import { type Editor } from "../../main";
import { makeExampleFactory } from "../../Documentation";

// @ts-ignore
export const interaction = (application: Editor): string => {
  const makeExample = makeExampleFactory(application);
  return `
# Interaction

Topos can interact with the physical world or react to events coming from outside the system (_MIDI_, physical control, etc). By creating interactions with your mouse, keyboard or controllers, you can make your performance more dynamic and/or easier to control.


## MIDI input

Topos can use MIDI input to estimate the BPM from incoming Clock messages and to control sounds with incoming note and CC messages. Sending MIDI messages to Topos is like sending messages to a far away universe; you can't expect a quick response, but the messages will be received and processed eventually.

### Note Input

MIDI input can be enabled in the settings panel. Once you have done that, you can use the following functions to control values. All methods have channel parameter as optional value to receive only notes from a certain channel:
* <ic>active_notes(channel?: number)</ic>: returns array of the active notes / pressed keys as an array of MIDI note numbers (0-127). Returns undefined if no notes are active.

${makeExample(
  "Play active notes as chords",
  `
  beat(1) && active_notes() && sound('sine').chord(active_notes()).out()
  `,
  true,
)}

${makeExample(
  "Play active notes as arpeggios",
  `
  beat(0.25) && active_notes() && sound('juno').note(
    active_notes().beat(0.5)+[12,24].beat(0.25)
  ).cutoff(300 + usine(1/4) * 2000).out()
  `,
  false,
)}


* <ic>sticky_notes(channel?: number)</ic>: returns array of the last pressed keys as an array of MIDI note numbers (0-127). Notes are added and removed from the list with the "Note on"-event. Returns undefined if no keys have been pressed.

${makeExample(
  "Play continous arpeggio with sticky notes",
  `
  beat(0.25) && sticky_notes() && sound('arp')
  .note(sticky_notes().palindrome().beat(0.25)).out()
  `,
  true,
)}

* <ic>last_note(channel?: number)</ic>: returns the last note that has been received. Returns 60 if no other notes have been received.

${makeExample(
  "Play last note",
  `
  beat(0.5) && sound('sawtooth').note(last_note())
  .vib([1, 3, 5].beat(1))
  .vibmod([1,3,2,4].beat(2)).out()
  `,
  false,
)}

* <ic>buffer()</ic>: return true if there are notes in the buffer.
* <ic>buffer_note(channel?: number)</ic>: returns last unread note that has been received. Note is fetched and removed from start of the buffer once this is called. Returns undefined if no notes have been received.

${makeExample(
  "Play buffered note",
  `
  beat(1) && buffer() && sound('sine').note(buffer_note()).out()
  `,
  false,
)}




### MIDI CC Input

Midi CC messages can be used to control any value in Topos. MIDI input can be defined in Settings and last received CC message can be used to control any numeric value within Topos.

Currently supported methods for CC input are:
* <ic>last_cc(control: number, channel?: number)</ic>: Returns last received CC value for given control number (and optional channel). By default last CC value is last value from ANY channel or 64 if no CC messages have been received.

${makeExample(
  "Play notes with cc",
  `
  beat(0.5) && sound('arp').note(last_cc(74)).out()
  `,
  true,
)}

${makeExample(
  "Control everything with CCs",
  `
  beat(0.5) :: sound('sine')
  .freq(last_cc(75)*3)
  .cutoff(last_cc(76)*2*usine())
  .sustain(1.0)
  .out()

beat(last_cc(74)/127*.5) :: sound('sine')
  .freq(last_cc(75)*6)
  .cutoff(last_cc(76)*3*usine())
  .sustain(last_cc(74)/127*.25)
  .out()
  `,
  false,
)}


## Run scripts with MIDI

MIDI note messages with channels can also be used to trigger scripts.  This can be enabled in the settings panel by setting _Route channels to scripts_.

## MIDI clock Synchronisation

Topos can controlled from external hadware or software using MIDI clock messages. To enable this feature, you need to connect a MIDI input as Midi Clock in the settings panel. 
Once you have done that, Topos will listen to incoming Clock messages and will use them to estimate the current BPM. Topos will also listen to <ic>Start</ic>, <ic>Stop</ic> and <ic>Continue</ic> messages to start and stop the evaluation. 
Different MIDI devices can send clock at different resolution, define Clock PPQN in settings to match the resolution of your device. 

## Scale output for lighted keys

Topos can output scales to external keyboards lighted keys using the following functions:

- <ic>show_scale(key: string, scale: string|int, channel?: number, port?: string|number, soundOff?: boolean): void</ic>: sends the scale as midi on messages to specified port and channel to light the keys of external keyboard. If soundOff is true, all sound off message will be sent after every note on message. This can be useful with some keyboards not supporting external channel for lightning or routing for the midi in to suppress the sound from incoming note on messages.

${makeExample(
  "Show scale on external keyboard",
  `show_scale("F","aeolian",0,4)`,
  true,
)}

${makeExample("Hide scale", `hide_scale("F","aeolian",0,4)`, true)}


`;
};
