package loop

import (
	"context"
	"errors"
	"fmt"
	"testing"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/model"
)

// fakeSourceErr 模拟 vision 包的 SourceFailure：错误链上能报出来源主机。
type fakeSourceErr struct{ host string }

func (e *fakeSourceErr) Error() string { return "取回失败" }
func (e *fakeSourceErr) ImageSourceHost() string {
	return e.host
}

// TestImageSourceHost 钉住「日志能定位到来源主机」这条契约：错误链上
// 带 ImageSourceHost 的证据要穿透 %w 包装被取出；其它错误一律空串
// （空串表示无从定位，而不是假装有来源）。
func TestImageSourceHost(t *testing.T) {
	t.Parallel()
	cases := []struct {
		name string
		err  error
		want string
	}{
		{name: "nil 错误", err: nil, want: ""},
		{name: "普通错误", err: errors.New("解析失败"), want: ""},
		{name: "包装后的来源错误", err: fmt.Errorf("resolve: %w", &fakeSourceErr{host: "cdn.example.com"}), want: "cdn.example.com"},
		{name: "包装但主机为空", err: fmt.Errorf("resolve: %w", &fakeSourceErr{}), want: ""},
	}
	for _, c := range cases {
		t.Run(c.name, func(t *testing.T) {
			t.Parallel()
			if got := imageSourceHost(c.err); got != c.want {
				t.Fatalf("imageSourceHost = %q, want %q", got, c.want)
			}
		})
	}
}

func TestRun_ImageResolverFoldsToText(t *testing.T) {
	t.Parallel()
	ad := &mockAdapter{chat: []mgResp{{resp: model.Response{Model: "m", Content: "Done."}}}}
	a := newTestAgent(t, ad, nil)
	l := New(Options{
		Agent:     a,
		MaxRounds: 8,
		Vision: ImageResolveFunc(func(_ context.Context, _ model.Message) (model.Message, error) {
			return model.TextMessage(model.RoleUser, "图中是一只猫"), nil
		}),
	})

	in := []model.Message{model.ImageMessage(model.RoleUser, "", "data:image/png;base64,AAAA")}
	if _, err := l.Run(context.Background(), "sess-1", in); err != nil {
		t.Fatalf("Run: %v", err)
	}
	if len(ad.reqs) == 0 {
		t.Fatalf("no model request recorded")
	}
	var userSeen bool
	for _, m := range ad.reqs[0].Messages {
		if m.Role == model.RoleUser {
			userSeen = true
			if messageHasImage(m) {
				t.Fatalf("image still reached the model: %+v", m)
			}
		}
	}
	if !userSeen {
		t.Fatalf("no user message seen by the model")
	}
}

func TestRun_ImageKeptWithoutResolver(t *testing.T) {
	t.Parallel()
	ad := &mockAdapter{chat: []mgResp{{resp: model.Response{Model: "m", Content: "Done."}}}}
	a := newTestAgent(t, ad, nil)
	l := New(Options{Agent: a, MaxRounds: 8})

	in := []model.Message{model.ImageMessage(model.RoleUser, "look", "data:image/png;base64,AAAA")}
	if _, err := l.Run(context.Background(), "sess-1", in); err != nil {
		t.Fatalf("Run: %v", err)
	}
	if len(ad.reqs) == 0 {
		t.Fatalf("no model request recorded")
	}
	var sawImage bool
	for _, m := range ad.reqs[0].Messages {
		if m.Role == model.RoleUser && messageHasImage(m) {
			sawImage = true
		}
	}
	if !sawImage {
		t.Fatalf("expected the image part to pass through without a resolver")
	}
}