package handler

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"

	middleware2 "github.com/Wei-Shaw/sub2api/internal/server/middleware"
	"github.com/Wei-Shaw/sub2api/internal/service"
	"github.com/gin-gonic/gin"
	"github.com/stretchr/testify/require"
)

type gatewayModelsAccountRepoStub struct {
	service.AccountRepository

	byGroup map[int64][]service.Account
}

type gatewayModelsResponseForTest struct {
	Object string                    `json:"object"`
	Data   []gatewayModelItemForTest `json:"data"`
}

type gatewayModelItemForTest struct {
	ID        string `json:"id"`
	Object    string `json:"object"`
	Created   int64  `json:"created"`
	OwnedBy   string `json:"owned_by"`
	CreatedAt string `json:"created_at"`
}

func (s *gatewayModelsAccountRepoStub) ListSchedulableByGroupID(ctx context.Context, groupID int64) ([]service.Account, error) {
	accounts, ok := s.byGroup[groupID]
	if !ok {
		return nil, nil
	}
	out := make([]service.Account, len(accounts))
	copy(out, accounts)
	return out, nil
}

func newGatewayModelsHandlerForTest(repo service.AccountRepository) *GatewayHandler {
	return &GatewayHandler{
		gatewayService: service.NewGatewayService(
			repo,
			nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil,
			nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil,
		),
	}
}

func TestGatewayModels_GeminiGroupFallsBackToGeminiModels(t *testing.T) {
	gin.SetMode(gin.TestMode)

	groupID := int64(20)
	h := newGatewayModelsHandlerForTest(
		&gatewayModelsAccountRepoStub{
			byGroup: map[int64][]service.Account{
				groupID: {
					{ID: 1, Platform: service.PlatformGemini},
				},
			},
		},
	)

	rec := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(rec)
	c.Request = httptest.NewRequest(http.MethodGet, "/v1/models", nil)
	c.Set(string(middleware2.ContextKeyAPIKey), &service.APIKey{
		Group: &service.Group{ID: groupID, Platform: service.PlatformGemini},
	})

	h.Models(c)

	require.Equal(t, http.StatusOK, rec.Code)

	var got gatewayModelsResponseForTest
	require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &got))
	require.Equal(t, "list", got.Object)
	require.Contains(t, modelIDsForTest(got.Data), "gemini-2.5-flash")
	require.NotContains(t, modelIDsForTest(got.Data), "claude-sonnet-4-6")
}

func TestGatewayModels_GeminiGroupFiltersMappedModelsByPlatform(t *testing.T) {
	gin.SetMode(gin.TestMode)

	groupID := int64(21)
	h := newGatewayModelsHandlerForTest(
		&gatewayModelsAccountRepoStub{
			byGroup: map[int64][]service.Account{
				groupID: {
					{
						ID:       1,
						Platform: service.PlatformAnthropic,
						Credentials: map[string]any{
							"model_mapping": map[string]any{
								"claude-sonnet-4-6": "claude-sonnet-4-6",
							},
						},
					},
					{
						ID:       2,
						Platform: service.PlatformGemini,
						Credentials: map[string]any{
							"model_mapping": map[string]any{
								"gemini-2.5-flash": "gemini-2.5-flash",
							},
						},
					},
				},
			},
		},
	)

	rec := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(rec)
	c.Request = httptest.NewRequest(http.MethodGet, "/v1/models", nil)
	c.Set(string(middleware2.ContextKeyAPIKey), &service.APIKey{
		Group: &service.Group{ID: groupID, Platform: service.PlatformGemini},
	})

	h.Models(c)

	require.Equal(t, http.StatusOK, rec.Code)

	var got gatewayModelsResponseForTest
	require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &got))
	require.Equal(t, []string{"gemini-2.5-flash"}, modelIDsForTest(got.Data))
}

func TestGatewayModels_CustomModelsListDisabledKeepsOriginalModels(t *testing.T) {
	gin.SetMode(gin.TestMode)

