package report

import (
	"strings"
	"testing"
	"time"

	"gitea.maximumdirect.net/eric/weatherreporter/internal/timeutil"
)

func TestDailyValidPeriod(t *testing.T) {
	location := mustLoadLocation(t)
	now := mustParse("2026-05-29T17:45:00-05:00")

	resolved, err := Resolve(DailyToday, ResolveRequest{Now: now, Location: location})
	if err != nil {
		t.Fatalf("Resolve() error = %v", err)
	}
	assertPeriod(t, resolved.ValidPeriod, "2026-05-29T00:00:00-05:00", "2026-05-30T00:00:00-05:00")
}

func TestDailyValidPeriodCanUseExplicitDate(t *testing.T) {
	location := mustLoadLocation(t)
	now := mustParse("2026-05-29T17:45:00-05:00")
	date := mustParse("2026-05-31T12:00:00-05:00")

	resolved, err := Resolve(DailyToday, ResolveRequest{Now: now, Location: location, Date: date})
	if err != nil {
		t.Fatalf("Resolve() error = %v", err)
	}
	assertPeriod(t, resolved.ValidPeriod, "2026-05-31T00:00:00-05:00", "2026-06-01T00:00:00-05:00")
}

func TestTomorrowValidPeriodFromEveningGeneration(t *testing.T) {
	location := mustLoadLocation(t)
	now := mustParse("2026-05-29T20:00:00-05:00")

	resolved, err := Resolve(DailyTomorrow, ResolveRequest{Now: now, Location: location})
	if err != nil {
		t.Fatalf("Resolve() error = %v", err)
	}
	assertPeriod(t, resolved.ValidPeriod, "2026-05-30T00:00:00-05:00", "2026-05-31T00:00:00-05:00")
	if resolved.Definition.PromptID != "weather.daily_report" {
		t.Fatalf("PromptID = %q, want weather.daily_report", resolved.Definition.PromptID)
	}
}

func TestThreeDayPeriodCalculation(t *testing.T) {
	location := mustLoadLocation(t)
	now := mustParse("2026-05-29T05:00:00-05:00")

	resolved, err := Resolve(ThreeDay, ResolveRequest{Now: now, Location: location})
	if err != nil {
		t.Fatalf("Resolve() error = %v", err)
	}
	assertPeriod(t, resolved.ValidPeriod, "2026-05-29T05:00:00-05:00", "2026-06-01T00:00:00-05:00")
}

func TestWeekendPeriodCalculation(t *testing.T) {
	location := mustLoadLocation(t)
	tests := []struct {
		name  string
		now   string
		start string
		end   string
	}{
		{name: "monday", now: "2026-05-25T05:00:00-05:00", start: "2026-05-30T00:00:00-05:00", end: "2026-06-01T00:00:00-05:00"},
		{name: "tuesday", now: "2026-05-26T05:00:00-05:00", start: "2026-05-30T00:00:00-05:00", end: "2026-06-01T00:00:00-05:00"},
		{name: "wednesday", now: "2026-05-27T05:00:00-05:00", start: "2026-05-30T00:00:00-05:00", end: "2026-06-01T00:00:00-05:00"},
		{name: "thursday", now: "2026-05-28T05:00:00-05:00", start: "2026-05-30T00:00:00-05:00", end: "2026-06-01T00:00:00-05:00"},
		{name: "friday before evening", now: "2026-05-29T05:00:00-05:00", start: "2026-05-29T18:00:00-05:00", end: "2026-06-01T00:00:00-05:00"},
		{name: "friday after evening", now: "2026-05-29T19:30:00-05:00", start: "2026-05-29T19:30:00-05:00", end: "2026-06-01T00:00:00-05:00"},
		{name: "saturday", now: "2026-05-30T08:00:00-05:00", start: "2026-05-30T08:00:00-05:00", end: "2026-06-01T00:00:00-05:00"},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			resolved, err := Resolve(Weekend, ResolveRequest{Now: mustParse(tt.now), Location: location})
			if err != nil {
				t.Fatalf("Resolve() error = %v", err)
			}
			assertPeriod(t, resolved.ValidPeriod, tt.start, tt.end)
		})
	}
}

func TestWeekendSundayErrors(t *testing.T) {
	location := mustLoadLocation(t)
	_, err := Resolve(Weekend, ResolveRequest{Now: mustParse("2026-05-31T08:00:00-05:00"), Location: location})
	if err == nil {
		t.Fatal("Resolve() error = nil, want Sunday weekend error")
	}
	if !strings.Contains(err.Error(), "Sunday") {
		t.Fatalf("error = %q, want Sunday context", err.Error())
	}
}

func TestStormManualPeriodParsingAndValidation(t *testing.T) {
	location := mustLoadLocation(t)
	period, err := ParseStormPeriod("2026-05-29T18:00", "2026-05-30T06:00:00-05:00", location)
	if err != nil {
		t.Fatalf("ParseStormPeriod() error = %v", err)
	}
	assertPeriod(t, period, "2026-05-29T18:00:00-05:00", "2026-05-30T06:00:00-05:00")

