package backthink

import (
	"testing"
	"time"
)

// dayAt 返回 UTC 的午后时间（在安静时段窗口之外）。
func dayAt() time.Time { return time.Date(2026, 9, 6, 14, 0, 0, 0, time.UTC) }

// nightAt 返回 UTC 的 02:00（在默认 23-7 安静窗口之内）。
func nightAt() time.Time { return time.Date(2026, 9, 6, 2, 0, 0, 0, time.UTC) }

// testBackthink 用归一化的空 Config 构建 Backthink，因此 Decide 使用
// 默认安静时段窗口（23:00-07:00）。
func testBackthink() *Backthink {
	return &Backthink{cfg: normalize(Config{})}
}

func TestDecide_DoNotDisturb(t *testing.T) {
	t.Parallel()
	b := testBackthink()
	// 所有用例都带上她的结论要求推送（ConclusionPush），确保命中的是级联本身
	// 而不是「结论不推」的短路。
	cases := []struct {
		name string
		in   DecisionInput
		want bool
	}{
		{
			name: "她的结论不推送_不推送",
			in:   DecisionInput{Trigger: "iot.device_update", Import: ImportanceCritical, At: dayAt(), UserState: UserState{}},
			want: false,
		},
		{
			name: "凌晨+睡眠_不打扰",
			in:   DecisionInput{Trigger: "iot.device_update", Import: ImportanceNormal, At: nightAt(), UserState: UserState{Sleeping: true}, ConclusionPush: true},
			want: false,
		},
		{
			name: "睡眠_危急也不打扰",
			in:   DecisionInput{Trigger: "system.event", Import: ImportanceCritical, At: dayAt(), UserState: UserState{Sleeping: true}, ConclusionPush: true},
			want: false,
		},
		{
			name: "上班_不打扰",
			in:   DecisionInput{Trigger: "iot.device_update", Import: ImportanceNormal, At: dayAt(), UserState: UserState{Working: true}, ConclusionPush: true},
			want: false,
		},
		{
			name: "忙碌_普通_不打扰",
			in:   DecisionInput{Trigger: "iot.device_update", Import: ImportanceNormal, At: dayAt(), UserState: UserState{Busy: true}, ConclusionPush: true},
			want: false,
		},
		{
			name: "安静时段_普通_不打扰",
			in:   DecisionInput{Trigger: "iot.device_update", Import: ImportanceNormal, At: nightAt(), UserState: UserState{Boredom: 0.9}, ConclusionPush: true},
			want: false,
		},
		{
			name: "安静时段_心跳_不打扰",
			in:   DecisionInput{Trigger: "heartbeat", Import: ImportanceLow, At: nightAt(), UserState: UserState{}, ConclusionPush: true, Heartbeat: true},
			want: false,
		},
	}
	for _, tc := range cases {
		tc := tc
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			got := b.Decide(tc.in)
			if got.ShouldPush != tc.want {
				t.Fatalf("Decide(%+v).ShouldPush = %v, want %v (reason %q)", tc.in, got.ShouldPush, tc.want, got.Reason)
			}
		})
	}
}

func TestDecide_ShouldPush(t *testing.T) {
	t.Parallel()
	b := testBackthink()
	cases := []struct {
		name string
		in   DecisionInput
	}{
		{
			name: "白天+重要_推",
			in:   DecisionInput{Trigger: "reminder.trigger", Import: ImportanceHigh, At: dayAt(), UserState: UserState{}, ConclusionPush: true},
		},
		{
			name: "白天+危急_推",
			in:   DecisionInput{Trigger: "system.event", Import: ImportanceCritical, At: dayAt(), UserState: UserState{}, ConclusionPush: true},
		},
		{
			name: "白天+普通+她的结论_推",
			in:   DecisionInput{Trigger: "iot.device_update", Import: ImportanceNormal, At: dayAt(), UserState: UserState{Boredom: 0.8}, ConclusionPush: true},
		},
		{
			name: "安静时段+重要_推",
			in:   DecisionInput{Trigger: "reminder.trigger", Import: ImportanceHigh, At: nightAt(), UserState: UserState{}, ConclusionPush: true},
		},
		{
			name: "安静时段+危急_安全域穿透_推",
			in:   DecisionInput{Trigger: "system.event", Import: ImportanceCritical, At: nightAt(), UserState: UserState{}, ConclusionPush: true},
		},
		{
			name: "危急_可打断忙碌_推",
			in:   DecisionInput{Trigger: "system.event", Import: ImportanceCritical, At: dayAt(), UserState: UserState{Working: true}, ConclusionPush: true},
		},
	}
	for _, tc := range cases {
		tc := tc
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			got := b.Decide(tc.in)
			if !got.ShouldPush {
				t.Fatalf("Decide(%+v).ShouldPush = false, want true (reason %q)", tc.in, got.Reason)
			}
		})
	}
}

