// PicoClaw - Ultra-lightweight personal AI agent
// Inspired by and based on nanobot: https://github.com/HKUDS/nanobot
// License: MIT
//
// Copyright (c) 2026 PicoClaw contributors

package agent

import (
	"context"
	"errors"
	"strings"
	"testing"

	"github.com/sipeed/picoclaw/pkg/config"
	"github.com/sipeed/picoclaw/pkg/mcp"
)

func boolPtr(b bool) *bool { return &b }

func TestMCPRuntimeResetClearsState(t *testing.T) {
	var rt mcpRuntime
	manager := mcp.NewManager()
	rt.setManager(manager)
	rt.setInitErr(errors.New("stale init error"))
	rt.initOnce.Do(func() {})

	got := rt.reset()
	if got != manager {
		t.Fatalf("reset() manager = %p, want %p", got, manager)
	}
	if rt.hasManager() {
		t.Fatal("expected manager to be cleared after reset")
	}
	if err := rt.getInitErr(); err != nil {
		t.Fatalf("getInitErr() = %v, want nil", err)
	}

	reran := false
	rt.initOnce.Do(func() { reran = true })
	if !reran {
		t.Fatal("expected initOnce to be reset")
	}
}

func TestReloadProviderAndConfig_ResetsMCPRuntime(t *testing.T) {
	al, cfg, _, _, cleanup := newTestAgentLoop(t)
	defer cleanup()
	defer al.Close()

	manager := mcp.NewManager()
	al.mcp.setManager(manager)
	al.mcp.setInitErr(errors.New("stale init error"))
	al.mcp.initOnce.Do(func() {})

	if !al.mcp.hasManager() {
		t.Fatal("expected MCP manager to exist before reload")
	}

	if err := al.ReloadProviderAndConfig(context.Background(), &mockProvider{}, cfg); err != nil {
		t.Fatalf("ReloadProviderAndConfig() error = %v", err)
	}

	if al.mcp.hasManager() {
		t.Fatal("expected MCP manager to be cleared when reloaded config has MCP disabled")
	}
	if err := al.mcp.getInitErr(); err != nil {
		t.Fatalf("getInitErr() = %v, want nil", err)
	}

	reran := false
	al.mcp.initOnce.Do(func() { reran = true })
	if !reran {
		t.Fatal("expected MCP initOnce to be reset after reload")
	}
}

func TestServerIsDeferred(t *testing.T) {
	tests := []struct {
		name             string
		discoveryEnabled bool
		serverDeferred   *bool
		want             bool
	}{
		// --- global false always wins: per-server deferred is ignored ---
		{
			name:             "global false: per-server deferred=true is ignored",
			discoveryEnabled: false,
			serverDeferred:   boolPtr(true),
			want:             false,
		},
		{
			name:             "global false: per-server deferred=false stays false",
			discoveryEnabled: false,
			serverDeferred:   boolPtr(false),
			want:             false,
		},
		// --- global true: per-server override applies ---
		{
			name:             "global true: per-server deferred=false opts out",
			discoveryEnabled: true,
			serverDeferred:   boolPtr(false),
			want:             false,
		},
		{
			name:             "global true: per-server deferred=true stays true",
			discoveryEnabled: true,
			serverDeferred:   boolPtr(true),
			want:             true,
		},
		// --- no per-server override: fall back to global ---
		{
			name:             "no per-server field, global discovery enabled",
			discoveryEnabled: true,
			serverDeferred:   nil,
			want:             true,
		},
		{
			name:             "no per-server field, global discovery disabled",
			discoveryEnabled: false,
			serverDeferred:   nil,
			want:             false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			serverCfg := config.MCPServerConfig{Deferred: tt.serverDeferred}
			got := serverIsDeferred(tt.discoveryEnabled, serverCfg)
			if got != tt.want {
				t.Errorf("serverIsDeferred(discoveryEnabled=%v, deferred=%v) = %v, want %v",
					tt.discoveryEnabled, tt.serverDeferred, got, tt.want)
			}
		})
	}
}

func TestEnsureMCPInitialized_LoadFailureSetsInitErr(t *testing.T) {
	al, cfg, _, _, cleanup := newTestAgentLoop(t)
	defer cleanup()
	defer al.Close()

	cfg.Tools = config.ToolsConfig{
		MCP: config.MCPConfig{
			ToolConfig: config.ToolConfig{Enabled: true},
			Servers: map[string]config.MCPServerConfig{
				"broken": {
					Enabled: true,
					Command: "picoclaw-command-that-does-not-exist-for-mcp-tests",
				},
			},
		},
	}

	err := al.ensureMCPInitialized(context.Background())
	if err == nil {
		t.Fatal("ensureMCPInitialized() error = nil, want load failure")
	}
	if !strings.Contains(err.Error(), "failed to load MCP servers") {
		t.Fatalf("ensureMCPInitialized() error = %q, want wrapped load failure", err.Error())
	}

	initErr := al.mcp.getInitErr()
	if initErr == nil {
		t.Fatal("getInitErr() = nil, want cached load failure")
	}
	if !strings.Contains(initErr.Error(), "failed to load MCP servers") {
		t.Fatalf("getInitErr() = %q, want wrapped load failure", initErr.Error())
	}
	if al.mcp.getManager() != nil {
		t.Fatal("expected MCP manager to remain nil after load failure")
	}

	err = al.ensureMCPInitialized(context.Background())
	if err == nil {
		t.Fatal("second ensureMCPInitialized() error = nil, want cached load failure")
	}
	if !strings.Contains(err.Error(), "failed to load MCP servers") {
		t.Fatalf("second ensureMCPInitialized() error = %q, want wrapped load failure", err.Error())
	}
}