	_, err = ParseStormPeriod("2026-05-30T06:00", "2026-05-29T18:00", location)
	if err == nil {
		t.Fatal("ParseStormPeriod() error = nil, want invalid period error")
	}
}

func TestStormResolve(t *testing.T) {
	location := mustLoadLocation(t)
	resolved, err := Resolve(Storm, ResolveRequest{
		Now:        mustParse("2026-05-29T12:00:00-05:00"),
		Location:   location,
		StormStart: mustParse("2026-05-29T18:00:00-05:00"),
		StormEnd:   mustParse("2026-05-30T06:00:00-05:00"),
	})
	if err != nil {
		t.Fatalf("Resolve() error = %v", err)
	}
	assertPeriod(t, resolved.ValidPeriod, "2026-05-29T18:00:00-05:00", "2026-05-30T06:00:00-05:00")
	if resolved.Definition.ComparisonStrategy != CompareExplicitWindow {
		t.Fatalf("ComparisonStrategy = %q, want explicit event window", resolved.Definition.ComparisonStrategy)
	}
}

func TestMorningBatchSkipsWeekendOnSunday(t *testing.T) {
	location := mustLoadLocation(t)
	resolved, err := DefaultRegistry().BatchReports(Morning, ResolveRequest{
		Now:      mustParse("2026-05-31T06:00:00-05:00"),
		Location: location,
	})
	if err != nil {
		t.Fatalf("BatchReports() error = %v", err)
	}
	ids := resolvedIDs(resolved)
	if strings.Join(ids, ",") != "daily_today,three_day" {
		t.Fatalf("ids = %v, want daily_today and three_day", ids)
	}
}

func TestEveningBatchIncludesTomorrow(t *testing.T) {
	location := mustLoadLocation(t)
	resolved, err := DefaultRegistry().BatchReports(Evening, ResolveRequest{
		Now:      mustParse("2026-05-29T18:00:00-05:00"),
		Location: location,
	})
	if err != nil {
		t.Fatalf("BatchReports() error = %v", err)
	}
	ids := resolvedIDs(resolved)
	if strings.Join(ids, ",") != "daily_tomorrow" {
		t.Fatalf("ids = %v, want daily_tomorrow", ids)
	}
}

func TestRegistryLookupErrorIsActionable(t *testing.T) {
	_, err := DefaultRegistry().Lookup(ID("unknown"))
	if err == nil {
		t.Fatal("Lookup() error = nil, want unknown report error")
	}
	if !strings.Contains(err.Error(), `unknown report "unknown"`) {
		t.Fatalf("error = %q, want unknown report context", err.Error())
	}
}

func TestRegistryDefinitionsHavePromptIDsAndComparisonStrategies(t *testing.T) {
	for _, definition := range DefaultRegistry().All() {
		if definition.PromptID == "" {
			t.Fatalf("%s PromptID is empty", definition.ID)
		}
		if definition.ComparisonStrategy == "" {
			t.Fatalf("%s ComparisonStrategy is empty", definition.ID)
		}
	}
}

func TestResolvedMetadata(t *testing.T) {
	location := mustLoadLocation(t)
	resolved, err := Resolve(DailyToday, ResolveRequest{Now: mustParse("2026-05-29T05:00:00-05:00"), Location: location})
	if err != nil {
		t.Fatalf("Resolve() error = %v", err)
	}
	metadata := resolved.Metadata()
	if metadata.ReportID != DailyToday {
		t.Fatalf("ReportID = %q, want daily_today", metadata.ReportID)
	}
	if metadata.PromptID != "weather.daily_report" {
		t.Fatalf("PromptID = %q, want weather.daily_report", metadata.PromptID)
	}
	if !strings.Contains(metadata.RunID, "daily_today") {
		t.Fatalf("RunID = %q, want report id", metadata.RunID)
	}
}

func assertPeriod(t *testing.T, period timeutil.Period, wantStart string, wantEnd string) {
	t.Helper()
	if !period.IsValid() {
		t.Fatalf("period = %#v, want valid", period)
	}
	if period.Start.Format(time.RFC3339) != wantStart {
		t.Fatalf("Start = %s, want %s", period.Start.Format(time.RFC3339), wantStart)
	}
	if period.End.Format(time.RFC3339) != wantEnd {
		t.Fatalf("End = %s, want %s", period.End.Format(time.RFC3339), wantEnd)
	}
}

func resolvedIDs(resolved []Resolved) []string {
	ids := make([]string, 0, len(resolved))
	for _, item := range resolved {
		ids = append(ids, string(item.Definition.ID))
	}
	return ids
}

func mustLoadLocation(t *testing.T) *time.Location {
	t.Helper()
	location, err := time.LoadLocation("America/Chicago")
	if err != nil {
		t.Fatalf("load location: %v", err)
	}
	return location
}

func mustParse(value string) time.Time {
	parsed, err := time.Parse(time.RFC3339, value)
	if err != nil {
		panic(err)
	}
	return parsed
}