package backthink

import (
	"context"
	"errors"
	"strings"
	"testing"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/channel/adapter"
)

// 本文件锁定切片 P0「她主动找你」的**活跃客户端路由口径**：
//
//   - PushResult.Detail 必须把「送到了几条连接」与「有没有落进主会话」**分开**
//     报告 —— 修复前那句「delivered to 2 active client(s)」被读者当成「已推送
//     （刷新也在）」，而当时一行都没落库；
//   - 一次推送**至多让一个 sink 成功**（IM 桥与活跃客户端互斥），这正是
//     「主会话里不会出现双份」的结构性依据：两条路由各自落库一次，而一次推送
//     只走其中一条。

// TestPusher_ActiveDetailReportsPersistence 验证 Detail 分别报告投递数与落库。
func TestPusher_ActiveDetailReportsPersistence(t *testing.T) {
	t.Parallel()
	tests := []struct {
		name       string
		active     *mockActive
		wantPushed bool
		wantIn     string
		wantNotIn  string
	}{
		{
			name:       "投递成功且已落库",
			active:     &mockActive{n: 2, persisted: true},
			wantPushed: true,
			wantIn:     "persisted to main session",
			wantNotIn:  "not persisted",
		},
		{
			name:       "投递成功但未落库（故障可见）",
			active:     &mockActive{n: 2, persisted: false},
			wantPushed: true,
			wantIn:     "not persisted to main session",
		},
		{
			name:       "无在线客户端但已落库",
			active:     &mockActive{n: 0, persisted: true},
			wantPushed: false,
			wantIn:     "recorded in main session",
		},
	}
	for _, tc := range tests {
		tc := tc
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			p := newPusher(tc.active, nil, &mockGate{allow: true}, discardLog())
			res := p.Push(context.Background(), PushRequest{
				ChannelHint: channelWeb,
				Message:     adapter.UnifiedMessage{Content: "记得喝水哦"},
			})
			if res.Pushed != tc.wantPushed {
				t.Fatalf("Pushed = %v, want %v (res=%+v)", res.Pushed, tc.wantPushed, res)
			}
			if !strings.Contains(res.Detail, tc.wantIn) {
				t.Fatalf("Detail = %q, want it to contain %q", res.Detail, tc.wantIn)
			}
			if tc.wantNotIn != "" && strings.Contains(res.Detail, tc.wantNotIn) {
				t.Fatalf("Detail = %q, must not contain %q", res.Detail, tc.wantNotIn)
			}
		})
	}
}

// TestPusher_OnePushSucceedsOnAtMostOneSink 验证一次推送**至多让一个 sink 成功**
// —— 互斥是「主会话里不会双份」的结构性依据。IM 失败后的活跃客户端降级是同一
// 次推送内的兜底：失败的 IM 什么都没写，因此整体仍只有一条记录。
func TestPusher_OnePushSucceedsOnAtMostOneSink(t *testing.T) {
	t.Parallel()
	tests := []struct {
		name           string
		hint           string
		imErr          error
		activeN        int
		wantIMCalls    int
		wantActiveCall int
	}{
		{name: "web 提示只打活跃客户端", hint: channelWeb, activeN: 1, wantIMCalls: 0, wantActiveCall: 1},
		{name: "auto 提示 IM 可用时只打 IM", hint: channelAuto, activeN: 2, wantIMCalls: 1, wantActiveCall: 0},
		{name: "IM 失败时降级到活跃客户端", hint: channelAuto, imErr: errors.New("no owner IM channel"), activeN: 1, wantIMCalls: 1, wantActiveCall: 1},
	}
	for _, tc := range tests {
		tc := tc
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			active := &mockActive{n: tc.activeN, persisted: true}
			im := &mockIMAdapter{err: tc.imErr}
			p := newPusher(active, im, &mockGate{allow: true}, discardLog())

			res := p.Push(context.Background(), PushRequest{
				ChannelHint: tc.hint,
				Message:     adapter.UnifiedMessage{Content: "记得喝水哦"},
			})
			if im.count() != tc.wantIMCalls || active.calls != tc.wantActiveCall {
				t.Fatalf("sink calls: im=%d (want %d) active=%d (want %d)",
					im.count(), tc.wantIMCalls, active.calls, tc.wantActiveCall)
			}
			// 成功的 sink 至多一个：能落库的路径因此也至多一条。
			imOK := tc.imErr == nil && tc.wantIMCalls == 1
			activeOK := tc.activeN > 0 && tc.wantActiveCall == 1
			if imOK && activeOK {
				t.Fatalf("both sinks succeeded in one push (res=%+v)", res)
			}
			if !imOK && !activeOK && res.Pushed {
				t.Fatalf("Pushed = true without a successful sink (res=%+v)", res)
			}
		})
	}
}