	groupID := int64(22)
	h := newGatewayModelsHandlerForTest(
		&gatewayModelsAccountRepoStub{
			byGroup: map[int64][]service.Account{
				groupID: {
					{
						ID:       1,
						Platform: service.PlatformOpenAI,
						Credentials: map[string]any{
							"model_mapping": map[string]any{
								"gpt-5.5": "gpt-5.5",
								"gpt-5.4": "gpt-5.4",
							},
						},
					},
				},
			},
		},
	)

	rec := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(rec)
	c.Request = httptest.NewRequest(http.MethodGet, "/v1/models", nil)
	c.Set(string(middleware2.ContextKeyAPIKey), &service.APIKey{
		Group: &service.Group{
			ID:       groupID,
			Platform: service.PlatformOpenAI,
			ModelsListConfig: service.GroupModelsListConfig{
				Enabled: false,
				Models:  []string{"gpt-5.5"},
			},
		},
	})

	h.Models(c)

	require.Equal(t, http.StatusOK, rec.Code)

	var got gatewayModelsResponseForTest
	require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &got))
	require.Equal(t, []string{"gpt-5.4", "gpt-5.5"}, modelIDsForTest(got.Data))
}

func TestGatewayModels_CustomModelsListFiltersAndOrdersMappedModels(t *testing.T) {
	gin.SetMode(gin.TestMode)

	groupID := int64(23)
	h := newGatewayModelsHandlerForTest(
		&gatewayModelsAccountRepoStub{
			byGroup: map[int64][]service.Account{
				groupID: {
					{
						ID:       1,
						Platform: service.PlatformOpenAI,
						Credentials: map[string]any{
							"model_mapping": map[string]any{
								"gpt-5.4":         "gpt-5.4",
								"gpt-5.5":         "gpt-5.5",
								"legacy-gpt-2024": "legacy-gpt-2024",
							},
						},
					},
				},
			},
		},
	)

	rec := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(rec)
	c.Request = httptest.NewRequest(http.MethodGet, "/v1/models", nil)
	c.Set(string(middleware2.ContextKeyAPIKey), &service.APIKey{
		Group: &service.Group{
			ID:       groupID,
			Platform: service.PlatformOpenAI,
			ModelsListConfig: service.GroupModelsListConfig{
				Enabled: true,
				Models:  []string{"gpt-5.5", "missing-model", "gpt-5.4"},
			},
		},
	})

	h.Models(c)

	require.Equal(t, http.StatusOK, rec.Code)

	var got gatewayModelsResponseForTest
	require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &got))
	require.Equal(t, []string{"gpt-5.5", "gpt-5.4"}, modelIDsForTest(got.Data))
}

func TestGatewayModels_CustomModelsListKeepsConcreteModelAllowedByWildcardMapping(t *testing.T) {
	gin.SetMode(gin.TestMode)

	groupID := int64(26)
	h := newGatewayModelsHandlerForTest(
		&gatewayModelsAccountRepoStub{
			byGroup: map[int64][]service.Account{
				groupID: {
					{
						ID:       1,
						Platform: service.PlatformAnthropic,
						Credentials: map[string]any{
							"model_mapping": map[string]any{
								"claude-*": "claude-sonnet-4-6",
							},
						},
					},
				},
			},
		},
	)

	rec := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(rec)
	c.Request = httptest.NewRequest(http.MethodGet, "/v1/models", nil)
	c.Set(string(middleware2.ContextKeyAPIKey), &service.APIKey{
		Group: &service.Group{
			ID:       groupID,
			Platform: service.PlatformAnthropic,
			ModelsListConfig: service.GroupModelsListConfig{
				Enabled: true,
				Models:  []string{"claude-sonnet-4-6"},
			},
		},
	})

	h.Models(c)

	require.Equal(t, http.StatusOK, rec.Code)

	var got gatewayModelsResponseForTest
	require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &got))
	require.Equal(t, []string{"claude-sonnet-4-6"}, modelIDsForTest(got.Data))
}

func TestGatewayModels_CustomModelsListCanReturnEmptyWhenSelectionsUnavailable(t *testing.T) {
	gin.SetMode(gin.TestMode)

