package api

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

	"github.com/gin-gonic/gin"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"visiona-backend/internal/model"
	"visiona-backend/internal/storage"
)

// 建一個 in-memory fixture（storage + model repo）給 models_test 用。
func newModelsFixture(t *testing.T) (*gin.Engine, *model.InMemoryRepository, *storage.LocalFSStore) {
	t.Helper()

	dir := t.TempDir()
	st, err := storage.NewLocalFSStore(dir, "http://api/storage", "test-secret")
	require.NoError(t, err)

	repo := model.NewInMemoryRepository()

	r := gin.New()
	r.Use(RequestIDMiddleware())
	// Phase 0.7 security fix C1：injectStaticUserContext 顯式注入 UserContext。
	r.Use(injectStaticUserContext("demo-user", ""))
	g := r.Group("/api")
	registerModelRoutes(g, Deps{
		ModelRepo:       repo,
		Storage:         st,
		MaxUploadSizeMB: 10,
	})
	return r, repo, st
}

// TestModelsInit_OK 驗證 init 能成功：建立 pending 紀錄並回 upload_url。
func TestModelsInit_OK(t *testing.T) {
	r, repo, _ := newModelsFixture(t)

	body := strings.NewReader(`{"name":"m1","file_size":1024}`)
	w := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodPost, "/api/models/init", body)
	req.Header.Set("Content-Type", "application/json")
	r.ServeHTTP(w, req)

	require.Equal(t, http.StatusOK, w.Code, "body=%s", w.Body.String())

	var sb SuccessBody
	require.NoError(t, json.Unmarshal(w.Body.Bytes(), &sb))
	data := sb.Data.(map[string]any)

	modelID, _ := data["model_id"].(string)
	require.NotEmpty(t, modelID)
	assert.Contains(t, data["upload_url"].(string), "signature=")

	// Repo 中應已有 pending 紀錄（UploadedAt == nil）
	m, err := repo.Get(context.Background(), modelID)
	require.NoError(t, err)
	assert.Nil(t, m.UploadedAt)
	assert.Equal(t, int64(1024), m.FileSize)
}

// TestModelsInit_NameMissing 驗證沒 name 回 400。
func TestModelsInit_NameMissing(t *testing.T) {
	r, _, _ := newModelsFixture(t)

	body := strings.NewReader(`{"file_size":1024}`)
	w := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodPost, "/api/models/init", body)
	req.Header.Set("Content-Type", "application/json")
	r.ServeHTTP(w, req)

	assert.Equal(t, http.StatusBadRequest, w.Code)
	assert.Contains(t, w.Body.String(), ErrCodeValidationFailed)
}

// TestModelsInit_TooLarge 驗證超過限制回 413。
func TestModelsInit_TooLarge(t *testing.T) {
	r, _, _ := newModelsFixture(t)
	// MaxUploadSizeMB=10，送 11MB
	body := strings.NewReader(`{"name":"big","file_size":11534336}`) // 11 MB
	w := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodPost, "/api/models/init", body)
	req.Header.Set("Content-Type", "application/json")
	r.ServeHTTP(w, req)

	assert.Equal(t, http.StatusRequestEntityTooLarge, w.Code)
	assert.Contains(t, w.Body.String(), ErrCodePayloadTooLarge)
}

// TestModelsFinalize_FileNotUploaded 驗證 finalize 在沒實際 PUT 前回 400。
func TestModelsFinalize_FileNotUploaded(t *testing.T) {
	r, repo, _ := newModelsFixture(t)

	// 先塞一筆 pending model（沒實際檔案）
	now := time.Now().UTC()
	m := &model.Model{
		ID:          "mdl-1",
		OwnerUserID: "demo-user",
		Name:        "x",
		FileSize:    100,
		StorageKey:  "models/demo-user/mdl-1.nef",
		Source:      model.SourceUploaded,
		CreatedAt:   now,
	}
	require.NoError(t, repo.Save(context.Background(), m))

	w := httptest.NewRecorder()
	r.ServeHTTP(w, httptest.NewRequest(http.MethodPost, "/api/models/mdl-1/finalize", nil))
	assert.Equal(t, http.StatusBadRequest, w.Code)
	assert.Contains(t, w.Body.String(), "file not uploaded")
}

// TestModelsFinalize_SizeMismatch 驗證實際檔案大小對不上 file_size 回 400。
func TestModelsFinalize_SizeMismatch(t *testing.T) {
	r, repo, st := newModelsFixture(t)

