package config

import (
	"fmt"
	"strconv"
)

const (
	EnvImageVariantMaxSourceBytes     = "IMAGE_VARIANT_MAX_SOURCE_BYTES"
	DefaultImageVariantMaxSourceBytes = "10485760"

	EnvImageVariantMaxSourcePixels     = "IMAGE_VARIANT_MAX_SOURCE_PIXELS"
	DefaultImageVariantMaxSourcePixels = "50000000"

	EnvImageVariantMaxConcurrentRenders     = "IMAGE_VARIANT_MAX_CONCURRENT_RENDERS"
	DefaultImageVariantMaxConcurrentRenders = "4"
)

func imageVariantMaxSourceBytesFromEnv() (int64, error) {
	raw := envOrDefault(EnvImageVariantMaxSourceBytes, DefaultImageVariantMaxSourceBytes)
	value, err := strconv.ParseInt(raw, 10, 64)
	if err != nil || value < 1 {
		return 0, fmt.Errorf("%s must be a whole number of bytes greater than zero, got %q", EnvImageVariantMaxSourceBytes, raw)
	}
	return value, nil
}

func imageVariantMaxSourcePixelsFromEnv() (int64, error) {
	raw := envOrDefault(EnvImageVariantMaxSourcePixels, DefaultImageVariantMaxSourcePixels)
	value, err := strconv.ParseInt(raw, 10, 64)
	if err != nil || value < 1 {
		return 0, fmt.Errorf("%s must be a whole number of pixels greater than zero, got %q", EnvImageVariantMaxSourcePixels, raw)
	}
	return value, nil
}

func imageVariantMaxConcurrentRendersFromEnv() (int, error) {
	raw := envOrDefault(EnvImageVariantMaxConcurrentRenders, DefaultImageVariantMaxConcurrentRenders)
	value, err := strconv.Atoi(raw)
	if err != nil || value < 1 {
		return 0, fmt.Errorf("%s must be a whole number of renders greater than zero, got %q", EnvImageVariantMaxConcurrentRenders, raw)
	}
	return value, nil
}