using Backend.Interface;
using Npgsql;
using NpgsqlTypes;

namespace Backend.DatabaseHandler
{
	public sealed class PostgresAnnotationStore : IAnnotationStore
	{
		private readonly string _connectionString;

		public PostgresAnnotationStore(IConfiguration configuration)
		{
			_connectionString = configuration.GetConnectionString("MarketDataDb")
				?? throw new InvalidOperationException("Missing connection string: MarketDataDb");
		}

		public async Task<string?> GetAsync(
			string user,
			string symbol,
			CancellationToken cancellationToken = default)
		{
			await using var conn = new NpgsqlConnection(_connectionString);
			await conn.OpenAsync(cancellationToken);

			const string sql = """
				SELECT annotations
				FROM chart_annotations
				WHERE username = @user AND symbol = @symbol;
				""";

			await using var cmd = new NpgsqlCommand(sql, conn);
			cmd.Parameters.AddWithValue("user", user);
			cmd.Parameters.AddWithValue("symbol", symbol);

			var result = await cmd.ExecuteScalarAsync(cancellationToken);
			return result as string;
		}

		public async Task UpsertAsync(
			string user,
			string symbol,
			string annotationsJson,
			CancellationToken cancellationToken = default)
		{
			await using var conn = new NpgsqlConnection(_connectionString);
			await conn.OpenAsync(cancellationToken);

			const string sql = """
				INSERT INTO chart_annotations (username, symbol, annotations)
				VALUES (@user, @symbol, @annotations)
				ON CONFLICT (username, symbol)
				DO UPDATE SET annotations = @annotations;
				""";

			await using var cmd = new NpgsqlCommand(sql, conn);
			cmd.Parameters.AddWithValue("user", user);
			cmd.Parameters.AddWithValue("symbol", symbol);
			cmd.Parameters.Add(new NpgsqlParameter("annotations", NpgsqlDbType.Jsonb) { Value = annotationsJson });

			await cmd.ExecuteNonQueryAsync(cancellationToken);
		}

		public async Task DeleteAsync(
			string user,
			string symbol,
			CancellationToken cancellationToken = default)
		{
			await using var conn = new NpgsqlConnection(_connectionString);
			await conn.OpenAsync(cancellationToken);

			const string sql = """
				DELETE FROM chart_annotations
				WHERE username = @user AND symbol = @symbol;
				""";

			await using var cmd = new NpgsqlCommand(sql, conn);
			cmd.Parameters.AddWithValue("user", user);
			cmd.Parameters.AddWithValue("symbol", symbol);

			await cmd.ExecuteNonQueryAsync(cancellationToken);
		}
	}
}