// Copyright 2026 tamakyi. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package route

import (
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"github.com/flamego/flamego"
	"github.com/stretchr/testify/require"
)

// TestRecoveryMiddlewareRendersHTML 锁住 panic 的对外表现。
//
// 改动前用的是 flamego.Recovery()：它直接写纯文本 "Internal Server Error"，
// 用户看到白底黑字两行英文，没有返回入口，也拿不到可以报给我们的编号。
func TestRecoveryMiddlewareRendersHTML(t *testing.T) {
	f := flamego.New()
	f.Use(recoveryMiddleware())
	f.Get("/boom", func() {
		panic("boom")
	})

	req := httptest.NewRequest(http.MethodGet, "/boom", nil)
	resp := httptest.NewRecorder()
	f.ServeHTTP(resp, req)

	require.Equal(t, http.StatusInternalServerError, resp.Code)
	require.True(t, strings.HasPrefix(resp.Header().Get("Content-Type"), "text/html"),
		"必须是 HTML，不能退回纯文本")
	require.Equal(t, "no-store", resp.Header().Get("Cache-Control"))

	body := resp.Body.String()
	require.Contains(t, body, "<!DOCTYPE html>")
	// 中文环境（default lang）下应给出可读文案与返回入口
	require.Contains(t, body, "服务出了点问题")
	require.Contains(t, body, `href="/"`, "错误页必须有返回首页的入口")
	require.NotContains(t, body, "boom", "不能把 panic 内容暴露给用户")
}

// TestRecoveryMiddlewareDoesNotDoubleWrite 响应已写出时不能再写头。
//
// 场景：handler 先写了一部分内容再 panic。这时 HTTP 头已经发出去了，
// 再 WriteHeader 会被 net/http 忽略（并打 superfluous 警告），
// 强行写还会把已经发出去的响应体盖掉。
func TestRecoveryMiddlewareDoesNotDoubleWrite(t *testing.T) {
	f := flamego.New()
	f.Use(recoveryMiddleware())
	f.Get("/half", func(ctx flamego.Context) {
		_, _ = ctx.ResponseWriter().Write([]byte("partial"))
		panic("boom after write")
	})

	req := httptest.NewRequest(http.MethodGet, "/half", nil)
	resp := httptest.NewRecorder()
	f.ServeHTTP(resp, req)

	require.Equal(t, http.StatusOK, resp.Code, "头已发出，状态码不能变")
	require.Equal(t, "partial", resp.Body.String(), "不能把已写出的内容覆盖掉")
}

// TestPickErrorPageLang 错误页语言只能靠 Accept-Language 猜
// （sessioner 是组级中间件，NotFound 不经过它）。
func TestPickErrorPageLang(t *testing.T) {
	cases := []struct {
		name   string
		header string
		want   string
	}{
		{"空 header 用站点默认", "", ""},
		{"英文", "en-US,en;q=0.9", "en"},
		{"日文", "ja-JP,ja;q=0.9", "ja"},
		{"繁体", "zh-TW,zh;q=0.9", "zh-TW"},
		{"zh-Hant 也算繁体", "zh-Hant", "zh-TW"},
		{"简体", "zh-CN,zh;q=0.9", "zh-CN"},
		// 浏览器常把首选语言排在前面，这里按出现顺序取第一个能识别的
		{"首选英文后跟日文", "en-GB,en;q=0.9,ja;q=0.5", "en"},
		{"无法识别时回退默认", "de-DE,fr;q=0.8", ""},
	}

	for _, c := range cases {
		t.Run(c.name, func(t *testing.T) {
			req := httptest.NewRequest(http.MethodGet, "/nope", nil)
			if c.header != "" {
				req.Header.Set("Accept-Language", c.header)
			}
			got := pickErrorPageLang(req)
			if c.want == "" {
				// 回退到站点默认语言，不是空串
				require.NotEmpty(t, got)
				return
			}
			require.Equal(t, c.want, got)
		})
	}
}

// TestWriteErrorPageStatusCodes 404 与 500 各自的状态码与 noindex。
func TestWriteErrorPageStatusCodes(t *testing.T) {
	for _, status := range []int{http.StatusNotFound, http.StatusInternalServerError} {
		f := flamego.New()
		f.Get("/x", func(ctx flamego.Context) {
			writeErrorPage(ctx, status, "error.notFoundTitle", "error.notFoundDesc")
		})

		req := httptest.NewRequest(http.MethodGet, "/x", nil)
		resp := httptest.NewRecorder()
		f.ServeHTTP(resp, req)

		require.Equal(t, status, resp.Code)
		require.Contains(t, resp.Body.String(), `name="robots" content="noindex"`,
			"错误页不该被搜索引擎收录")
	}
}

// TestEscErrorPageText 字典文本里出现引号/尖括号时不能把页面结构弄坏。
func TestEscErrorPageText(t *testing.T) {
	require.Equal(t, "a&quot;b", esc(`a"b`))
	require.Equal(t, "&lt;script&gt;", esc("<script>"))
	require.Equal(t, "a&amp;b", esc("a&b"))
	require.Equal(t, "&#39;x&#39;", esc("'x'"))
}