package spin:postgres@3.0.0;

interface postgres {
  /// Errors related to interacting with a database.
  variant error {
      connection-failed(string),
      bad-parameter(string),
      query-failed(string),
      value-conversion-failed(string),
      other(string)
  }

  /// Data types for a database column
  enum db-data-type {
      boolean,
      int8,
      int16,
      int32,
      int64,
      floating32,
      floating64,
      str,
      binary,
      date,
      time,
      datetime,
      timestamp,
      other,
  }

  /// Database values
  variant db-value {
      boolean(bool),
      int8(s8),
      int16(s16),
      int32(s32),
      int64(s64),
      floating32(float32),
      floating64(float64),
      str(string),
      binary(list<u8>),
      date(tuple<s32, u8, u8>), // (year, month, day)
      time(tuple<u8, u8, u8, u32>), // (hour, minute, second, nanosecond)
      /// Date-time types are always treated as UTC (without timezone info).
      /// The instant is represented as a (year, month, day, hour, minute, second, nanosecond) tuple.
      datetime(tuple<s32, u8, u8, u8, u8, u8, u32>),
      /// Unix timestamp (seconds since epoch)
      timestamp(s64),
      db-null,
      unsupported,
  }

  /// Values used in parameterized queries
  variant parameter-value {
      boolean(bool),
      int8(s8),
      int16(s16),
      int32(s32),
      int64(s64),
      floating32(float32),
      floating64(float64),
      str(string),
      binary(list<u8>),
      date(tuple<s32, u8, u8>), // (year, month, day)
      time(tuple<u8, u8, u8, u32>), // (hour, minute, second, nanosecond)
      /// Date-time types are always treated as UTC (without timezone info).
      /// The instant is represented as a (year, month, day, hour, minute, second, nanosecond) tuple.
      datetime(tuple<s32, u8, u8, u8, u8, u8, u32>),
      /// Unix timestamp (seconds since epoch)
      timestamp(s64),
      db-null,
  }

  /// A database column
  record column {
      name: string,
      data-type: db-data-type,
  }

  /// A database row
  type row = list<db-value>;

  /// A set of database rows
  record row-set {
      columns: list<column>,
      rows: list<row>,
  }

  /// A connection to a postgres database.
  resource connection {
    /// Open a connection to the Postgres instance at `address`.
    open: static func(address: string) -> result<connection, error>;

    /// Query the database.
    query: func(statement: string, params: list<parameter-value>) -> result<row-set, error>;

    /// Execute command to the database.
    execute: func(statement: string, params: list<parameter-value>) -> result<u64, error>;
  }
}