package handlers_test

import (
	"bytes"
	"encoding/json"
	"fmt"
	"net/http/httptest"
	"os"
	"path/filepath"
	"testing"
	"time"

	"github.com/gin-gonic/gin"

	"booklib/cmd/webui/api"
	"booklib/internal/auth"
	"booklib/internal/config"
	"booklib/internal/ports/portsfake"
)

// testEnv 是纯 fake 装配(Task 27):无 PG/Redis。请求走 api.NewRouter 组装的
// 真实 engine,因此认证/鉴权中间件、路由匹配与 gin 的 header 落盘行为都被覆盖;
// 集成测试(auth_test.go 的 setupAPI)另走真库,两层互补。
type testEnv struct {
	cfg       *config.Config
	router    *gin.Engine
	users     *portsfake.Users
	libs      *portsfake.Libraries
	books     *portsfake.Books
	progress  *portsfake.Progress
	bookmarks *portsfake.Bookmarks
	rl        *portsfake.RateLimiter
	sc        *portsfake.Scanner
	med       *portsfake.Media
	up        *portsfake.Uploads
	booksDir  string
}

func newTestEnv(t *testing.T) *testEnv {
	t.Helper()
	gin.SetMode(gin.TestMode)
	resolved, err := filepath.EvalSymlinks(t.TempDir())
	if err != nil {
		t.Fatal(err)
	}
	cfg := &config.Config{Addr: ":8080", JWTSecret: []byte("s3cret"), UploadMaxMB: 1,
		ScanInterval: time.Minute, BooksDir: resolved, CacheDir: t.TempDir(),
		TrustedProxies: []string{"172.16.0.0/12"}}
	users := portsfake.NewUsers()
	libs := portsfake.NewLibraries()
	books := portsfake.NewBooks()
	progress := portsfake.NewProgress(libs, books)
	e := &testEnv{
		cfg: cfg, users: users, libs: libs, books: books,
		progress: progress, bookmarks: portsfake.NewBookmarks(),
		rl: portsfake.NewRateLimiter(), sc: portsfake.NewScanner(),
		med: portsfake.NewMedia(), up: portsfake.NewUploads(),
		booksDir: resolved,
	}
	e.router = api.NewRouter(cfg, users, libs, books, progress, e.bookmarks,
		e.rl, e.sc, e.med, e.up)
	return e
}

// token 签发一个带角色的 JWT(uid 固定 1,与 fake 里 seed 的用户对应)。
func (e *testEnv) token(t *testing.T, role string, uid int64) string {
	t.Helper()
	tok, err := auth.Sign(e.cfg.JWTSecret, uid, role)
	if err != nil {
		t.Fatal(err)
	}
	return tok
}

// do 以 Bearer token 走完整 engine;body 非 nil 时按 JSON 发送。
func (e *testEnv) do(t *testing.T, method, path, tok string, body any) *httptest.ResponseRecorder {
	t.Helper()
	var reader *bytes.Reader
	if body != nil {
		b, err := json.Marshal(body)
		if err != nil {
			t.Fatal(err)
		}
		reader = bytes.NewReader(b)
	} else {
		reader = bytes.NewReader(nil)
	}
	req := httptest.NewRequest(method, path, reader)
	if tok != "" {
		req.Header.Set("Authorization", "Bearer "+tok)
	}
	if body != nil {
		req.Header.Set("Content-Type", "application/json")
	}
	w := httptest.NewRecorder()
	e.router.ServeHTTP(w, req)
	return w
}

// jsonBody 解析响应体为 map。
func jsonBody(t *testing.T, w *httptest.ResponseRecorder) map[string]any {
	t.Helper()
	var out map[string]any
	if err := json.Unmarshal(w.Body.Bytes(), &out); err != nil {
		t.Fatalf("unmarshal %q: %v", w.Body.String(), err)
	}
	return out
}

// jsonUnmarshal 解析响应体到任意目标(slice/struct)。
func jsonUnmarshal(w *httptest.ResponseRecorder, dst any) error {
	return json.Unmarshal(w.Body.Bytes(), dst)
}

// errCode 取 error.code 字段(错误响应契约的核心)。
func errCode(t *testing.T, w *httptest.ResponseRecorder) string {
	t.Helper()
	body := jsonBody(t, w)
	e, _ := body["error"].(map[string]any)
	if e == nil {
		t.Fatalf("no error object in %q", w.Body.String())
	}
	return fmt.Sprint(e["code"])
}

// seedLib 建一个 root 落在 BooksDir 内的库(fake 行 + 真实目录),返回 id 与 root。
func (e *testEnv) seedLib(t *testing.T, name string) (int64, string) {
	t.Helper()
	root := filepath.Join(e.booksDir, name)
	if err := os.MkdirAll(root, 0o755); err != nil {
		t.Fatal(err)
	}
	return e.libs.Seed(name, root), root
}

// httpOK 断言状态码,失败时带上响应体便于定位。
func httpOK(t *testing.T, w *httptest.ResponseRecorder, want int, what string) {
	t.Helper()
	if w.Code != want {
		t.Fatalf("%s: want %d got %d body=%q", what, want, w.Code, w.Body.String())
	}
}