.Header().Set("Allow", "POST")
	writeError(w, http.StatusMethodNotAllowed, "Der MCP-Endpunkt nimmt nur POST an (kein Server-Stream)")
}

func writeRPC(w http.ResponseWriter, id json.RawMessage, result interface{}, rpcErr *jsonrpcError) {
	if len(id) == 0 {
		id = json.RawMessage("null")
	}
	writeJSON(w, http.StatusOK, jsonrpcResponse{JSONRPC: "2.0", ID: id, Result: result, Error: rpcErr})
}

// toolResult: the data as structuredContent plus the same JSON as text for clients without
// structured output.
func toolResult(data interface{}) map[string]interface{} {
	text, _ := json.MarshalIndent(data, "", "  ")
	return map[string]interface{}{
		"content":           []map[string]string{{"type": "text", "text": string(text)}},
		"structuredContent": wrapStructured(data),
	}
}

// structuredContent must be an object; arrays are wrapped
func wrapStructured(data interface{}) interface{} {
	raw, _ := json.Marshal(data)
	if strings.HasPrefix(strings.TrimSpace(string(raw)), "[") {
		return map[string]interface{}{"items": data}
	}
	return data
}

func toolError(msg string) map[string]interface{} {
	return map[string]interface{}{
		"content": []map[string]string{{"type": "text", "text": msg}},
		"isError": true,
	}
}

// --- tools ---

func mcpToolByName(name string) (mcpTool, bool) {
	for _, t := range mcpTools {
		if t.Name == name {
			return t, true
		}
	}
	return mcpTool{}, false
}

func schema(required []string, props map[string]interface{}) map[string]interface{} {
	out := map[string]interface{}{"type": "object", "properties": props}
	if len(required) > 0 {
		out["required"] = required
	}
	return out
}

func prop(typ, desc string) map[string]interface{} {
	return map[string]interface{}{"type": typ, "description": desc}
}

func decodeArgs(args json.RawMessage, into interface{}) error {
	if err := json.Unmarshal(args, into); err != nil {
		return errors.New("Ungültige Argumente: " + err.Error())
	}
	return nil
}

// taskView is what an agent gets per task: the fields it can reason about, no internal bookkeeping.
type taskView struct {
	ID           string           `json:"id"`
	Content      string           `json:"content"`
	IsCompleted  bool             `json:"isCompleted"`
	Priority     string           `json:"priority"`
	DueDate      string           `json:"dueDate,omitempty"`
	TaskListID   string           `json:"taskListId,omitempty"`
	KanbanStatus string           `json:"kanbanStatus,omitempty"`
	Notes        string           `json:"notes,omitempty"`
	Tags         []string         `json:"tags,omitempty"`
	Subtasks     []domain.SubTask `json:"subtasks,omitempty"`
	Recurrence   string           `json:"recurrence,omitempty"`
	CreatedAt    string           `json:"createdAt"`
}

func toTaskView(t *domain.Thought) taskView {
	return taskView{
		ID: t.ID, Content: t.Content, IsCompleted: t.IsCompleted, Priority: t.Priority, DueDate: t.DueDate,
		TaskListID: t.TaskListID, KanbanStatus: t.KanbanStatus, Notes: t.Notes, Tags: t.Tags, Subtasks: t.Subtasks,
		Recurrence: t.Recurrence, CreatedAt: t.CreatedAt,
	}
}

type taskListView struct {
	ID         string       `json:"id"`
	Title      string       `json:"title"`
	Icon       string       `json:"icon,omitempty"`
	Permission string       `json:"permission"`
	OpenTasks  int          `json:"openTasks"`
	Columns    []columnView `json:"columns,omitempty"`
}

// columnView: a board column, so an agent knows the valid kanbanStatus values of a task list
type columnView struct {
	ID     string `json:"id"`
	Name   string `json:"name"`
	IsDone bool   `json:"isDone,omitempty"`
}

func toTaskListView(l domain.TaskList) taskListView {
	cols := make([]columnView, 0, len(l.Columns))
	for _, c := range l.Columns {
		cols = append(cols, columnView{ID: c.ID, Name: c.Name, IsDone: c.IsDone})
	}
	permission := l.Permission
	if permission == "" && l.IsOwner {
		permission = "owner"
	}
	return taskListView{ID: l.ID, Title: l.Title, Icon: l.Icon, Permission: permission, OpenTasks: l.TasksCount, Columns: cols}
}

