package services

import (
	"testing"

	"github.com/breakpilot/school-service/internal/models"
)

func TestUpsertSchoolCalendarConfigRequest_Validation(t *testing.T) {
	tests := []struct {
		name    string
		req     models.UpsertSchoolCalendarConfigRequest
		wantErr bool
	}{
		{"valid NI", models.UpsertSchoolCalendarConfigRequest{Bundesland: "DE-NI"}, false},
		{"empty bundesland", models.UpsertSchoolCalendarConfigRequest{Bundesland: ""}, true},
		{"too long", models.UpsertSchoolCalendarConfigRequest{Bundesland: "DE-NIE"}, true},
		{"too short", models.UpsertSchoolCalendarConfigRequest{Bundesland: "DE"}, true},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if (validate.Struct(tt.req) != nil) != tt.wantErr {
				t.Errorf("unexpected validation outcome for %s", tt.name)
			}
		})
	}
}

func TestCreateSchoolEventRequest_Validation(t *testing.T) {
	tests := []struct {
		name    string
		req     models.CreateSchoolEventRequest
		wantErr bool
	}{
		{"valid fortbildung", models.CreateSchoolEventRequest{
			Title: "SCHILF", EventType: "fortbildung",
			StartDate: "2026-10-01", EndDate: "2026-10-01",
		}, false},
		{"missing title", models.CreateSchoolEventRequest{
			EventType: "fortbildung", StartDate: "2026-10-01", EndDate: "2026-10-01",
		}, true},
		{"invalid event type", models.CreateSchoolEventRequest{
			Title: "X", EventType: "wedding",
			StartDate: "2026-10-01", EndDate: "2026-10-01",
		}, true},
		{"missing dates", models.CreateSchoolEventRequest{
			Title: "X", EventType: "schulfeier",
		}, true},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if (validate.Struct(tt.req) != nil) != tt.wantErr {
				t.Errorf("unexpected validation outcome for %s", tt.name)
			}
		})
	}
}

func TestNewCalendarService_Constructs(t *testing.T) {
	s := NewCalendarService(nil)
	if s == nil {
		t.Fatal("expected non-nil service")
	}
}

func TestDefaultSchoolYearDates_FallbackFormat(t *testing.T) {
	// No override → deterministic YYYY-MM-DD strings with end > start.
	start, end := defaultSchoolYearDates(nil)
	if len(start) != 10 || len(end) != 10 {
		t.Fatalf("expected YYYY-MM-DD strings, got %q %q", start, end)
	}
	if end <= start {
		t.Errorf("end %q must be after start %q", end, start)
	}
}

func TestDefaultSchoolYearDates_ExplicitOverride(t *testing.T) {
	s, e := "2030-09-01", "2031-06-30"
	req := &models.SchoolYearRolloverRequest{NewYearStart: &s, NewYearEnd: &e}
	gotS, gotE := defaultSchoolYearDates(req)
	if gotS != s || gotE != e {
		t.Errorf("override ignored: got %q/%q want %q/%q", gotS, gotE, s, e)
	}
}

func TestParseClassIDs_AcceptsValidAndRejectsGarbage(t *testing.T) {
	good := []string{"00000000-0000-0000-0000-000000000001", "00000000-0000-0000-0000-000000000002"}
	out, err := parseClassIDs(good)
	if err != nil || len(out) != 2 {
		t.Fatalf("expected 2 parsed UUIDs, got %v err=%v", out, err)
	}

	if _, err := parseClassIDs([]string{"not-a-uuid"}); err == nil {
		t.Errorf("expected error for invalid uuid")
	}

	// Empty strings are silently dropped (curl convenience).
	out, err = parseClassIDs([]string{"", "00000000-0000-0000-0000-000000000003", ""})
	if err != nil || len(out) != 1 {
		t.Errorf("expected 1 parsed UUID, got %v err=%v", out, err)
	}
}