package handler

import (
	"strings"
	"testing"
)

func TestValidateImageFileRejectsOversize(t *testing.T) {
	if err := validateImageFile("a.png", maxImageSize+1); err == nil {
		t.Error("超过 5MB 的图片应被拒绝")
	}
}

func TestValidateImageFileRejectsEmptyAndBadExt(t *testing.T) {
	if err := validateImageFile("a.png", 0); err == nil {
		t.Error("空文件应被拒绝")
	}
	if err := validateImageFile("a.txt", 1024); err == nil {
		t.Error("非图片扩展名应被拒绝")
	}
}

func TestValidateImageFileAcceptsAllowed(t *testing.T) {
	for _, name := range []string{"a.jpg", "a.jpeg", "a.png", "a.webp"} {
		if err := validateImageFile(name, 1024); err != nil {
			t.Errorf("%s 应被允许: %v", name, err)
		}
	}
}

func TestImageContentType(t *testing.T) {
	cases := map[string]string{
		".jpg":  "image/jpeg",
		".jpeg": "image/jpeg",
		".png":  "image/png",
		".webp": "image/webp",
	}
	for ext, want := range cases {
		got, ok := imageContentType(ext)
		if !ok || got != want {
			t.Errorf("imageContentType(%s) = %q, %v; want %q", ext, got, ok, want)
		}
	}
	if _, ok := imageContentType(".gif"); ok {
		t.Error(".gif 不应被支持")
	}
}

func TestBuildImageKey(t *testing.T) {
	key, ext, err := buildImageKey("病蚕照片.PNG")
	if err != nil {
		t.Fatalf("buildImageKey 失败: %v", err)
	}
	if !strings.HasPrefix(key, "knowledge/") {
		t.Errorf("key 应以 knowledge/ 开头: %s", key)
	}
	if !strings.HasSuffix(key, ".png") {
		t.Errorf("key 应以 .png 结尾: %s", key)
	}
	if ext != ".png" {
		t.Errorf("ext = %s, want .png", ext)
	}
	if len(key) <= len("knowledge/")+8 {
		t.Errorf("key 应包含日期与随机部分: %s", key)
	}
}