type listView struct {
	ID        string `json:"id"`
	Title     string `json:"title"`
	Icon      string `json:"icon,omitempty"`
	ListType  string `json:"listType"`
	Role      string `json:"role"`
	OpenItems int    `json:"openItems"`
	Items     int    `json:"items"`
}

func toListView(l domain.SharedList) listView {
	open := 0
	for _, it := range l.Items {
		if !it.IsCompleted {
			open++
		}
	}
	role := l.Role
	if l.IsOwner {
		role = "owner"
	}
	return listView{ID: l.ID, Title: l.Title, Icon: l.Icon, ListType: l.ListType, Role: role, OpenItems: open, Items: len(l.Items)}
}

var mcpTools = []mcpTool{
	{
		Name:        "list_task_lists",
		Description: "All task lists the user can see, with permission (owner/editor/viewer), the number of open tasks and the board columns (valid kanbanStatus values). Tasks without a list live in the personal inbox list (taskListId empty).",
		Scope:       storage.ScopeTasksRead,
		Schema:      schema(nil, map[string]interface{}{}),
		run: func(s *Server, userID string, _ json.RawMessage) (interface{}, error) {
			lists, err := s.store.GetTaskLists(userID)
			if err != nil {
				return nil, err
			}
			out := make([]taskListView, 0, len(lists))
			for _, l := range lists {
				out = append(out, toTaskListView(l))
			}
			return out, nil
		},
	},
	{
		Name:        "create_task_list",
		Description: "Create a personal task list (board with the default columns). Returns it with its id and columns.",
		Scope:       storage.ScopeTasksWrite,
		Schema: schema([]string{"title"}, map[string]interface{}{
			"title": prop("string", "Name of the task list"),
			"icon":  prop("string", "One emoji, optional (default 📋)"),
		}),
		run: func(s *Server, userID string, args json.RawMessage) (interface{}, error) {
			var a struct {
				Title string `json:"title"`
				Icon  string `json:"icon"`
			}
			if err := decodeArgs(args, &a); err != nil {
				return nil, err
			}
			if strings.TrimSpace(a.Title) == "" {
				return nil, errors.New("'title' darf nicht leer sein")
			}
			tl, err := s.store.CreateTaskList(userID, "", "", a.Title, a.Icon, "")
			if err != nil {
				return nil, err
			}
			s.broadcastTaskListChange(tl.ID, nil, "TASK_LIST_CREATED")
			tl.IsOwner = true
			return toTaskListView(*tl), nil
		},
	},
	{
		Name:        "list_tasks",
		Description: "Tasks the user can see. Defaults to open tasks across all lists; filter by taskListId, status (open|done|all) or dueBefore (YYYY-MM-DD, inclusive). Sorted: overdue and due first.",
		Scope:       storage.ScopeTasksRead,
		Schema: schema(nil, map[string]interface{}{
			"taskListId": prop("string", "Only tasks of this task list"),
			"status":     map[string]interface{}{"type": "string", "enum": []string{"open", "done", "all"}, "description": "Default open"},
			"dueBefore":  prop("string", "Only tasks due on or before this date (YYYY-MM-DD); tasks without due date are left out"),
			"limit":      prop("integer", "Maximum number of tasks (default 100)"),
		}),
		run: func(s *Server, userID string, args json.RawMessage) (interface{}, error) {
			var a struct {
				TaskListID string `json:"taskListId"`
				Status     string `json:"status"`
				DueBefore  string `json:"dueBefore"`
				Limit      int    `json:"limit"`
			}
			if err := decodeArgs(args, &a); err != nil {
				return nil, err
			}
			tasks, err := s.store.GetTasks(userID, a.TaskListID)
			if err != nil {
				return nil, err
			}
			if a.Limit <= 0 {
				a.Limit = 100
			}
			out := make([]taskView, 0)
			for i := range tasks {
				t := &tasks[i]
				switch a.Status {
				case "done":
					if !t.IsCompleted {
						continue
					}
				case "all":
				default:
					if t.IsCompleted {
						continue
					}
				}
				if a.DueBefore != "" && (t.DueDate == "" || t.DueDate[:min(10, len(t.DueDate))] > a.DueBefore) {
					continue
				}
				out = append(out, toTaskView(t))
			}
			// Due dates first (earliest on top), then the rest in list order
			sort.SliceStable(out, func(i, j int) bool {
				if (out[i].DueDate == "") != (out[j].DueDate == "") {
					return out[i].DueDate != ""
				}
				return out[i].DueDate != "" && out[i].DueDate < out[j].DueDate
			})
			if len(out) > a.Limit {
				out = out[:a.Limit]
