package generatedtext

import (
	"fmt"
	"strings"
	"testing"
)

func TestValidateDayStyleGeneratedTextSharedBehavior(t *testing.T) {
	reports := []struct {
		name     string
		validate func([]byte) (any, []byte, error)
	}{
		{
			name: "daily",
			validate: func(data []byte) (any, []byte, error) {
				value, normalized, err := ValidateDaily(data)
				return value, normalized, err
			},
		},
		{
			name: "today",
			validate: func(data []byte) (any, []byte, error) {
				value, normalized, err := ValidateToday(data)
				return value, normalized, err
			},
		},
		{
			name: "tomorrow",
			validate: func(data []byte) (any, []byte, error) {
				value, normalized, err := ValidateTomorrow(data)
				return value, normalized, err
			},
		},
	}

	for _, report := range reports {
		t.Run(report.name, func(t *testing.T) {
			t.Run("requires summary", func(t *testing.T) {
				_, _, err := report.validate([]byte(`{"forecast_discussion":["First paragraph."]}`))
				want := fmt.Sprintf("%s generated text summary is required", report.name)
				if err == nil || err.Error() != want {
					t.Fatalf("validate() error = %v, want %q", err, want)
				}
			})

			t.Run("requires non-empty forecast discussion", func(t *testing.T) {
				_, _, err := report.validate([]byte(`{"summary":"Shared summary.","forecast_discussion":["  ",""]}`))
				want := fmt.Sprintf("%s generated text forecast discussion is required", report.name)
				if err == nil || err.Error() != want {
					t.Fatalf("validate() error = %v, want %q", err, want)
				}
			})

			t.Run("trims and normalizes", func(t *testing.T) {
				value, normalized, err := report.validate([]byte(`{
					"summary": " Shared summary. ",
					"forecast_discussion": [
						" First paragraph. ",
						"",
						" Second paragraph. "
					],
					"precipitation_timing": " Afternoon. ",
					"confidence": " Medium "
				}`))
				if err != nil {
					t.Fatalf("validate() error = %v", err)
				}
				fields := dayStyleFieldsForTest(t, value)
				if fields.Summary != "Shared summary." {
					t.Fatalf("Summary = %q, want trimmed summary", fields.Summary)
				}
				if strings.Join(fields.ForecastDiscussion, "|") != "First paragraph.|Second paragraph." {
					t.Fatalf("ForecastDiscussion = %#v, want trimmed non-empty paragraphs", fields.ForecastDiscussion)
				}
				if fields.PrecipitationTiming != "Afternoon." {
					t.Fatalf("PrecipitationTiming = %q, want trimmed precipitation timing", fields.PrecipitationTiming)
				}
				if fields.Confidence != "Medium" {
					t.Fatalf("Confidence = %q, want trimmed confidence", fields.Confidence)
				}
				want := `{"summary":"Shared summary.","forecast_discussion":["First paragraph.","Second paragraph."],"precipitation_timing":"Afternoon.","confidence":"Medium"}`
				if string(normalized) != want {
					t.Fatalf("normalized = %s, want %s", normalized, want)
				}
			})

			t.Run("omits empty optional fields", func(t *testing.T) {
				_, normalized, err := report.validate([]byte(`{
					"summary": "Shared summary.",
					"forecast_discussion": ["First paragraph."],
					"precipitation_timing": "   ",
					"confidence": "   "
				}`))
				if err != nil {
					t.Fatalf("validate() error = %v", err)
				}
				want := `{"summary":"Shared summary.","forecast_discussion":["First paragraph."]}`
				if string(normalized) != want {
					t.Fatalf("normalized = %s, want %s", normalized, want)
				}
			})

			t.Run("rejects unknown fields", func(t *testing.T) {
				_, _, err := report.validate([]byte(`{"summary":"Shared summary.","forecast_discussion":["First paragraph."],"extra":"value"}`))
				if err == nil {
					t.Fatal("validate() error = nil, want error")
				}
				if !strings.Contains(err.Error(), `unknown field "extra"`) {
					t.Fatalf("validate() error = %v, want unknown field error", err)
				}
			})
		})
	}
}

func dayStyleFieldsForTest(t *testing.T, value any) dayStyleFields {
	t.Helper()

	switch value := value.(type) {
	case Daily:
		return (&value).dayStyleFields()
	case Today:
		return (&value).dayStyleFields()
	case Tomorrow:
		return (&value).dayStyleFields()
	default:
		t.Fatalf("value type = %T, want day-style generated text", value)
		return dayStyleFields{}
	}
}