using DataConnection.DB.FoxPro;
using DataConnection.Interfaces;

namespace DataConnection.EF.SchemaProviders;

/// <summary>
/// Provider di schema per database Visual FoxPro / dBase, completamente managed
/// (legge i file <c>.dbf</c>/<c>.fpt</c>/<c>.dbc</c> senza provider OLE DB/ODBC).
/// La "connection string" è il percorso al <c>.dbc</c> o alla cartella di tabelle libere.
/// </summary>
public class FoxProSchemaProvider : IDatabaseSchemaProvider
{
    public Task<IDictionary<string, IEnumerable<DbColumnInfo>>> GetDatabaseSchemaAsync(string connectionString)
    {
        var info = FoxProReader.Resolve(connectionString);
        var result = new Dictionary<string, IEnumerable<DbColumnInfo>>(StringComparer.OrdinalIgnoreCase);

        foreach (var table in FoxProReader.GetTableNames(info))
        {
            try
            {
                var columns = FoxProReader.GetTableColumns(info, table);
                if (columns.Count > 0)
                    result[table] = columns;
            }
            catch (Exception ex)
            {
                // Una tabella corrotta/illeggibile non deve bloccare l'intera discovery.
                Console.WriteLine($"[FoxPro] Impossibile leggere lo schema della tabella {table}: {ex.Message}");
            }
        }

        return Task.FromResult<IDictionary<string, IEnumerable<DbColumnInfo>>>(result);
    }

    public Task<IEnumerable<string>> GetTableNamesAsync(string connectionString)
    {
        var info = FoxProReader.Resolve(connectionString);
        return Task.FromResult<IEnumerable<string>>(FoxProReader.GetTableNames(info));
    }

    public Task<IEnumerable<DbColumnInfo>> GetTableSchemaAsync(string connectionString, string tableName)
    {
        var info = FoxProReader.Resolve(connectionString);
        return Task.FromResult<IEnumerable<DbColumnInfo>>(FoxProReader.GetTableColumns(info, tableName));
    }

    public Task<IEnumerable<string>> GetAvailableDatabasesAsync(string connectionString)
    {
        // Sorgente file-based: un solo "database" (il container o la cartella).
        var info = FoxProReader.Resolve(connectionString);
        return Task.FromResult<IEnumerable<string>>(new[] { info.DisplayName });
    }
}