			}
			return out, nil
		},
	},
	{
		Name:        "get_task",
		Description: "One task with all details.",
		Scope:       storage.ScopeTasksRead,
		Schema:      schema([]string{"id"}, map[string]interface{}{"id": prop("string", "Task id")}),
		run: func(s *Server, userID string, args json.RawMessage) (interface{}, error) {
			var a struct {
				ID string `json:"id"`
			}
			if err := decodeArgs(args, &a); err != nil {
				return nil, err
			}
			t, err := s.store.GetThoughtByID(userID, a.ID)
			if err != nil || t == nil {
				return nil, errors.New("Aufgabe nicht gefunden")
			}
			return toTaskView(t), nil
		},
	},
	{
		Name:        "create_task",
		Description: "Create a task, optionally in a task list the user may edit. dueDate as YYYY-MM-DD or YYYY-MM-DDTHH:MM.",
		Scope:       storage.ScopeTasksWrite,
		Schema: schema([]string{"content"}, map[string]interface{}{
			"content":    prop("string", "Task text; #hashtags become tags"),
			"taskListId": prop("string", "Task list id (from list_task_lists); empty = personal tasks"),
			"priority":   map[string]interface{}{"type": "string", "enum": []string{"low", "normal", "high", "urgent"}},
			"dueDate":    prop("string", "YYYY-MM-DD or YYYY-MM-DDTHH:MM"),
			"notes":      prop("string", "Longer description"),
		}),
		run: func(s *Server, userID string, args json.RawMessage) (interface{}, error) {
			var a struct {
				Content    string `json:"content"`
				TaskListID string `json:"taskListId"`
				Priority   string `json:"priority"`
				DueDate    string `json:"dueDate"`
				Notes      string `json:"notes"`
			}
			if err := decodeArgs(args, &a); err != nil {
				return nil, err
			}
			if strings.TrimSpace(a.Content) == "" {
				return nil, errors.New("'content' darf nicht leer sein")
			}
			t, err := s.createTask(userID, a.Content, a.Priority, "agent", a.DueDate, a.TaskListID, a.Notes)
			if err != nil {
				return nil, err
			}
			return toTaskView(t), nil
		},
	},
	{
		Name:        "update_task",
		Description: "Change fields of a task; only the given fields change. Empty dueDate removes the due date.",
		Scope:       storage.ScopeTasksWrite,
		Schema: schema([]string{"id"}, map[string]interface{}{
			"id":           prop("string", "Task id"),
			"content":      prop("string", "New text"),
			"isCompleted":  prop("boolean", "true = done"),
			"dueDate":      prop("string", "YYYY-MM-DD, YYYY-MM-DDTHH:MM or empty"),
			"priority":     map[string]interface{}{"type": "string", "enum": []string{"low", "normal", "high", "urgent"}},
			"notes":        prop("string", "Description"),
			"kanbanStatus": prop("string", "Column id of the task list's board (e.g. todo, in_progress, done)"),
			"taskListId":   prop("string", "Move into another task list"),
			"tags":         map[string]interface{}{"type": "array", "items": map[string]string{"type": "string"}},
		}),
		run: func(s *Server, userID string, args json.RawMessage) (interface{}, error) {
			var a struct {
				ID string `json:"id"`
				taskPatch
			}
			if err := decodeArgs(args, &a); err != nil {
				return nil, err
			}
			a.taskPatch.Assignees, a.taskPatch.Recurrence, a.taskPatch.Subtasks = nil, nil, nil
			a.taskPatch.byAgent = true
			t, err := s.updateTask(userID, a.ID, a.taskPatch)
			if err != nil {
				return nil, err
			}
			return toTaskView(t), nil
		},
	},
	{
		Name:        "complete_task",
		Description: "Check a task off (or reopen it with completed=false). Recurring tasks move to their next date.",
		Scope:       storage.ScopeTasksWrite,
		Schema: schema([]string{"id"}, map[string]interface{}{
			"id":        prop("string", "Task id"),
			"completed": prop("boolean", "Default true"),
		}),
		run: func(s *Server, userID string, args json.RawMessage) (interface{}, error) {
			var a struct {
				ID        string `json:"id"`
				Completed *bool  `json:"completed"`
			}
			if err := decodeArgs(args, &a); err != nil {
				return nil, err
			}
			done := a.Completed == nil || *a.Completed
			t, err := s.updateTask(userID, a.ID, taskPatch{IsCompleted: &done, byAgent: true})
			if err != nil {
				return nil, err
			}
			return toTaskView(t), nil
		},
	},
	{
		Name:        "delete_task",
