package creator

import (
	"testing"
	"time"
)

func TestComputeWorkGrowth(t *testing.T) {
	now := time.Date(2026, 9, 27, 12, 0, 0, 0, time.UTC)
	likes := func(at time.Time, value int64) MetricPoint {
		return MetricPoint{CollectedAt: at, Likes: &value}
	}
	tooOld := now.Add(-72 * time.Hour)

	t.Run("full baseline inside window", func(t *testing.T) {
		points := []MetricPoint{
			likes(tooOld, 100),
			likes(now.Add(-25*time.Hour), 200), // 窗口起点前最近点 → 基线
			likes(now.Add(-2*time.Hour), 500),
		}
		growth := computeWorkGrowth(points, now, 24)
		if growth.Likes == nil || *growth.Likes != 300 || growth.Coverage != "full" {
			t.Fatalf("unexpected growth: %+v", growth)
		}
	})

	t.Run("partial when only one point", func(t *testing.T) {
		points := []MetricPoint{likes(now.Add(-2*time.Hour), 500)}
		growth := computeWorkGrowth(points, now, 24)
		if growth.Likes == nil || *growth.Likes != 0 || growth.Coverage != "partial" {
			t.Fatalf("unexpected growth: %+v", growth)
		}
	})

	t.Run("partial falls back to first point", func(t *testing.T) {
		points := []MetricPoint{likes(now.Add(-20*time.Hour), 100), likes(now.Add(-2*time.Hour), 500)}
		growth := computeWorkGrowth(points, now, 24)
		// 两个点都在窗口内、窗口前无基线 → 以首点近似，partial。
		if growth.Likes == nil || *growth.Likes != 400 || growth.Coverage != "partial" {
			t.Fatalf("unexpected growth: %+v likes=%v", growth, *growth.Likes)
		}
	})

	t.Run("old pre-window baseline counts as full", func(t *testing.T) {
		points := []MetricPoint{likes(tooOld, 100), likes(now.Add(-2*time.Hour), 500)}
		growth := computeWorkGrowth(points, now, 24)
		// 窗口前存在真实基线（72h 前）→ full；增量跨 72h 但可比。
		if growth.Likes == nil || *growth.Likes != 400 || growth.Coverage != "full" {
			t.Fatalf("unexpected growth: %+v", growth)
		}
	})

	t.Run("no points", func(t *testing.T) {
		if growth := (WorkGrowth{}); computeWorkGrowth(nil, now, 24) != growth {
			t.Fatal("empty points must yield zero growth")
		}
	})
}

func TestApplyWorkGrowthFilterSortsAndFilters(t *testing.T) {
	mk := func(id string, growth int64) (Work, WorkGrowth) {
		value := growth
		return Work{ID: id}, WorkGrowth{Likes: &value, Coverage: "full"}
	}
	w1, g1 := mk("a", 100)
	w2, g2 := mk("b", 900)
	w3, _ := mk("c", 0) // 无采样点：不附加增速
	works := []Work{w1, w2, w3}
	growth := map[string]WorkGrowth{"a": g1, "b": g2}

	min := int64(50)
	filtered, err := ApplyWorkGrowthFilter(works, growth, WorkGrowthFilter{Hours: 24, MinLikes: &min})
	if err != nil {
		t.Fatal(err)
	}
	if len(filtered) != 2 || filtered[0].ID != "b" || filtered[1].ID != "a" {
		t.Fatalf("unexpected filter/sort result: %+v", filtered)
	}
	if filtered[0].LikesGrowth == nil || *filtered[0].LikesGrowth != 900 {
		t.Fatalf("growth not attached: %+v", filtered[0])
	}
}