abp/framework/src/Volo.Abp.Emailing/Volo/Abp/Emailing/Templates/EmailTemplateProvider.cs

using System;
using System.Globalization;
using System.Threading.Tasks;
using Microsoft.Extensions.Localization;
using Microsoft.Extensions.Options;
using Volo.Abp.DependencyInjection;
using Volo.Abp.Localization;

namespace Volo.Abp.Emailing.Templates
{
    public class EmailTemplateProvider : IEmailTemplateProvider, ITransientDependency
    {
        protected IEmailTemplateDefinitionManager EmailTemplateDefinitionManager;
        protected ITemplateLocalizer TemplateLocalizer { get; }
        protected EmailTemplateOptions Options { get; }
        protected IStringLocalizerFactory StringLocalizerFactory;

        public EmailTemplateProvider(IEmailTemplateDefinitionManager emailTemplateDefinitionManager,
            ITemplateLocalizer templateLocalizer, IStringLocalizerFactory stringLocalizerFactory,
            IOptions<EmailTemplateOptions> options)
        {
            EmailTemplateDefinitionManager = emailTemplateDefinitionManager;
            TemplateLocalizer = templateLocalizer;
            StringLocalizerFactory = stringLocalizerFactory;
            Options = options.Value;
        }

        public async Task<EmailTemplate> GetAsync(string name, string cultureName)
        {
            return await GetInternalAsync(name, cultureName);
        }

        protected virtual async Task<EmailTemplate> GetInternalAsync(string name, string cultureName)
        {
            var emailTemplateDefinition = EmailTemplateDefinitionManager.GetOrNull(name);
            if (emailTemplateDefinition == null)
            {
                // TODO: Localized message
                throw new AbpException("email template name not definition");
            }

            var emailTemplateString = emailTemplateDefinition.Contributors.GetOrNull(cultureName);
            if (emailTemplateString == null && emailTemplateDefinition.DefaultCultureName != null)
            {
                emailTemplateString =
                    emailTemplateDefinition.Contributors.GetOrNull(emailTemplateDefinition.DefaultCultureName);
                if (emailTemplateString != null)
                {
                    cultureName = emailTemplateDefinition.DefaultCultureName;
                }
            }

            if (emailTemplateString != null)
            {
                var emailTemplate = new EmailTemplate(emailTemplateString, emailTemplateDefinition);

                await SetLayoutAsync(emailTemplateDefinition, emailTemplate, cultureName);
                await LocalizeAsync(emailTemplateDefinition, emailTemplate, cultureName);

                return emailTemplate;
            }

            // TODO: Localized message
            throw new AbpException($"{cultureName} template not exist!");
        }

        protected virtual async Task SetLayoutAsync(EmailTemplateDefinition emailTemplateDefinition,
            EmailTemplate emailTemplate, string cultureName)
        {
            var layout = emailTemplateDefinition.Layout;
            if (layout.IsNullOrWhiteSpace())
            {
                return;
            }

            if (layout == EmailTemplateDefinition.DefaultLayoutPlaceHolder)
            {
                layout = Options.DefaultLayout;
            }

            var layoutTemplate = await GetInternalAsync(layout, cultureName);

            emailTemplate.SetLayout(layoutTemplate);
        }

        protected virtual Task LocalizeAsync(EmailTemplateDefinition emailTemplateDefinition,
            EmailTemplate emailTemplate, string cultureName)
        {
            if (emailTemplateDefinition.LocalizationResource == null)
            {
                return Task.CompletedTask;
            }

            var localizer = StringLocalizerFactory.Create(emailTemplateDefinition.LocalizationResource);

            emailTemplate.SetContent(
                TemplateLocalizer.Localize(localizer.WithCulture(new CultureInfo(cultureName)), emailTemplate.Content)
            );

            return Task.CompletedTask;
        }
    }
}