		Description: "Delete a task for good, e.g. one created by mistake. Prefer complete_task for work that is done.",
		Scope:       storage.ScopeTasksWrite,
		Schema:      schema([]string{"id"}, map[string]interface{}{"id": prop("string", "Task id")}),
		run: func(s *Server, userID string, args json.RawMessage) (interface{}, error) {
			var a struct {
				ID string `json:"id"`
			}
			if err := decodeArgs(args, &a); err != nil {
				return nil, err
			}
			if _, err := s.store.GetThoughtByID(userID, a.ID); err != nil {
				return nil, errors.New("Aufgabe nicht gefunden")
			}
			if err := s.deleteTask(userID, a.ID); err != nil {
				return nil, err
			}
			return map[string]interface{}{"id": a.ID, "deleted": true}, nil
		},
	},
	{
		Name:        "list_lists",
		Description: "Shopping lists, checklists and other shared lists the user can see, with open/total item counts.",
		Scope:       storage.ScopeListsRead,
		Schema:      schema(nil, map[string]interface{}{}),
		run: func(s *Server, userID string, _ json.RawMessage) (interface{}, error) {
			lists, err := s.store.GetAllListsForUser(userID)
			if err != nil {
				return nil, err
			}
			out := make([]listView, 0, len(lists))
			for _, l := range lists {
				out = append(out, toListView(l))
			}
			return out, nil
		},
	},
	{
		Name:        "create_list",
		Description: "Create a list for the user: shopping (items grouped by category), checklist or vacation (packing list).",
		Scope:       storage.ScopeListsWrite,
		Schema: schema([]string{"title"}, map[string]interface{}{
			"title":    prop("string", "Name of the list"),
			"icon":     prop("string", "One emoji, optional"),
			"listType": map[string]interface{}{"type": "string", "enum": []string{"shopping", "checklist", "vacation"}, "description": "Default shopping"},
		}),
		run: func(s *Server, userID string, args json.RawMessage) (interface{}, error) {
			var a struct {
				Title    string `json:"title"`
				Icon     string `json:"icon"`
				ListType string `json:"listType"`
			}
			if err := decodeArgs(args, &a); err != nil {
				return nil, err
			}
			if strings.TrimSpace(a.Title) == "" {
				return nil, errors.New("'title' darf nicht leer sein")
			}
			l, err := s.store.CreateList(userID, a.Title, a.Icon, a.ListType)
			if err != nil {
				return nil, err
			}
			s.wsHub.BroadcastListEvent(l.ID, "LIST_CREATED", l)
			return toListView(*l), nil
		},
	},
	{
		Name:        "get_list",
		Description: "One list with all its items (id, content, category, quantity, isCompleted).",
		Scope:       storage.ScopeListsRead,
		Schema:      schema([]string{"listId"}, map[string]interface{}{"listId": prop("string", "List id from list_lists")}),
		run: func(s *Server, userID string, args json.RawMessage) (interface{}, error) {
			var a struct {
				ListID string `json:"listId"`
			}
			if err := decodeArgs(args, &a); err != nil {
				return nil, err
			}
			l, err := s.store.GetListByID(userID, a.ListID)
			if err != nil || l == nil {
				return nil, errors.New("Liste nicht gefunden")
			}
			return map[string]interface{}{"list": toListView(*l), "items": l.Items}, nil
		},
	},
	{
		Name:        "add_list_item",
		Description: "Add an item to a list the user may edit.",
		Scope:       storage.ScopeListsWrite,
		Schema: schema([]string{"listId", "content"}, map[string]interface{}{
			"listId":   prop("string", "List id"),
			"content":  prop("string", "Item text"),
			"category": prop("string", "Category/aisle, e.g. Obst"),
			"quantity": prop("string", "Amount, e.g. 2 or 500 g"),
		}),
		run: func(s *Server, userID string, args json.RawMessage) (interface{}, error) {
			var a struct {
				ListID, Content, Category, Quantity string
			}
			if err := decodeArgs(args, &a); err != nil {
				return nil, err
			}
			if strings.TrimSpace(a.Content) == "" {
				return nil, errors.New("'content' darf nicht leer sein")
			}
			return s.addListItem(userID, a.ListID, a.Content, a.Category, a.Quantity, true)
		},
	},
	{
		Name:        "check_list_item",
		Description: "Tick an item off a list (or untick it with completed=false).",
		Scope:       storage.ScopeListsWrite,
		Schema: schema([]string{"listId", "itemId"}, map[string]interface{}{
			"listId":    prop("string", "List id"),
