package test

import (
	"RenewCMS/internal/infrastructure/config"
	"os"
	"strings"
	"testing"
)

const maxSourceEnv = "IMAGE_VARIANT_MAX_SOURCE_BYTES"

func readRepositoryFile(t *testing.T, relative string) string {
	t.Helper()
	content, err := os.ReadFile("../" + relative)
	if err != nil {
		t.Fatalf("cannot read %s: %v", relative, err)
	}
	return string(content)
}

func between(source string, opening string, closing string) string {
	start := strings.Index(source, opening)
	if start < 0 {
		return ""
	}
	rest := source[start+len(opening):]
	end := strings.Index(rest, closing)
	if end < 0 {
		return rest
	}
	return rest[:end]
}

func TestImageVariantMaxSourceBytesSetting(t *testing.T) {
	rows := []struct {
		value   string
		unset   bool
		want    int64
		failure bool
	}{
		{unset: true, want: 10485760},
		{value: "2048", want: 2048},
		{value: "1", want: 1},
		{value: "0", failure: true},
		{value: "-5", failure: true},
		{value: "many", failure: true},
		{value: "1.5", failure: true},
	}
	for _, row := range rows {
		name := row.value
		if row.unset {
			name = "unset"
		}
		t.Run("The env var is loaded: "+name, func(t *testing.T) {
			setBaseSettingsEnv(t)
			if row.unset {
				t.Setenv(maxSourceEnv, "")
			} else {
				t.Setenv(maxSourceEnv, row.value)
			}

			settings, err := config.NewSettingsFromEnv()

			if row.failure {
				if err == nil || !strings.Contains(err.Error(), maxSourceEnv) {
					t.Errorf("err = %v", err)
				}
				return
			}
			if err != nil || settings.ImageVariantMaxSourceBytes != row.want {
				t.Errorf("value = %d, err = %v", settings.ImageVariantMaxSourceBytes, err)
			}
		})
	}
}

func TestImageVariantMaxSourceBytesDocumentation(t *testing.T) {
	t.Run("The default is listed in envDefaults and not in requiredEnvVars", func(t *testing.T) {
		main := readRepositoryFile(t, "cmd/server/main.go")

		defaults := between(main, "var envDefaults = map[string]string{", "\n}")
		required := between(main, "var requiredEnvVars = []string{", "\n}")

		if !strings.Contains(defaults, "config.EnvImageVariantMaxSourceBytes") || strings.Contains(required, "ImageVariant") || strings.Contains(required, maxSourceEnv) {
			t.Error("the default is misplaced")
		}
	})

	t.Run("The constant name and default are the documented ones", func(t *testing.T) {
		if config.EnvImageVariantMaxSourceBytes != maxSourceEnv || config.DefaultImageVariantMaxSourceBytes != "10485760" {
			t.Errorf("constants = %q %q", config.EnvImageVariantMaxSourceBytes, config.DefaultImageVariantMaxSourceBytes)
		}
	})

	for _, document := range []string{".env.example", "docs/configuration.md"} {
		t.Run("The env var is documented in "+document, func(t *testing.T) {
			if !strings.Contains(readRepositoryFile(t, document), maxSourceEnv) {
				t.Errorf("%s does not mention %s", document, maxSourceEnv)
			}
		})
	}
}