// config_test.go -- 配置系统的单元测试.
//
// 覆盖场景:
//   - defaultSettings 默认值
//   - mergeSettings 多级合并
//   - loadSettingsFile 从文件加载
//   - SaveSettings 保存配置
//   - LoadSettings 完整加载流程
package config

import (
	"encoding/json"
	"os"
	"path/filepath"
	"testing"
)

// TestDefaultSettings 测试默认设置
func TestDefaultSettings(t *testing.T) {
	s := defaultSettings()
	if s.Permissions.DefaultMode != "default" {
		t.Errorf("默认模式应为 'default', 实际: %q", s.Permissions.DefaultMode)
	}
	if s.MCPServers == nil {
		t.Error("MCPServers 不应为 nil")
	}
	if s.Hooks == nil {
		t.Error("Hooks 不应为 nil")
	}
}

// TestMergeSettings 测试设置合并
func TestMergeSettings(t *testing.T) {
	dst := defaultSettings()
	src := &Settings{
		Model:              "claude-sonnet-4-6",
		MaxTurns:           100,
		CustomInstructions: "custom",
		Verbose:            true,
		Permissions: PermissionSettings{
			AllowedTools: []string{"Bash(prefix:npm)"},
			DefaultMode:  "accept_edits",
		},
	}

	mergeSettings(dst, src)

	if dst.Model != "claude-sonnet-4-6" {
		t.Errorf("Model: %q", dst.Model)
	}
	if dst.MaxTurns != 100 {
		t.Errorf("MaxTurns: %d", dst.MaxTurns)
	}
	if dst.CustomInstructions != "custom" {
		t.Errorf("CustomInstructions: %q", dst.CustomInstructions)
	}
	if !dst.Verbose {
		t.Error("Verbose 应为 true")
	}
	if dst.Permissions.DefaultMode != "accept_edits" {
		t.Errorf("DefaultMode: %q", dst.Permissions.DefaultMode)
	}
	if len(dst.Permissions.AllowedTools) != 1 {
		t.Errorf("AllowedTools 数量: %d", len(dst.Permissions.AllowedTools))
	}
}

// TestMergeSettings_ZeroValues 测试零值不覆盖
func TestMergeSettings_ZeroValues(t *testing.T) {
	dst := &Settings{
		Model:    "claude-opus-4-6",
		MaxTurns: 50,
	}
	src := &Settings{
		// 零值不应覆盖
	}

	mergeSettings(dst, src)

	if dst.Model != "claude-opus-4-6" {
		t.Errorf("零值不应覆盖 Model: %q", dst.Model)
	}
	if dst.MaxTurns != 50 {
		t.Errorf("零值不应覆盖 MaxTurns: %d", dst.MaxTurns)
	}
}

// TestMergeSettings_MCPServers 测试 MCP 服务器合并
func TestMergeSettings_MCPServers(t *testing.T) {
	dst := defaultSettings()
	dst.MCPServers["server1"] = MCPServerConfig{Name: "s1", Transport: "stdio"}

	src := &Settings{
		MCPServers: map[string]MCPServerConfig{
			"server2": {Name: "s2", Transport: "sse"},
		},
	}

	mergeSettings(dst, src)

	if len(dst.MCPServers) != 2 {
		t.Errorf("合并后应有 2 个服务器, 实际 %d", len(dst.MCPServers))
	}
}

// TestLoadSettingsFile 测试从文件加载设置
func TestLoadSettingsFile(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "settings.json")

	settings := &Settings{
		Model:    "claude-haiku-4-5",
		MaxTurns: 200,
	}
	data, _ := json.MarshalIndent(settings, "", "  ")
	os.WriteFile(path, data, 0644)

	loaded, err := loadSettingsFile(path)
	if err != nil {
		t.Fatalf("加载失败: %v", err)
	}
	if loaded.Model != "claude-haiku-4-5" {
		t.Errorf("Model: %q", loaded.Model)
	}
	if loaded.MaxTurns != 200 {
		t.Errorf("MaxTurns: %d", loaded.MaxTurns)
	}
}

// TestLoadSettingsFile_NotExist 测试文件不存在
func TestLoadSettingsFile_NotExist(t *testing.T) {
	_, err := loadSettingsFile("/nonexistent/settings.json")
	if err == nil {
		t.Error("文件不存在应报错")
	}
}

// TestLoadSettingsFile_InvalidJSON 测试无效 JSON
func TestLoadSettingsFile_InvalidJSON(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "bad.json")
	os.WriteFile(path, []byte("{invalid json"), 0644)

	_, err := loadSettingsFile(path)
	if err == nil {
		t.Error("无效 JSON 应报错")
	}
}

// TestSaveSettings 测试保存设置
func TestSaveSettings(t *testing.T) {
	dir := t.TempDir()
	settings := &Settings{Model: "claude-sonnet-4-6", MaxTurns: 100}

	err := SaveSettings(ScopeProject, dir, settings)
	if err != nil {
		t.Fatalf("保存失败: %v", err)
	}

	// 验证文件存在
	path := filepath.Join(dir, ".flyto", "settings.json")
	if _, err := os.Stat(path); os.IsNotExist(err) {
		t.Fatal("配置文件应存在")
	}

	// 验证内容可加载
	loaded, err := loadSettingsFile(path)
	if err != nil {
		t.Fatalf("加载失败: %v", err)
	}
	if loaded.Model != "claude-sonnet-4-6" {
		t.Errorf("Model: %q", loaded.Model)
	}
}

// TestSaveSettings_DefaultScope 测试保存到 default scope 不执行
func TestSaveSettings_DefaultScope(t *testing.T) {
	err := SaveSettings(ScopeDefault, "/tmp", &Settings{})
	if err != nil {
		t.Errorf("default scope 不应报错: %v", err)
	}
}

// TestLoadSettings_MultiLevel 测试多级设置加载
func TestLoadSettings_MultiLevel(t *testing.T) {
	dir := t.TempDir()

	// 创建项目级配置
	projectDir := filepath.Join(dir, ".flyto")
	os.MkdirAll(projectDir, 0755)

	projectSettings := &Settings{
		Model:    "claude-sonnet-4-6",
		MaxTurns: 100,
	}
	data, _ := json.MarshalIndent(projectSettings, "", "  ")
	os.WriteFile(filepath.Join(projectDir, "settings.json"), data, 0644)

	// 创建本地级配置(覆盖部分值)
	localSettings := &Settings{
		MaxTurns: 200,
		Verbose:  true,
	}
	data, _ = json.MarshalIndent(localSettings, "", "  ")
	os.WriteFile(filepath.Join(projectDir, "settings.local.json"), data, 0644)

	settings, err := LoadSettings(dir)
	if err != nil {
		t.Fatalf("加载失败: %v", err)
	}

	// Model 来自项目级
	if settings.Model != "claude-sonnet-4-6" {
		t.Errorf("Model 应来自项目级: %q", settings.Model)
	}
	// MaxTurns 来自本地级(覆盖项目级)
	if settings.MaxTurns != 200 {
		t.Errorf("MaxTurns 应被本地级覆盖: %d", settings.MaxTurns)
	}
	// Verbose 来自本地级
	if !settings.Verbose {
		t.Error("Verbose 应来自本地级")
	}
}