package config

import (
	"os"
	"testing"

	"ai-agent-scaffold-go/internal/model"
	"github.com/stretchr/testify/assert"
)

// ============================================================
// 辅助函数
// ============================================================

func newTestTable() model.AiAgentConfigTable {
	return model.AiAgentConfigTable{
		AppName: "test-app",
		Agent:   model.AgentSummary{AgentID: "10001", AgentName: "test", AgentDesc: "test agent"},
		Module: model.AgentModule{
			AiAPI:     model.AiAPIConfig{BaseURL: "http://localhost:8080", APIKey: "test-key"},
			ChatModel: model.ChatModelConfig{Model: "gpt-4"},
			Agents:    []model.AgentConfig{{Name: "bot", Instruction: "hello"}},
			Runner:    model.RunnerConfig{AgentName: "bot"},
		},
	}
}

func newTestYAML() []byte {
	return []byte(`
ai:
  agent:
    config:
      tables:
        test-app:
          app-name: test-app
          agent:
            agent-id: "10001"
            agent-name: test
            agent-desc: test agent
          module:
            ai-api:
              base-url: "http://localhost:8080"
              api-key: "test-key"
            chat-model:
              model: "gpt-4"
            agents:
              - name: bot
                instruction: hello
            runner:
              agent-name: bot
`)
}

// ============================================================
// expandEnvPlaceholders 测试
// ============================================================

func TestExpandEnvPlaceholders_SetVar_ReturnsValue(t *testing.T) {
	t.Setenv("TEST_URL", "http://example.com")
	result := expandEnvPlaceholders("url=${TEST_URL}")
	assert.Equal(t, "url=http://example.com", result)
}

func TestExpandEnvPlaceholders_UnsetVar_NoDefault_ReturnsEmpty(t *testing.T) {
	os.Unsetenv("TEST_MISSING_VAR")
	result := expandEnvPlaceholders("url=${TEST_MISSING_VAR}")
	assert.Equal(t, "url=", result)
}

func TestExpandEnvPlaceholders_UnsetVar_WithDefault_ReturnsDefault(t *testing.T) {
	os.Unsetenv("TEST_DEFAULT_VAR")
	result := expandEnvPlaceholders("url=${TEST_DEFAULT_VAR:-http://localhost}")
	assert.Equal(t, "url=http://localhost", result)
}

func TestExpandEnvPlaceholders_SetVar_IgnoresDefault(t *testing.T) {
	t.Setenv("TEST_OVERRIDE", "http://real.com")
	result := expandEnvPlaceholders("url=${TEST_OVERRIDE:-http://default.com}")
	assert.Equal(t, "url=http://real.com", result)
}

func TestExpandEnvPlaceholders_MultipleVars(t *testing.T) {
	t.Setenv("VAR_A", "aaa")
	t.Setenv("VAR_B", "bbb")
	result := expandEnvPlaceholders("${VAR_A}-${VAR_B}")
	assert.Equal(t, "aaa-bbb", result)
}

// ============================================================
// validateTable 测试 — table-driven
// ============================================================

func TestValidateTable(t *testing.T) {
	tests := []struct {
		name    string
		modify  func(*model.AiAgentConfigTable)
		wantErr string
	}{
		{"missing app-name", func(t *model.AiAgentConfigTable) { t.AppName = "" }, "app-name"},
		{"missing agent-id", func(t *model.AiAgentConfigTable) { t.Agent.AgentID = "" }, "agent.agent-id"},
		{"missing base-url", func(t *model.AiAgentConfigTable) { t.Module.AiAPI.BaseURL = "" }, "module.ai-api.base-url"},
		{"missing api-key", func(t *model.AiAgentConfigTable) { t.Module.AiAPI.APIKey = "" }, "module.ai-api.api-key"},
		{"missing model", func(t *model.AiAgentConfigTable) { t.Module.ChatModel.Model = "" }, "module.chat-model.model"},
		{"missing runner agent-name", func(t *model.AiAgentConfigTable) { t.Module.Runner.AgentName = "" }, "module.runner.agent-name"},
		{"missing agents", func(t *model.AiAgentConfigTable) { t.Module.Agents = nil }, "module.agents"},
		{"empty agent name", func(t *model.AiAgentConfigTable) { t.Module.Agents[0].Name = "" }, "module.agents[0].name"},
		{"empty agent instruction", func(t *model.AiAgentConfigTable) { t.Module.Agents[0].Instruction = "" }, "module.agents[0].instruction"},
		{"invalid workflow type", func(t *model.AiAgentConfigTable) {
			t.Module.AgentWorkflows = []model.AgentWorkflowConfig{
				{Type: "bad", Name: "wf"},
			}
		}, "module.agent-workflows[0].type is invalid"},
		{"missing workflow name", func(t *model.AiAgentConfigTable) {
			t.Module.AgentWorkflows = []model.AgentWorkflowConfig{
				{Type: model.WorkflowTypeSequential, Name: ""},
			}
		}, "module.agent-workflows[0].name is required"},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			table := newTestTable()
			tt.modify(&table)
			err := validateTable("test", table)
			assert.Error(t, err)
			assert.Contains(t, err.Error(), tt.wantErr)
		})
	}
}

