package adapter

import (
	"errors"
	"fmt"
	"testing"
)

// selfDescribedFailure 是自描述投递失败的替身（适配器实现 DeliveryFailure 的最小形状）。
type selfDescribedFailure struct {
	category DeliveryCategory
	channel  string
	text     string
}

func (e *selfDescribedFailure) Error() string { return e.text }

func (e *selfDescribedFailure) DeliveryCategory() DeliveryCategory { return e.category }

func (e *selfDescribedFailure) DeliveryChannel() string { return e.channel }

// TestDeliveryCategoryOf 锁定原因码口径：自报优先、契约层哨兵次之、兜底
// CategoryFailed —— 绝不替一个没说清楚原因的错误编一个更精确的码。
func TestDeliveryCategoryOf(t *testing.T) {
	t.Parallel()
	window := &selfDescribedFailure{
		category: "proactive_window_closed",
		channel:  "weixin-ilink",
		text:     "weixin_ilink: proactive push outside 24h window",
	}
	tests := []struct {
		name string
		err  error
		want DeliveryCategory
	}{
		{name: "没有失败就没有码", err: nil, want: ""},
		{name: "适配器自报的码被采信", err: window, want: "proactive_window_closed"},
		{name: "多气泡包装不藏自报码", err: fmt.Errorf("channelbridge: send bubble #1 of 2: %w", window), want: "proactive_window_closed"},
		{name: "桥接器包装不藏自报码", err: fmt.Errorf("channelbridge: send proactive via %q: %w", "weixin-ilink", window), want: "proactive_window_closed"},
		{name: "未连接", err: ErrNotConnected, want: CategoryNotConnected},
		{name: "不支持", err: fmt.Errorf("adapter: send: %w", ErrUnsupported), want: CategoryUnsupported},
		{name: "已关闭", err: ErrClosed, want: CategoryClosed},
		{name: "无自报的裸错误落兜底", err: errors.New("boom"), want: CategoryFailed},
		{name: "自报空码落兜底（不编更精确的码）", err: &selfDescribedFailure{text: "boom"}, want: CategoryFailed},
	}
	for _, tc := range tests {
		tc := tc
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			if got := DeliveryCategoryOf(tc.err); got != tc.want {
				t.Fatalf("DeliveryCategoryOf(%v) = %q, want %q", tc.err, got, tc.want)
			}
		})
	}
}

// TestDeliveryChannelOf 锁定渠道自报口径：只有自报才有渠道名，未自报是**空串**
// （= 不知道），绝不替它猜一个平台名。
func TestDeliveryChannelOf(t *testing.T) {
	t.Parallel()
	window := &selfDescribedFailure{category: "proactive_window_closed", channel: "weixin-ilink", text: "closed"}
	if got := DeliveryChannelOf(fmt.Errorf("channelbridge: send bubble #1 of 2: %w", window)); got != "weixin-ilink" {
		t.Fatalf("DeliveryChannelOf(wrapped) = %q, want weixin-ilink", got)
	}
	if got := DeliveryChannelOf(fmt.Errorf("channelbridge: no connected owner IM channel for proactive push")); got != "" {
		t.Fatalf("DeliveryChannelOf(unreported) = %q, want empty (unknown)", got)
	}
	if got := DeliveryChannelOf(nil); got != "" {
		t.Fatalf("DeliveryChannelOf(nil) = %q, want empty", got)
	}
	if got := DeliveryChannelOf(ErrNotConnected); got != "" {
		t.Fatalf("DeliveryChannelOf(ErrNotConnected) = %q, want empty", got)
	}
}