	// 塞 pending model（宣稱 100 bytes）
	require.NoError(t, repo.Save(context.Background(), &model.Model{
		ID:          "mdl-2",
		OwnerUserID: "demo-user",
		Name:        "x",
		FileSize:    100,
		StorageKey:  "models/demo-user/mdl-2.nef",
		Source:      model.SourceUploaded,
	}))
	// 實際檔案寫 10 bytes（Size 不符）
	require.NoError(t, st.Put(context.Background(), "models/demo-user/mdl-2.nef",
		strings.NewReader("0123456789"), 10, nil))

	w := httptest.NewRecorder()
	r.ServeHTTP(w, httptest.NewRequest(http.MethodPost, "/api/models/mdl-2/finalize", nil))
	assert.Equal(t, http.StatusBadRequest, w.Code)
	assert.Contains(t, w.Body.String(), "size mismatch")
}

// TestModelsFinalize_OK 驗證 happy path：檔案已存在、size 對得上，標 ready。
func TestModelsFinalize_OK(t *testing.T) {
	r, repo, st := newModelsFixture(t)

	require.NoError(t, repo.Save(context.Background(), &model.Model{
		ID:          "mdl-3",
		OwnerUserID: "demo-user",
		Name:        "x",
		FileSize:    5,
		StorageKey:  "models/demo-user/mdl-3.nef",
		Source:      model.SourceUploaded,
	}))
	require.NoError(t, st.Put(context.Background(), "models/demo-user/mdl-3.nef",
		strings.NewReader("hello"), 5, nil))

	w := httptest.NewRecorder()
	r.ServeHTTP(w, httptest.NewRequest(http.MethodPost, "/api/models/mdl-3/finalize", nil))
	require.Equal(t, http.StatusOK, w.Code, "body=%s", w.Body.String())

	// Repo 中應已 UploadedAt 被設
	m, err := repo.Get(context.Background(), "mdl-3")
	require.NoError(t, err)
	assert.NotNil(t, m.UploadedAt)
}

// TestModelsDelete_NotOwner 驗證非 owner 不能刪。
func TestModelsDelete_NotOwner(t *testing.T) {
	r, repo, _ := newModelsFixture(t)

	// 塞一個「別人」的 model
	require.NoError(t, repo.Save(context.Background(), &model.Model{
		ID:          "mdl-other",
		OwnerUserID: "other-user",
		Name:        "x",
		Source:      model.SourceUploaded,
	}))

	w := httptest.NewRecorder()
	r.ServeHTTP(w, httptest.NewRequest(http.MethodDelete, "/api/models/mdl-other", nil))
	assert.Equal(t, http.StatusForbidden, w.Code)
}

// TestModelsGet_HTTPResponseCarriesMetadata 驗證 B4 metadata 鏈路的最後序列化點：
// GET /api/models/:id 的 HTTP JSON response 真的含 input_shape / classes / framework。
//
// 這是先前測試的盲區——舊測試只測到 model.Model 落地（dbtest）為止、沒測最外層 HTTP
// JSON。此測試直接 call handler → 解析 response JSON → 斷言三欄都在裡面且值正確。
func TestModelsGet_HTTPResponseCarriesMetadata(t *testing.T) {
	r, repo, _ := newModelsFixture(t)

	now := time.Now().UTC()
	require.NoError(t, repo.Save(context.Background(), &model.Model{
		ID:          "mdl-meta",
		OwnerUserID: "demo-user",
		Name:        "metamodel",
		Source:      model.SourceConverted,
		InputShape:  []int{1, 3, 224, 224},
		Classes:     []string{"cat", "dog"},
		Framework:   "onnx",
		CreatedAt:   now,
		UpdatedAt:   now,
	}))

	w := httptest.NewRecorder()
	r.ServeHTTP(w, httptest.NewRequest(http.MethodGet, "/api/models/mdl-meta", nil))
	require.Equal(t, http.StatusOK, w.Code, "body=%s", w.Body.String())

	var sb SuccessBody
	require.NoError(t, json.Unmarshal(w.Body.Bytes(), &sb))
	data, ok := sb.Data.(map[string]any)
	require.True(t, ok, "data should be an object")

	// input_shape 必須在最外層 HTTP JSON 裡（snake_case，前端 normalize 讀得到）。
	rawShape, present := data["input_shape"]
	require.True(t, present, "input_shape must be present in HTTP JSON response; body=%s", w.Body.String())
	shape, ok := rawShape.([]any)
	require.True(t, ok)
	require.Len(t, shape, 4)
	assert.EqualValues(t, 1, shape[0])
	assert.EqualValues(t, 3, shape[1])
	assert.EqualValues(t, 224, shape[2])
	assert.EqualValues(t, 224, shape[3])