func TestInQuietHours(t *testing.T) {
	t.Parallel()
	b := &Backthink{cfg: Config{QuietStartHour: 23, QuietEndHour: 7}}
	cases := []struct {
		name string
		at   time.Time
		want bool
	}{
		{name: "午夜", at: time.Date(2026, 9, 6, 0, 0, 0, 0, time.UTC), want: true},
		{name: "凌晨两点", at: nightAt(), want: true},
		{name: "早上七点_偏出", at: time.Date(2026, 9, 6, 7, 0, 0, 0, time.UTC), want: false},
		{name: "傍晚", at: time.Date(2026, 9, 6, 18, 30, 0, 0, time.UTC), want: false},
		{name: "深夜十一点", at: time.Date(2026, 9, 6, 23, 0, 0, 0, time.UTC), want: true},
	}
	for _, tc := range cases {
		tc := tc
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			if got := b.inQuietHours(tc.at); got != tc.want {
				t.Fatalf("inQuietHours(%v) = %v, want %v", tc.at, got, tc.want)
			}
		})
	}
}

// TestClassifyPush 验证主动消息正文映射到预期的风格
// （问候/提醒/分享/关心），使频率门能分别限制每种风格。
func TestClassifyPush(t *testing.T) {
	t.Parallel()
	cases := []struct {
		in   string
		want PushKind
	}{
		{in: "记得明天体检", want: KindReminder},
		{in: "提醒你到点吃药了", want: KindReminder},
		{in: "最近累不累，注意身体", want: KindCare},
		{in: "想你了，照顾好自己", want: KindCare},
		{in: "早安，昨晚睡得好吗", want: KindGreeting},
		{in: "晚上早点睡，晚安", want: KindGreeting},
		{in: "发现一个有意思的地方，分享给你", want: KindShare},
		{in: "跟往常一样没什么特别", want: KindCare}, // no keyword → generic fallback
	}
	for _, tc := range cases {
		if got := classifyPush(tc.in); got != tc.want {
			t.Fatalf("classifyPush(%q) = %v, want %v", tc.in, got, tc.want)
		}
	}
}

// TestDecide_ActivityGate 验证活动感知软门：刚开始的
// 对话会扣下琐碎内容（critical 除外），长期静默的主人只会被
// 重要事件唤醒——但心跳轮除外，它永远不会被长期
// 静默的间隔拦下（裁决 07.4.3）——而中间地带不会过度抑制。
func TestDecide_ActivityGate(t *testing.T) {
	t.Parallel()
	b := testBackthink()

	// 刚聊过（在 RecentChatCooldown=10min 内）：白天普通推送
	// 会被扣下，除非该事件是安全关键。
	fresh := DecisionInput{
		Import:         ImportanceNormal,
		At:             dayAt(),
		UserState:      UserState{Boredom: 0.9},
		LastActivity:   dayAt().Add(-5 * time.Minute),
		HasActivity:    true,
		ConclusionPush: true,
	}
	if got := b.Decide(fresh); got.ShouldPush {
		t.Fatalf("fresh conversation should hold a normal push, got %+v", got)
	}
	fresh.Import = ImportanceCritical
	if got := b.Decide(fresh); !got.ShouldPush {
		t.Fatalf("critical event should push even in a fresh conversation, got %+v", got)
	}

	// 离开很久（> longIdleThreshold）：只有重要事件值得
	// 唤醒——但心跳轮仍会通过（裁决 07.4.3 长期静默段不拦心跳）。
	idle := DecisionInput{
		Import:         ImportanceNormal,
		At:             dayAt(),
		UserState:      UserState{Boredom: 0.9},
		LastActivity:   dayAt().Add(-3 * time.Hour),
		HasActivity:    true,
		ConclusionPush: true,
	}
	if got := b.Decide(idle); got.ShouldPush {
		t.Fatalf("long idle should hold a normal event push, got %+v", got)
	}
	idle.Import = ImportanceHigh
	if got := b.Decide(idle); !got.ShouldPush {
		t.Fatalf("long idle high-importance should push, got %+v", got)
	}
	idle.Import = ImportanceLow
	idle.Heartbeat = true
	if got := b.Decide(idle); !got.ShouldPush {
		t.Fatalf("long idle heartbeat should still push (07.4.3), got %+v", got)
	}

	// 中等活动（30 分钟前）不会被过度抑制。
	middle := DecisionInput{
		Import:         ImportanceNormal,
		At:             dayAt(),
		UserState:      UserState{Boredom: 0.9},
		LastActivity:   dayAt().Add(-30 * time.Minute),
		HasActivity:    true,
		ConclusionPush: true,
	}
	if got := b.Decide(middle); !got.ShouldPush {
		t.Fatalf("middle-band activity should allow a normal push, got %+v", got)
	}
}