func TestValidateTable_ValidTable_NoError(t *testing.T) {
	table := newTestTable()
	err := validateTable("test", table)
	assert.NoError(t, err)
}

// ============================================================
// normalizeDefaults 测试
// ============================================================

func TestNormalizeDefaults_SetsCompletionsPath(t *testing.T) {
	table := newTestTable()
	table.Module.AiAPI.CompletionsPath = ""
	normalizeDefaults(&table)
	assert.Equal(t, "v1/chat/completions", table.Module.AiAPI.CompletionsPath)
}

func TestNormalizeDefaults_SetsMaxIterations(t *testing.T) {
	table := newTestTable()
	table.Module.AgentWorkflows = []model.AgentWorkflowConfig{
		{Type: model.WorkflowTypeLoop, Name: "loop", MaxIterations: 0},
	}
	normalizeDefaults(&table)
	assert.Equal(t, 3, table.Module.AgentWorkflows[0].MaxIterations)
}

// ============================================================
// LoadAgentTables 测试
// ============================================================

func TestLoadAgentTables_ValidYAML_ReturnsTable(t *testing.T) {
	tables, err := LoadAgentTables(newTestYAML())
	assert.NoError(t, err)
	assert.Len(t, tables, 1)

	table, ok := tables["test-app"]
	assert.True(t, ok)
	assert.Equal(t, "test-app", table.AppName)
	assert.Equal(t, "10001", table.Agent.AgentID)
	assert.Equal(t, "gpt-4", table.Module.ChatModel.Model)
}

func TestLoadAgentTables_WithEnvVar_Substitutes(t *testing.T) {
	t.Setenv("TEST_LLM_URL", "http://llm.example.com")
	yaml := []byte(`
ai:
  agent:
    config:
      tables:
        t:
          app-name: app
          agent:
            agent-id: "1"
            agent-name: n
            agent-desc: d
          module:
            ai-api:
              base-url: "${TEST_LLM_URL}"
              api-key: k
            chat-model:
              model: m
            agents:
              - name: bot
                instruction: hi
            runner:
              agent-name: bot
`)
	tables, err := LoadAgentTables(yaml)
	assert.NoError(t, err)
	assert.Equal(t, "http://llm.example.com", tables["t"].Module.AiAPI.BaseURL)
}

func TestLoadAgentTables_EmptyTables_ReturnsError(t *testing.T) {
	yaml := []byte(`
ai:
  agent:
    config:
      tables: {}
`)
	_, err := LoadAgentTables(yaml)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "agent config tables are required")
}

func TestLoadAgentTables_InvalidYAML_ReturnsError(t *testing.T) {
	_, err := LoadAgentTables([]byte("not: [valid: yaml"))
	assert.Error(t, err)
}

func TestLoadAgentTables_MissingRequiredField_ReturnsError(t *testing.T) {
	yaml := []byte(`
ai:
  agent:
    config:
      tables:
        t:
          app-name: ""
          agent:
            agent-id: "1"
          module:
            ai-api:
              base-url: u
              api-key: k
            chat-model:
              model: m
            agents:
              - name: bot
                instruction: hi
            runner:
              agent-name: bot
`)
	_, err := LoadAgentTables(yaml)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "app-name")
}

// ============================================================
// LoadAgentTablesFile 测试
// ============================================================

func TestLoadAgentTablesFile_ValidFile_ReturnsTable(t *testing.T) {
	tmp, err := os.CreateTemp("", "agent-*.yaml")
	assert.NoError(t, err)
	defer os.Remove(tmp.Name())

	_, err = tmp.Write(newTestYAML())
	assert.NoError(t, err)
	tmp.Close()

	tables, err := LoadAgentTablesFile(tmp.Name())
	assert.NoError(t, err)
	assert.Len(t, tables, 1)
}

func TestLoadAgentTablesFile_FileNotFound_ReturnsError(t *testing.T) {
	_, err := LoadAgentTablesFile("/nonexistent/path.yaml")
	assert.Error(t, err)
}