package handler

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

	"github.com/agentmail/gateway/internal/models"
)

// 400 的信息必须指向具体字段。
//
// 起因：写跨主机验证脚本时把 workspaces 传成了字符串数组，
// 服务端回的是一句固定的 "Invalid JSON" —— 只能靠翻服务端结构体才发现是哪个字段。
// 第三方客户端没有这个条件。
func TestDecodeBodyErrorNamesTheField(t *testing.T) {
	type body struct {
		Name       string             `json:"name"`
		Workspaces []models.Workspace `json:"workspaces"`
	}

	cases := []struct {
		name     string
		payload  string
		wantHas  []string
		wantMiss []string
	}{
		{
			name:    "字段类型不对要说出字段名与期望类型",
			payload: `{"name":"bot","workspaces":["/tmp/ws"]}`,
			// 期望能看出：是 workspaces，要的是 object 数组，给的是 string
			wantHas: []string{"workspaces", "object", "string"},
			// 不该把 Go 类型名漏出去
			wantMiss: []string{"models.Workspace", "[]models"},
		},
		{
			name:    "整个体的类型不对",
			payload: `["not","an","object"]`,
			wantHas: []string{"object"},
		},
		{
			// 截断的 JSON 走的是 io.ErrUnexpectedEOF，不是 json.SyntaxError
			name:    "被截断的体要说明是截断",
			payload: `{"name":`,
			wantHas: []string{"语法", "结束"},
		},
		{
			name:    "非法字符要给出位置",
			payload: `{"name":1x}`,
			wantHas: []string{"语法", "字节"},
		},
		{
			name:    "空体单独说明",
			payload: ``,
			wantHas: []string{"为空"},
		},
	}

	for _, c := range cases {
		t.Run(c.name, func(t *testing.T) {
			r := httptest.NewRequest(http.MethodPost, "/x", strings.NewReader(c.payload))
			w := httptest.NewRecorder()

			var v body
			if DecodeBody(w, r, &v) {
				t.Fatal("这个体应当解析失败")
			}
			if w.Code != http.StatusBadRequest {
				t.Fatalf("状态码应为 400，实际 %d", w.Code)
			}

			var resp map[string]string
			if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
				t.Fatalf("响应不是 JSON: %v", err)
			}
			msg := resp["error"]
			if msg == "" {
				t.Fatal("error 字段为空")
			}
			for _, want := range c.wantHas {
				if !strings.Contains(msg, want) {
					t.Errorf("信息里应含 %q，实际 %q", want, msg)
				}
			}
			for _, miss := range c.wantMiss {
				if strings.Contains(msg, miss) {
					t.Errorf("信息里不该含 Go 类型名 %q：%q", miss, msg)
				}
			}
		})
	}
}

// 合法请求体不该被拦，也不该写任何响应 ——
// 写了的话调用方接着写自己的响应就成了两次 WriteHeader。
func TestDecodeBodyPassesValidPayload(t *testing.T) {
	type body struct {
		Name       string             `json:"name"`
		Workspaces []models.Workspace `json:"workspaces"`
	}

	payload := `{"name":"bot","workspaces":[{"name":"demo","path":"/tmp/ws"}]}`
	r := httptest.NewRequest(http.MethodPost, "/x", strings.NewReader(payload))
	w := httptest.NewRecorder()

	var v body
	if !DecodeBody(w, r, &v) {
		t.Fatalf("合法体被拒：%s", w.Body.String())
	}
	if w.Body.Len() != 0 {
		t.Errorf("成功时不该写响应体，实际写了 %q", w.Body.String())
	}
	if v.Name != "bot" || len(v.Workspaces) != 1 || v.Workspaces[0].Path != "/tmp/ws" {
		t.Errorf("解析结果不对：%+v", v)
	}
}

// 空数组是合法的 —— 两个正式插件注册时都传 workspaces: []。
func TestDecodeBodyAcceptsEmptyWorkspaces(t *testing.T) {
	type body struct {
		Name       string             `json:"name"`
		Workspaces []models.Workspace `json:"workspaces"`
	}

	r := httptest.NewRequest(http.MethodPost, "/x",
		strings.NewReader(`{"name":"opencode","workspaces":[]}`))
	w := httptest.NewRecorder()

	var v body
	if !DecodeBody(w, r, &v) {
		t.Fatalf("空 workspaces 被拒：%s", w.Body.String())
	}
	if len(v.Workspaces) != 0 {
		t.Errorf("应为空数组，实际 %+v", v.Workspaces)
	}
}