module MidiMelody
    exposing
        ( MidiInstruction(..)
        , MidiMelody
        , MidiNote
        , MidiBar
        )

{-| Data structures for describing an ABC melody  (i.e just a succession of notes and durations)

# Definition

# Data Types
@docs MidiInstruction, MidiMelody, MidiNote, MidiBar

-}

import Abc.ParseTree exposing (PitchClass, Accidental, KeySet, Repeat)
import Music.Notation exposing (NoteTime, MidiPitch, MidiTick)
import Music.Accidentals exposing (Accidentals)
import RepeatTypes exposing (GeneralisedBar)


{-| an individual Note (no pitch class implies a rest)
-}
type alias MidiNote =
    { ticks : MidiTick
    , pitch : MidiPitch
    , pc : Maybe PitchClass
    , accidental : Maybe Accidental
    }


{-| a Midi Instruction (not, chord or tempo)
-}
type MidiInstruction
    = MNote MidiNote Bool
      -- Bool indicates whether note is tied
    | MChord (List MidiNote)
    | MTempo Int



-- Tempo in microseconds per unit beat - we wrap this up in a bar of its own


{-| A Bar
-}
type alias MidiBar =
    GeneralisedBar MidiInstruction



{- GeneralisedBar is a parameterised type defined in RepeatTypes.elm
      which makes MidiBar (when expanded) look like this:
   type alias MidiBar =
     {  number : Int               -- sequential from zero
     ,  repeat : Maybe Repeat      -- the bar owns a repeat of some kind
     ,  iteration : Maybe Int      -- the bar has an iteration marker  (|1  or |2 etc)
     ,  accidentals : Accidentals  -- any notes marked explicitly as accidentals in the bar (updated in sequence)
     ,  notes : List MidiNote      -- the notes in the bar
     }
-}
{- the overall melody -}


type alias MidiMelody =
    List MidiBar