package api

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

	"github.com/redis/go-redis/v9"

	"booklib/internal/auth"
	"booklib/internal/db"
	"booklib/internal/redispkg"
	"booklib/internal/scanner"
	"booklib/internal/store"
)

func setupAPI(t *testing.T) (*store.Store, *scanner.Scanner, http.Handler, string) {
	t.Helper()
	url := os.Getenv("DATABASE_URL")
	if url == "" {
		t.Skip("DATABASE_URL not set")
	}
	ctx := context.Background()
	p, _ := db.Connect(ctx, url)
	if err := db.Migrate(ctx, p); err != nil {
		t.Fatal(err)
	}
	st := store.New(p)
	p.Exec(ctx, "DELETE FROM reading_progress; DELETE FROM books; DELETE FROM libraries; DELETE FROM users")
	h, _ := auth.HashPassword(testPW)
	if _, err := st.CreateUser(ctx, "alice", h, "admin"); err != nil {
		t.Fatal(err)
	}
	if _, err := st.CreateUser(ctx, "bob", h, "member"); err != nil {
		t.Fatal(err)
	}
	booksParent := t.TempDir()
	booksDir, err := filepath.EvalSymlinks(booksParent) // macOS 上 /var→/private,root 校验要用真实路径
	if err != nil {
		t.Fatal(err)
	}
	cfg := testCfg()
	cfg.BooksDir = booksDir
	cfg.CacheDir = t.TempDir()
	rdb := redispkg.New(os.Getenv("REDIS_URL"))
	sc := scanner.New(st, cfg, rdb)
	r := NewRouter(cfg, st, rdb, sc)
	if u := os.Getenv("REDIS_URL"); u != "" { // 测试卫生: 共享 redis 上重置登录限流桶, 防跨测试累计 429
		if opt, e := redis.ParseURL(u); e == nil {
			rc := redis.NewClient(opt)
			rc.Del(ctx, "loginrl:192.0.2.1")
			rc.Close()
		}
	}
	return st, sc, r, booksDir
}

// testPW 是唯一的 fixture 口令常量: 直接种子 (HashPassword) 与所有登录/建户必须同值, 且 >=8 位
const testPW = "pw123456"

func do(h http.Handler, method, path, token string, body any) *httptest.ResponseRecorder {
	var r *bytes.Reader
	if body != nil {
		b, _ := json.Marshal(body)
		r = bytes.NewReader(b)
	} else {
		r = bytes.NewReader(nil)
	}
	req := httptest.NewRequest(method, path, r)
	if token != "" {
		req.Header.Set("Authorization", "Bearer "+token)
	}
	w := httptest.NewRecorder()
	h.ServeHTTP(w, req)
	return w
}

func TestLoginMe(t *testing.T) {
	_, _, h, _ := setupAPI(t)
	w := do(h, "POST", "/api/auth/login", "", map[string]string{"username": "alice", "password": testPW})
	if w.Code != 200 {
		t.Fatalf("login %d %s", w.Code, w.Body)
	}
	var tok struct{ Token string }
	json.Unmarshal(w.Body.Bytes(), &tok)
	if tok.Token == "" {
		t.Fatal("no token")
	}
	w = do(h, "GET", "/api/auth/me", tok.Token, nil)
	var me map[string]any
	json.Unmarshal(w.Body.Bytes(), &me)
	if w.Code != 200 || me["username"] != "alice" || me["role"] != "admin" {
		t.Fatalf("me %d %s", w.Code, w.Body)
	}
	// 错密码 → 401 统一错误体
	w = do(h, "POST", "/api/auth/login", "", map[string]string{"username": "alice", "password": "nope"})
	if w.Code != 401 {
		t.Fatalf("want 401 got %d", w.Code)
	}
	// 无 token / 坏 token 访问受保护端点 → 401(me 已注册;books 路由 Task 10 才有)
	if w = do(h, "GET", "/api/auth/me", "", nil); w.Code != 401 {
		t.Fatal("me without token must 401")
	}
	if w = do(h, "GET", "/api/auth/me", "garbage", nil); w.Code != 401 {
		t.Fatal("me with bad token must 401")
	}
}

// 伪造 XFF 换不了限流桶: peer(192.0.2.1)不在可信代理段 → ClientIP 取 peer,XFF 忽略
func TestLoginRateLimitResistsXFFSpoof(t *testing.T) {
	if os.Getenv("REDIS_URL") == "" {
		t.Skip("REDIS_URL not set (no redis → IncrWindow always allows)")
	}
	_, _, h, _ := setupAPI(t) // setupAPI 已重置 loginrl:192.0.2.1
	for i := 1; i <= 6; i++ {
		req := httptest.NewRequest("POST", "/api/auth/login", bytes.NewBufferString(`{"username":"alice","password":"nope"}`))
		req.Header.Set("X-Forwarded-For", fmt.Sprintf("203.0.113.%d", i))
		w := httptest.NewRecorder()
		h.ServeHTTP(w, req)
		if i < 6 && w.Code != http.StatusUnauthorized {
			t.Fatalf("attempt %d: want 401 got %d %s", i, w.Code, w.Body)
		}
		if i == 6 && w.Code != http.StatusTooManyRequests {
			t.Fatalf("attempt 6: spoofed XFF escaped per-peer limit: want 429 got %d", w.Code)
		}
	}
}

func TestMemberCannotWriteUsers(t *testing.T) {
	_, _, h, _ := setupAPI(t)
	w := do(h, "POST", "/api/auth/login", "", map[string]string{"username": "bob", "password": testPW})
	var v struct{ Token string }
	json.Unmarshal(w.Body.Bytes(), &v)
	tok := v.Token
	w = do(h, "POST", "/api/users", tok, map[string]string{"username": "eve", "password": testPW, "role": "member"})
	if w.Code != 403 {
		t.Fatalf("member write users: want 403 got %d", w.Code)
	}
}