	// classes / framework 同樣要帶到。
	classes, ok := data["classes"].([]any)
	require.True(t, ok, "classes must be present; body=%s", w.Body.String())
	require.Len(t, classes, 2)
	assert.Equal(t, "cat", classes[0])
	assert.Equal(t, "dog", classes[1])

	assert.Equal(t, "onnx", data["framework"])
}

// TestModelsGet_OmitsMetadataWhenAbsent 驗證 omitempty：無 metadata 的 model（如上傳類 /
// 舊 model）回應不含 input_shape / classes / framework，不破壞既有回應結構。
func TestModelsGet_OmitsMetadataWhenAbsent(t *testing.T) {
	r, repo, _ := newModelsFixture(t)

	require.NoError(t, repo.Save(context.Background(), &model.Model{
		ID:          "mdl-nometa",
		OwnerUserID: "demo-user",
		Name:        "plain",
		Source:      model.SourceUploaded,
	}))

	w := httptest.NewRecorder()
	r.ServeHTTP(w, httptest.NewRequest(http.MethodGet, "/api/models/mdl-nometa", nil))
	require.Equal(t, http.StatusOK, w.Code, "body=%s", w.Body.String())

	var sb SuccessBody
	require.NoError(t, json.Unmarshal(w.Body.Bytes(), &sb))
	data, ok := sb.Data.(map[string]any)
	require.True(t, ok)

	_, hasShape := data["input_shape"]
	_, hasClasses := data["classes"]
	_, hasFramework := data["framework"]
	assert.False(t, hasShape, "input_shape should be omitted when empty")
	assert.False(t, hasClasses, "classes should be omitted when empty")
	assert.False(t, hasFramework, "framework should be omitted when empty")
}

// TestModelsList_HTTPResponseCarriesMetadata 驗證 list endpoint（GET /api/models）的
// HTTP JSON 也帶 input_shape（列表頁雖非 B4 主顯示處，仍確認鏈路一致）。
func TestModelsList_HTTPResponseCarriesMetadata(t *testing.T) {
	r, repo, _ := newModelsFixture(t)

	require.NoError(t, repo.Save(context.Background(), &model.Model{
		ID:          "mdl-list-meta",
		OwnerUserID: "demo-user",
		Name:        "listed",
		Source:      model.SourceConverted,
		InputShape:  []int{1, 28, 28},
		Framework:   "tflite",
	}))

	w := httptest.NewRecorder()
	r.ServeHTTP(w, httptest.NewRequest(http.MethodGet, "/api/models", nil))
	require.Equal(t, http.StatusOK, w.Code, "body=%s", w.Body.String())

	var sb SuccessBody
	require.NoError(t, json.Unmarshal(w.Body.Bytes(), &sb))
	arr, ok := sb.Data.([]any)
	require.True(t, ok)
	require.Len(t, arr, 1)
	first := arr[0].(map[string]any)

	rawShape, present := first["input_shape"]
	require.True(t, present, "input_shape must be present in list response; body=%s", w.Body.String())
	shape, ok := rawShape.([]any)
	require.True(t, ok)
	require.Len(t, shape, 3)
	assert.EqualValues(t, 1, shape[0])
	assert.EqualValues(t, 28, shape[1])
	assert.EqualValues(t, 28, shape[2])
	assert.Equal(t, "tflite", first["framework"])
}

// TestModelsList_FiltersByOwner 驗證 list 只回當前 user 的模型。
func TestModelsList_FiltersByOwner(t *testing.T) {
	r, repo, _ := newModelsFixture(t)

	require.NoError(t, repo.Save(context.Background(), &model.Model{
		ID: "my", OwnerUserID: "demo-user", Name: "mine", Source: model.SourceUploaded,
	}))
	require.NoError(t, repo.Save(context.Background(), &model.Model{
		ID: "other", OwnerUserID: "other-user", Name: "theirs", Source: model.SourceUploaded,
	}))

	w := httptest.NewRecorder()
	r.ServeHTTP(w, httptest.NewRequest(http.MethodGet, "/api/models", nil))
	require.Equal(t, http.StatusOK, w.Code)

	var sb SuccessBody
	require.NoError(t, json.Unmarshal(w.Body.Bytes(), &sb))
	arr, ok := sb.Data.([]any)
	require.True(t, ok)
	assert.Len(t, arr, 1, "只應看到自己的 model")
	first := arr[0].(map[string]any)
	assert.Equal(t, "my", first["id"])
}