package files

import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"log"
	"mime/multipart"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/gin-gonic/gin"
	"github.com/glebarez/sqlite"
	"github.com/stretchr/testify/require"
	"gorm.io/gorm"
	"senlinai-agent/backend/internal/config"
	"senlinai-agent/backend/internal/httpx"
	"senlinai-agent/backend/internal/models"
)

func TestFileRegistrarSavesBeforeCreatingIdentitySourceDTO(t *testing.T) {
	router, database, project, storageRoot := newFileHandlerTestRouter(t, 1, 1)
	body := &bytes.Buffer{}
	writer := multipart.NewWriter(body)
	require.NoError(t, writer.WriteField("title", "客户资料"))
	part, err := writer.CreateFormFile("file", "客户资料.txt")
	require.NoError(t, err)
	_, err = part.Write([]byte("private content"))
	require.NoError(t, err)
	require.NoError(t, writer.Close())
	req := httptest.NewRequest(http.MethodPost, "/api/v1/projects/"+project.Identity+"/sources", body)
	req.Header.Set("Content-Type", writer.FormDataContentType())
	req.Header.Set("Authorization", "Bearer test-token")
	rec := httptest.NewRecorder()

	router.ServeHTTP(rec, req)

	require.Equal(t, http.StatusCreated, rec.Code, rec.Body.String())
	var source models.SenlinAgentSource
	require.NoError(t, database.Where("project_id = ?", project.ID).First(&source).Error)
	require.FileExists(t, filepath.Join(storageRoot, filepath.FromSlash(source.FilePath)))
	require.Contains(t, filepath.ToSlash(source.FilePath), "projects/"+project.Identity+"/")
	require.NotContains(t, filepath.ToSlash(source.FilePath), fmt.Sprintf("projects/%d/", project.ID))
	var payload map[string]any
	require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &payload))
	require.Equal(t, source.Identity, payload["id"])
	require.Equal(t, project.Identity, payload["projectId"])
	require.Equal(t, filepath.Base(source.FilePath), payload["storageKey"])
	require.NotContains(t, payload, "filePath")
	require.NotContains(t, payload, "AbsolutePath")
	require.NotContains(t, rec.Body.String(), storageRoot)
	require.NotContains(t, rec.Body.String(), fmt.Sprintf("projects/%d/", project.ID))
}

func TestFileRegistrarChecksOwnershipBeforeWritingFile(t *testing.T) {
	router, database, project, storageRoot := newFileHandlerTestRouter(t, 1, 2)
	body := &bytes.Buffer{}
	writer := multipart.NewWriter(body)
	part, err := writer.CreateFormFile("file", "hidden.txt")
	require.NoError(t, err)
	_, err = part.Write([]byte("must not be stored"))
	require.NoError(t, err)
	require.NoError(t, writer.Close())
	req := httptest.NewRequest(http.MethodPost, "/api/v1/projects/"+project.Identity+"/sources", body)
	req.Header.Set("Content-Type", writer.FormDataContentType())
	req.Header.Set("Authorization", "Bearer test-token")
	rec := httptest.NewRecorder()

	router.ServeHTTP(rec, req)

	require.Equal(t, http.StatusNotFound, rec.Code, rec.Body.String())
	var count int64
	require.NoError(t, database.Model(&models.SenlinAgentSource{}).Count(&count).Error)
	require.Zero(t, count)
	entries, err := os.ReadDir(storageRoot)
	require.NoError(t, err)
	require.Empty(t, entries)
}

func TestFileRegistrarRemovesStoredFileWhenSourceCreateFails(t *testing.T) {
	router, database, project, storageRoot := newFileHandlerTestRouter(t, 1, 1)
	require.NoError(t, database.Callback().Create().Before("gorm:create").Register("test:fail_source_create", func(tx *gorm.DB) {
		if tx.Statement.Schema != nil && tx.Statement.Schema.Table == (models.SenlinAgentSource{}).TableName() {
			tx.AddError(errors.New("forced source create failure"))
		}
	}))
	body := &bytes.Buffer{}
	writer := multipart.NewWriter(body)
	part, err := writer.CreateFormFile("file", "orphan.txt")
	require.NoError(t, err)
	_, err = part.Write([]byte("must be compensated"))
	require.NoError(t, err)
	require.NoError(t, writer.Close())
	req := httptest.NewRequest(http.MethodPost, "/api/v1/projects/"+project.Identity+"/sources", body)
	req.Header.Set("Content-Type", writer.FormDataContentType())
	req.Header.Set("Authorization", "Bearer test-token")
	rec := httptest.NewRecorder()

	router.ServeHTTP(rec, req)

	require.Equal(t, http.StatusInternalServerError, rec.Code, rec.Body.String())
	require.NotContains(t, rec.Body.String(), storageRoot)
	entries, err := os.ReadDir(storageRoot)
	require.NoError(t, err)
	require.Empty(t, entries, "source 元数据失败后存储目录应为空")
}