			"itemId":    prop("string", "Item id from get_list"),
			"completed": prop("boolean", "Default true"),
		}),
		run: func(s *Server, userID string, args json.RawMessage) (interface{}, error) {
			var a struct {
				ListID    string `json:"listId"`
				ItemID    string `json:"itemId"`
				Completed *bool  `json:"completed"`
			}
			if err := decodeArgs(args, &a); err != nil {
				return nil, err
			}
			return s.setListItemDone(userID, a.ListID, a.ItemID, a.Completed == nil || *a.Completed, true)
		},
	},
	{
		Name:        "update_list_item",
		Description: "Change text, category or quantity of a list item; only the given fields change.",
		Scope:       storage.ScopeListsWrite,
		Schema: schema([]string{"listId", "itemId"}, map[string]interface{}{
			"listId":   prop("string", "List id"),
			"itemId":   prop("string", "Item id"),
			"content":  prop("string", "New text"),
			"category": prop("string", "New category"),
			"quantity": prop("string", "New amount"),
		}),
		run: func(s *Server, userID string, args json.RawMessage) (interface{}, error) {
			var a struct {
				ListID   string  `json:"listId"`
				ItemID   string  `json:"itemId"`
				Content  *string `json:"content"`
				Category *string `json:"category"`
				Quantity *string `json:"quantity"`
			}
			if err := decodeArgs(args, &a); err != nil {
				return nil, err
			}
			if err := s.store.EnsureListItemsWritable(userID, a.ListID, a.ItemID); err != nil {
				return nil, err
			}
			item, err := s.store.UpdateListItem(a.ItemID, a.Content, a.Category, a.Quantity)
			if err != nil {
				return nil, err
			}
			item.AgentMark = s.store.SetListItemAgentMark(a.ItemID, true)
			s.wsHub.BroadcastListEvent(a.ListID, "ITEM_UPDATED", item)
			return item, nil
		},
	},
	{
		Name:        "search",
		Description: "Full-text search over tasks and list items the user can see (notes are not included for API keys).",
		Scope:       storage.ScopeTasksRead,
		Schema:      schema([]string{"query"}, map[string]interface{}{"query": prop("string", "Words to search for")}),
		run: func(s *Server, userID string, args json.RawMessage) (interface{}, error) {
			var a struct {
				Query string `json:"query"`
			}
			if err := decodeArgs(args, &a); err != nil {
				return nil, err
			}
			res, err := s.store.SearchGlobal(userID, a.Query)
			if err != nil {
				return nil, err
			}
			tasks := make([]taskView, 0, len(res.Thoughts))
			for i := range res.Thoughts {
				tasks = append(tasks, toTaskView(&res.Thoughts[i]))
			}
			return map[string]interface{}{"tasks": tasks, "listItems": res.ListItems}, nil
		},
	},
	{
		Name:        "capture_to_inbox",
		Description: "Drop a thought into the user's inbox for later triage (not a task yet).",
		Scope:       storage.ScopeTriage,
		Schema: schema([]string{"content"}, map[string]interface{}{
			"content":  prop("string", "The thought"),
			"priority": map[string]interface{}{"type": "string", "enum": []string{"low", "normal", "high", "urgent"}},
			"dueDate":  prop("string", "YYYY-MM-DD, optional"),
		}),
		run: func(s *Server, userID string, args json.RawMessage) (interface{}, error) {
			var a struct {
				Content, Priority, DueDate string
			}
			if err := decodeArgs(args, &a); err != nil {
				return nil, err
			}
			if strings.TrimSpace(a.Content) == "" {
				return nil, errors.New("'content' darf nicht leer sein")
			}
			if a.Priority == "" {
				a.Priority = "normal"
			}
			t, err := s.store.CreateThought(userID, a.Content, a.Priority, "agent", a.DueDate)
			if err != nil {
				return nil, err
			}
			s.wsHub.BroadcastToUsers(s.taskAudience(t), "TASK_CREATED", t)
			return map[string]interface{}{"id": t.ID, "content": t.Content, "status": fmt.Sprint(t.Status)}, nil
		},
	},
}

// filterSearchForScopes drops the parts of a search result the key may not read.
func filterSearchForScopes(result interface{}, scopes []string) interface{} {
	m, ok := result.(map[string]interface{})
	if !ok {
		return result
	}
	has := map[string]bool{}
	for _, sc := range scopes {
		has[sc] = true
	}
	if !has[storage.ScopeTasksRead] {
		m["tasks"] = []taskView{}
	}
	if !has[storage.ScopeListsRead] {
		m["listItems"] = []domain.ListItem{}
	}
	return m
}