// ==========================================================================
//  Squidex Headless CMS
// ==========================================================================
//  Copyright (c) Squidex UG (haftungsbeschraenkt)
//  All rights reserved. Licensed under the MIT license.
// ==========================================================================

using Squidex.Domain.Apps.Core.Scripting;

namespace Squidex.Domain.Apps.Entities.Contents.Queries.Steps
{
    public sealed class ScriptContent : IContentEnricherStep
    {
        private readonly IScriptEngine scriptEngine;

        public ScriptContent(IScriptEngine scriptEngine)
        {
            this.scriptEngine = scriptEngine;
        }

        public async Task EnrichAsync(Context context, IEnumerable<ContentEntity> contents, ProvideSchema schemas,
            CancellationToken ct)
        {
            if (!ShouldEnrich(context))
            {
                return;
            }

            foreach (var group in contents.GroupBy(x => x.SchemaId.Id))
            {
                var (schema, _) = await schemas(group.Key);

                var script = schema.SchemaDef.Scripts.Query;

                if (string.IsNullOrWhiteSpace(script))
                {
                    continue;
                }

                var vars = new ContentScriptVars
                {
                    AppId = schema.AppId.Id,
                    AppName = schema.AppId.Name,
                    SchemaId = schema.Id,
                    SchemaName = schema.SchemaDef.Name,
                    User = context.User
                };

                var preScript = schema.SchemaDef.Scripts.QueryPre;

                if (!string.IsNullOrWhiteSpace(preScript))
                {
                    var options = new ScriptOptions
                    {
                        AsContext = true
                    };

                    await scriptEngine.ExecuteAsync(vars, preScript, options, ct);
                }

                foreach (var content in group)
                {
                    await TransformAsync(vars, script, content, ct);
                }
            }
        }

        private async Task TransformAsync(ContentScriptVars sharedVars, string script, ContentEntity content,
            CancellationToken ct)
        {
            var vars = new ContentScriptVars
            {
                ContentId = content.Id,
                Data = content.Data,
                DataOld = default,
                Status = content.Status,
                StatusOld = default
            };

            foreach (var (key, value) in sharedVars)
            {
                if (!vars.ContainsKey(key))
                {
                    vars[key] = value;
                }
            }

            var options = new ScriptOptions
            {
                AsContext = true
            };

            content.Data = await scriptEngine.TransformAsync(vars, script, options, ct);
        }

        private static bool ShouldEnrich(Context context)
        {
            return !context.IsFrontendClient;
        }
    }
}