package api

// schemagen_test.go generates and golden-compares JSON Schema files for every
// /api/X response type.
//
// Normal run (CI): go test ./internal/web/api/... — asserts schemas match committed files.
// Regenerate:      go test -run TestGenerateSchemas -update ./internal/web/api/...

import (
	"encoding/json"
	"flag"
	"os"
	"path/filepath"
	"testing"

	"github.com/invopop/jsonschema"
)

var updateFlag = flag.Bool("update", false, "overwrite api-schema fixture files with freshly generated schemas")

// JSONSchema makes Expected self-describing for the reflector at test time.
// The method is in a test file and is not compiled into production binaries.
// It emits oneOf [integer, "?"] to match the custom MarshalJSON behaviour.
func (Expected) JSONSchema() *jsonschema.Schema {
	return &jsonschema.Schema{
		OneOf: []*jsonschema.Schema{
			{Type: "integer"},
			{Enum: []any{"?"}},
		},
	}
}

func TestGenerateSchemas(t *testing.T) {
	r := &jsonschema.Reflector{
		AllowAdditionalProperties: false,
	}

	cases := []struct {
		name string
		val  any
	}{
		{"adults", &AdultsResponse{}},
		{"juniors", &JuniorsResponse{}},
		{"payments", &PaymentsResponse{}},
		{"version", &VersionResponse{}},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			schema := r.Reflect(tc.val)

			got, err := json.MarshalIndent(schema, "", "  ")
			if err != nil {
				t.Fatalf("marshal schema: %v", err)
			}
			got = append(got, '\n')

			// Path: go/internal/web/api/ → ../../.. → go/ → tests/fixtures/api-schema/
			path := filepath.Join("..", "..", "..", "tests", "fixtures", "api-schema", tc.name+".schema.json")

			if *updateFlag {
				if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
					t.Fatalf("mkdir: %v", err)
				}
				if err := os.WriteFile(path, got, 0o644); err != nil {
					t.Fatalf("write schema: %v", err)
				}
				t.Logf("wrote %s", path)
				return
			}

			want, err := os.ReadFile(path)
			if err != nil {
				t.Fatalf("read fixture %s: %v (re-run with -update to generate)", path, err)
			}
			if string(got) != string(want) {
				t.Errorf("schema mismatch for %s; re-run with -update to regenerate", tc.name)
			}
		})
	}
}