package generatedtext

import (
	"strings"
	"testing"
)

func TestValidateTomorrowNormalizesJSON(t *testing.T) {
	value, normalized, err := ValidateTomorrow([]byte(`{
		"summary": " Storms become more likely tomorrow. ",
		"forecast_discussion": [
			"  A front will keep showers in the forecast. ",
			"",
			"  Temperatures stay seasonable by afternoon. "
		],
		"precipitation_timing": " Rain is most likely before sunrise. ",
		"confidence": " Medium "
	}`))
	if err != nil {
		t.Fatalf("ValidateTomorrow() error = %v", err)
	}
	if value.Summary != "Storms become more likely tomorrow." {
		t.Fatalf("Summary = %q, want trimmed summary", value.Summary)
	}
	if strings.Join(value.ForecastDiscussion, "|") != "A front will keep showers in the forecast.|Temperatures stay seasonable by afternoon." {
		t.Fatalf("ForecastDiscussion = %#v, want trimmed non-empty paragraphs", value.ForecastDiscussion)
	}
	if value.PrecipitationTiming != "Rain is most likely before sunrise." {
		t.Fatalf("PrecipitationTiming = %q, want trimmed precipitation timing", value.PrecipitationTiming)
	}
	want := `{"summary":"Storms become more likely tomorrow.","forecast_discussion":["A front will keep showers in the forecast.","Temperatures stay seasonable by afternoon."],"precipitation_timing":"Rain is most likely before sunrise.","confidence":"Medium"}`
	if string(normalized) != want {
		t.Fatalf("normalized = %s, want %s", normalized, want)
	}
}

func TestValidateTomorrowOmitsEmptyOptionalFields(t *testing.T) {
	_, normalized, err := ValidateTomorrow([]byte(`{
		"summary": "Storms become more likely tomorrow.",
		"forecast_discussion": ["A front will keep showers in the forecast."],
		"precipitation_timing": "   ",
		"confidence": "   "
	}`))
	if err != nil {
		t.Fatalf("ValidateTomorrow() error = %v", err)
	}
	want := `{"summary":"Storms become more likely tomorrow.","forecast_discussion":["A front will keep showers in the forecast."]}`
	if string(normalized) != want {
		t.Fatalf("normalized = %s, want %s", normalized, want)
	}
}

func TestValidateTomorrowRejectsInvalidInput(t *testing.T) {
	tests := []struct {
		name string
		in   string
		want string
	}{
		{
			name: "malformed",
			in:   `{`,
			want: "decode tomorrow generated text",
		},
		{
			name: "unknown field",
			in:   `{"summary":"Storms become more likely tomorrow.","forecast_discussion":["A front will keep showers in the forecast."],"extra":"value"}`,
			want: `unknown field "extra"`,
		},
		{
			name: "missing summary",
			in:   `{"forecast_discussion":["A front will keep showers in the forecast."]}`,
			want: "summary is required",
		},
		{
			name: "blank summary",
			in:   `{"summary":"  ","forecast_discussion":["A front will keep showers in the forecast."]}`,
			want: "summary is required",
		},
		{
			name: "missing forecast discussion",
			in:   `{"summary":"Storms become more likely tomorrow."}`,
			want: "forecast discussion is required",
		},
		{
			name: "blank forecast discussion",
			in:   `{"summary":"Storms become more likely tomorrow.","forecast_discussion":["  ",""]}`,
			want: "forecast discussion is required",
		},
		{
			name: "forecast discussion wrong type",
			in:   `{"summary":"Storms become more likely tomorrow.","forecast_discussion":"A front will keep showers in the forecast."}`,
			want: "cannot unmarshal string",
		},
		{
			name: "multiple values",
			in:   `{"summary":"Storms become more likely tomorrow.","forecast_discussion":["A front will keep showers in the forecast."]} {}`,
			want: "multiple JSON values",
		},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			_, _, err := ValidateTomorrow([]byte(test.in))
			if err == nil {
				t.Fatal("ValidateTomorrow() error = nil, want error")
			}
			if !strings.Contains(err.Error(), test.want) {
				t.Fatalf("ValidateTomorrow() error = %v, want %q", err, test.want)
			}
		})
	}
}