func TestFileRegistrarRejectsRequestOverConfiguredUploadLimit(t *testing.T) {
	router, _, project, storageRoot := newFileHandlerTestRouterWithLimit(t, 1, 1, 256)
	body := &bytes.Buffer{}
	writer := multipart.NewWriter(body)
	part, err := writer.CreateFormFile("file", "oversize.bin")
	require.NoError(t, err)
	_, err = part.Write(bytes.Repeat([]byte("x"), 1024))
	require.NoError(t, err)
	require.NoError(t, writer.Close())
	req := httptest.NewRequest(http.MethodPost, "/api/v1/projects/"+project.Identity+"/sources", body)
	req.Header.Set("Content-Type", writer.FormDataContentType())
	req.Header.Set("Authorization", "Bearer test-token")
	rec := httptest.NewRecorder()

	router.ServeHTTP(rec, req)

	require.Equal(t, http.StatusRequestEntityTooLarge, rec.Code, rec.Body.String())
	var payload httpx.ErrorEnvelope
	require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &payload))
	require.Equal(t, "payload_too_large", payload.Error.Code)
	require.Equal(t, "上传内容超过大小限制", payload.Error.Message)
	entries, err := os.ReadDir(storageRoot)
	require.NoError(t, err)
	require.Empty(t, entries)
}

func TestFileRegistrarLogsCleanupFailureWithoutLeakingStorageRoot(t *testing.T) {
	router, database, project, storageRoot, service := newFileHandlerTestRouterWithService(t, 1, 1, DefaultMaxUploadBytes)
	require.NoError(t, database.Callback().Create().Before("gorm:create").Register("test:fail_source_create_for_cleanup_log", func(tx *gorm.DB) {
		if tx.Statement.Schema != nil && tx.Statement.Schema.Table == (models.SenlinAgentSource{}).TableName() {
			tx.AddError(errors.New("forced source create failure"))
		}
	}))
	service.remove = func(path string) error {
		if strings.HasPrefix(filepath.Base(path), ".upload-") {
			return os.Remove(path)
		}
		return fmt.Errorf("cleanup blocked for %s", path)
	}
	var serverLog bytes.Buffer
	previousLogOutput := log.Writer()
	log.SetOutput(&serverLog)
	t.Cleanup(func() { log.SetOutput(previousLogOutput) })
	body := &bytes.Buffer{}
	writer := multipart.NewWriter(body)
	part, err := writer.CreateFormFile("file", "cleanup-failure.txt")
	require.NoError(t, err)
	_, err = part.Write([]byte("content"))
	require.NoError(t, err)
	require.NoError(t, writer.Close())
	req := httptest.NewRequest(http.MethodPost, "/api/v1/projects/"+project.Identity+"/sources", body)
	req.Header.Set("Content-Type", writer.FormDataContentType())
	req.Header.Set("Authorization", "Bearer test-token")
	rec := httptest.NewRecorder()

	router.ServeHTTP(rec, req)

	require.Equal(t, http.StatusInternalServerError, rec.Code, rec.Body.String())
	require.NotContains(t, rec.Body.String(), storageRoot)
	require.Contains(t, serverLog.String(), "source file cleanup failed")
	require.Contains(t, serverLog.String(), storageRoot)
}

func newFileHandlerTestRouter(t *testing.T, currentUserID, ownerID uint) (*gin.Engine, *gorm.DB, models.SenlinAgentProject, string) {
	return newFileHandlerTestRouterWithLimit(t, currentUserID, ownerID, DefaultMaxUploadBytes)
}

func newFileHandlerTestRouterWithLimit(t *testing.T, currentUserID, ownerID uint, maxUploadBytes int64) (*gin.Engine, *gorm.DB, models.SenlinAgentProject, string) {
	router, database, project, storageRoot, _ := newFileHandlerTestRouterWithService(t, currentUserID, ownerID, maxUploadBytes)
	return router, database, project, storageRoot
}

func newFileHandlerTestRouterWithService(t *testing.T, currentUserID, ownerID uint, maxUploadBytes int64) (*gin.Engine, *gorm.DB, models.SenlinAgentProject, string, *Service) {
	t.Helper()
	database, err := gorm.Open(sqlite.Open(fmt.Sprintf("file:%s?mode=memory&cache=shared", t.Name())), &gorm.Config{TranslateError: true})
	require.NoError(t, err)
	require.NoError(t, models.AutoMigrate(database))
	models.DBService = database
	require.NoError(t, database.Create(&models.SenlinAgentUser{Email: "owner@example.com", DisplayName: "Owner", PasswordHash: "hash"}).Error)
	require.NoError(t, database.Create(&models.SenlinAgentUser{Email: "other@example.com", DisplayName: "Other", PasswordHash: "hash"}).Error)
	project := models.SenlinAgentProject{OwnerID: ownerID, Name: "Files", Identifier: fmt.Sprintf("FILES-%d", ownerID)}
	require.NoError(t, database.Create(&project).Error)
	storageRoot := t.TempDir()
	service := NewService(storageRoot, database)
	router := httpx.NewProtectedRouter(
		config.Config{Env: "test"},
		func(string) (uint, error) { return currentUserID, nil },
		NewHandler(service, maxUploadBytes),
	)
	return router, database, project, storageRoot, service
}