	groupID := int64(24)
	h := newGatewayModelsHandlerForTest(
		&gatewayModelsAccountRepoStub{
			byGroup: map[int64][]service.Account{
				groupID: {
					{
						ID:       1,
						Platform: service.PlatformOpenAI,
						Credentials: map[string]any{
							"model_mapping": map[string]any{
								"gpt-5.4": "gpt-5.4",
							},
						},
					},
				},
			},
		},
	)

	rec := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(rec)
	c.Request = httptest.NewRequest(http.MethodGet, "/v1/models", nil)
	c.Set(string(middleware2.ContextKeyAPIKey), &service.APIKey{
		Group: &service.Group{
			ID:       groupID,
			Platform: service.PlatformOpenAI,
			ModelsListConfig: service.GroupModelsListConfig{
				Enabled: true,
				Models:  []string{"gpt-5.5"},
			},
		},
	})

	h.Models(c)

	require.Equal(t, http.StatusOK, rec.Code)

	var got gatewayModelsResponseForTest
	require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &got))
	require.Empty(t, modelIDsForTest(got.Data))
}

func TestGatewayModels_CustomModelsListFiltersDefaultFallbackModels(t *testing.T) {
	gin.SetMode(gin.TestMode)

	groupID := int64(25)
	h := newGatewayModelsHandlerForTest(
		&gatewayModelsAccountRepoStub{
			byGroup: map[int64][]service.Account{
				groupID: {
					{ID: 1, Platform: service.PlatformOpenAI},
				},
			},
		},
	)

	rec := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(rec)
	c.Request = httptest.NewRequest(http.MethodGet, "/v1/models", nil)
	c.Set(string(middleware2.ContextKeyAPIKey), &service.APIKey{
		Group: &service.Group{
			ID:       groupID,
			Platform: service.PlatformOpenAI,
			ModelsListConfig: service.GroupModelsListConfig{
				Enabled: true,
				Models:  []string{"gpt-5.5", "legacy-gpt-2024", "gpt-5.4"},
			},
		},
	})

	h.Models(c)

	require.Equal(t, http.StatusOK, rec.Code)

	var got gatewayModelsResponseForTest
	require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &got))
	require.Equal(t, []string{"gpt-5.5", "gpt-5.4"}, modelIDsForTest(got.Data))
}

func TestGatewayModels_OpenAICustomModelsListKeepsOpenAIResponseShapeForDefaultFallback(t *testing.T) {
	gin.SetMode(gin.TestMode)

	groupID := int64(27)
	h := newGatewayModelsHandlerForTest(
		&gatewayModelsAccountRepoStub{
			byGroup: map[int64][]service.Account{
				groupID: {
					{ID: 1, Platform: service.PlatformOpenAI},
				},
			},
		},
	)

	rec := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(rec)
	c.Request = httptest.NewRequest(http.MethodGet, "/v1/models", nil)
	c.Set(string(middleware2.ContextKeyAPIKey), &service.APIKey{
		Group: &service.Group{
			ID:       groupID,
			Platform: service.PlatformOpenAI,
			ModelsListConfig: service.GroupModelsListConfig{
				Enabled: true,
				Models:  []string{"gpt-5.5", "gpt-5.4"},
			},
		},
	})

	h.Models(c)

	require.Equal(t, http.StatusOK, rec.Code)

	var got gatewayModelsResponseForTest
	require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &got))
	require.Equal(t, []string{"gpt-5.5", "gpt-5.4"}, modelIDsForTest(got.Data))
	require.Equal(t, "model", got.Data[0].Object)
	require.NotZero(t, got.Data[0].Created)
	require.Equal(t, "openai", got.Data[0].OwnedBy)
	require.Empty(t, got.Data[0].CreatedAt)
}

func modelIDsForTest(models []gatewayModelItemForTest) []string {
	ids := make([]string, 0, len(models))
	for _, model := range models {
		ids = append(ids, model.ID)
	}
	return ids
}