using System;
using System.Collections.Generic;
using System.IO;
using Newtonsoft.Json;
using Serilog;
using SyncEngine.Configuration;

namespace SyncEngine.Access
{
    /// <summary>
    /// Fallback: view SQL exported manually from Access into config/access-views.json.
    /// </summary>
    internal sealed class AccessViewConfigLoader
    {
        private readonly SyncOptions _options;
        private readonly ILogger _logger;

        public AccessViewConfigLoader(SyncOptions options, ILogger logger)
        {
            _options = options;
            _logger = logger;
        }

        public bool TryLoadQueries(IList<AccessQuerySchema> queries)
        {
            var path = Path.Combine(_options.ConfigDirectory, "access-views.json");
            if (!File.Exists(path))
            {
                return false;
            }

            try
            {
                var map = JsonConvert.DeserializeObject<Dictionary<string, string>>(File.ReadAllText(path));
                if (map == null || map.Count == 0)
                {
                    return false;
                }

                foreach (var entry in map)
                {
                    var query = new AccessQuerySchema { Name = entry.Key, SqlText = entry.Value ?? "" };
                    AccessSchemaReader.ClassifyQuery(query);
                    queries.Add(query);
                }

                _logger.Information(
                    "Loaded {Count} Access queries from {Path} ({Provision} marked for SQL Server views)",
                    queries.Count,
                    path,
                    CountProvisionable(queries));

                return queries.Count > 0;
            }
            catch (Exception ex)
            {
                _logger.Warning("Could not load {Path} ({Message})", path, ex.Message);
                return false;
            }
        }

        private static int CountProvisionable(IList<AccessQuerySchema> queries)
        {
            var count = 0;
            foreach (var query in queries)
            {
                if (query.ShouldProvision)
                {
                    count++;
                }
            }

            return count;
        }
    }
}