package growth

import "testing"

func TestCatalog1405IsValidAndDefensivelyCopied(t *testing.T) {
	first := Catalog1405()
	if err := ValidateCatalog(first); err != nil {
		t.Fatalf("catalog should be valid: %v", err)
	}
	first[0].Tags[0] = "mutated"
	second := Catalog1405()
	if second[0].Tags[0] == "mutated" {
		t.Fatal("catalog tags escaped through a shared backing array")
	}
}

func TestValidateCatalogRejectsDuplicateAndIncompleteEvents(t *testing.T) {
	event := officialEvent("duplicate", "رویداد", "2026-01-01", "2026-01-01", "family", false, []string{"tag"})
	if err := ValidateCatalog([]Event{event, event}); err == nil {
		t.Fatal("expected duplicate id error")
	}
	event.Source = ""
	if err := ValidateCatalog([]Event{event}); err == nil {
		t.Fatal("expected missing source error")
	}
}

func TestCatalogCoversImportedHistoryAndForecastHorizon(t *testing.T) {
	catalog := Catalog1405()
	if catalog[0].StartDate.After(date("2026-01-03")) || catalog[len(catalog)-1].EndDate.Before(date("2026-09-28")) {
		t.Fatalf("catalog coverage is incomplete: %s..%s", catalog[0].StartDate, catalog[len(catalog)-1].EndDate)
	}
	var scoped bool
	for _, event := range catalog {
		if event.ID == "back-to-school-1405" {
			scoped = !event.Universal && len(event.Categories) == 2
		}
	}
	if !scoped {
		t.Fatal("back-to-school event must preserve explicit category scope")
	}
}

func TestAnalyzeEventEffectExcludesCatalogEventsFromBaseline(t *testing.T) {
	target := Event{ID: "target", StartDate: date("2026-05-02"), EndDate: date("2026-05-02")}
	excluded := Event{ID: "other", StartDate: target.StartDate.AddDate(0, 0, -7), EndDate: target.StartDate.AddDate(0, 0, -7)}
	history := make([]DailyPoint, 0, 9)
	for week := 1; week <= 8; week++ {
		count := int64(30)
		if week == 1 {
			count = 1_000
		}
		history = append(history, DailyPoint{Date: target.StartDate.AddDate(0, 0, -7*week), SessionCount: count, PaidSessionCount: count, PaidAmountRial: count * 100})
	}
	history = append(history, DailyPoint{Date: target.StartDate, SessionCount: 50, PaidSessionCount: 50, PaidAmountRial: 5_000})
	effect := AnalyzeEventEffect(history, target, []Event{excluded})
	if effect.ObservationCount != 7 || effect.BaselineSessionCount != 30 || !effect.MaterialWin {
		t.Fatalf("catalog event polluted baseline: %+v", effect)
	}
}

func TestAnalyzeEventEffectUsesCompleteComparableWindows(t *testing.T) {
	target := Event{ID: "two-day", StartDate: date("2026-05-02"), EndDate: date("2026-05-03")}
	history := []DailyPoint{
		{Date: date("2026-04-25"), SessionCount: 60, PaidSessionCount: 50, PaidAmountRial: 5_000},
		{Date: date("2026-04-26"), SessionCount: 60, PaidSessionCount: 50, PaidAmountRial: 5_000},
		{Date: date("2026-04-18"), SessionCount: 1_000, PaidSessionCount: 1_000, PaidAmountRial: 100_000}, // fragmented week, next day absent
		{Date: date("2026-04-11"), SessionCount: 60, PaidSessionCount: 50, PaidAmountRial: 5_000},
		{Date: date("2026-04-12"), SessionCount: 60, PaidSessionCount: 50, PaidAmountRial: 5_000},
		{Date: date("2026-04-04"), SessionCount: 60, PaidSessionCount: 50, PaidAmountRial: 5_000},
		{Date: date("2026-04-05"), SessionCount: 60, PaidSessionCount: 50, PaidAmountRial: 5_000},
		{Date: date("2026-03-28"), SessionCount: 60, PaidSessionCount: 50, PaidAmountRial: 5_000},
		{Date: date("2026-03-29"), SessionCount: 60, PaidSessionCount: 50, PaidAmountRial: 5_000},
		{Date: target.StartDate, SessionCount: 80, PaidSessionCount: 75, PaidAmountRial: 7_500},
		{Date: target.EndDate, SessionCount: 80, PaidSessionCount: 75, PaidAmountRial: 7_500},
	}
	effect := AnalyzeEventEffect(history, target, nil)
	if effect.ObservationCount != 4 || effect.BaselineSessionCount != 120 || effect.ActualSessionCount != 160 || effect.PaidSessionUpliftBPS != 5_000 {
		t.Fatalf("unexpected complete-window effect: %+v", effect)
	}
}

func TestForecastKeepsPoorBacktestVisibleWithLowConfidence(t *testing.T) {
	start := date("2026-07-01")
	history := make([]DailyPoint, 0, 140)
	for i := 140; i > 0; i-- {
		value := int64(100)
		if i%2 == 0 {
			value = 1_000
		}
		history = append(history, DailyPoint{Date: start.AddDate(0, 0, -i), SessionCount: value, PaidSessionCount: value, PaidAmountRial: value * 1_000})
	}
	forecast := BuildForecast(history, nil, start, 90)
	if forecast.Backtest.Origins < 4 || forecast.Confidence != ConfidenceLow || len(forecast.Points) != 90 {
		t.Fatalf("poor model should remain visible with low confidence: %+v", forecast)
	}
}

func TestBacktestUsesProductionTrendPredictorAcrossFourteenDayHorizons(t *testing.T) {
	start := date("2026-07-01")
	history := make([]DailyPoint, 0, 140)
	for index := 0; index < 140; index++ {
		block := index / 28
		value := int64(100 + block*20)
		history = append(history, DailyPoint{Date: start.AddDate(0, 0, index-140), SessionCount: value, PaidSessionCount: value, PaidAmountRial: value * 1_000})
	}
	forecast := BuildForecast(history, nil, start, 90)
	if forecast.Backtest.Origins < 4 || forecast.Confidence == ConfidenceInsufficientData {
		t.Fatalf("trend-aware rolling backtest should be usable: %+v", forecast.Backtest)
	}
}