-- | Programming the Arduino with Copilot, in functional reactive style.
--
-- This module should work on any model of Arduino.
-- See Copilot.Arduino.Uno and Copilot.Arduino.Nano for model-specific code.
--
-- There are also libraries like Copilot.Arduino.Library.Serial to support
-- additional hardware.

{-# LANGUAGE RebindableSyntax #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE TypeApplications #-}

module Copilot.Arduino (
        -- * Arduino sketch generation
        arduino,
        Sketch,
        Pin,
        -- * Functional reactive programming
        Behavior,
        TypedBehavior,
        Event,
        (@:),
        -- * Inputs
        Input,
        input,
        input',
        pullup,
        millis,
        micros,
        -- * Outputs
        --
        -- | Only a few common outputs are included in this module.
        -- Import a module such as Copilot.Arduino.Uno for `Pin`
        -- definitions etc.
        Output,
        led,
        (=:),
        pwm,
        delay,
        -- * Other types
        ADC,
        MilliSeconds(..),
        MicroSeconds(..),
        ClockMillis,
        ClockMicros,
        -- * Utilities
        blinking,
        firstIteration,
        frequency,
        sketchSpec,
        -- * Copilot DSL
        --
        -- | The Copilot.Language module is re-exported here, including
        -- a version of the Prelude modified for it. You should enable
        -- the RebindableSyntax language extension in your program
        -- to use the Copilot DSL.
        --
        -- > {-# LANGUAGE RebindableSyntax #-}
        --
        -- For documentation on using the Copilot DSL, see
        -- <https://copilot-language.github.io/>
        Stream,
        module X,
) where

import Language.Copilot as X hiding (Stream)
import Language.Copilot (Stream)
import Copilot.Arduino.Internals
import Copilot.Arduino.Main
import Control.Monad.Writer
import Data.Proxy
import Data.Maybe
import qualified Data.Map as M
import qualified Data.Set as S

-- | Use this to make a LED blink on and off.
--
-- On each iteration of the `Sketch`, this changes to the opposite of its
-- previous value.
--
-- This is implemented using Copilot's `clk`, so to get other blinking
-- behaviors, just pick different numbers, or use Copilot `Stream`
-- combinators.
-- 
-- > blinking = clk (period 2) (phase 1)
blinking :: Behavior Bool
blinking = clk (period (2 :: Integer)) (phase (1 :: Integer))

-- | True on the first iteration of the `Sketch`, and False thereafter.
firstIteration :: Behavior Bool
firstIteration = [True]++false

-- | Use this to make an event occur 1 time out of n.
--
-- This is implemented using Copilot's `clk`:
--
-- > frequency = clk (period n) (phase 1)
frequency :: Integer -> Behavior Bool
frequency n = clk (period n) (phase 1)

-- | A stream of milliseconds.
data MilliSeconds = MilliSeconds (Stream Word32)

-- | A stream of microseconds.
data MicroSeconds = MicroSeconds (Stream Word32)

-- | Use this to add a delay between each iteration of the `Sketch`.
-- A `Sketch` with no delay will run as fast as the hardware can run it.
--
-- > delay := MilliSeconds (constant 100)
delay :: Delay
delay = Delay

data Delay = Delay

instance Output Delay MilliSeconds where
        Delay =: (MilliSeconds n) = tell
                [(trigger "delay" true [arg n], mempty)]

instance Output Delay MicroSeconds where
        Delay =: (MicroSeconds n) = tell
                [(trigger "delayMicroseconds" true [arg n], mempty)]

-- | Number of MillisSeconds since the Arduino booted.
--
-- > n <- input millis
-- 
-- The value wraps back to zero after approximately 50 days.
millis :: ClockMillis
millis = ClockMillis

-- | Number of MicroSeconds since the Arduino booted.
--
-- > n <- input micros
-- 
-- The value wraps back to zero after approximately 70 minutes.
micros :: ClockMicros
micros = ClockMicros

data ClockMillis = ClockMillis
data ClockMicros = ClockMicros

instance Input ClockMillis Word32 where
        input' ClockMillis = inputClock "millis"

instance Input ClockMicros Word32 where
        input' ClockMicros = inputClock "micros"

inputClock :: [Char] -> [Word32] -> Sketch (Behavior Word32)
inputClock src interpretvalues = mkInput $ InputSource
        { setupInput = []
        , defineVar = [CLine $ showCType (Proxy @Word32) <> " " <> varname <>";"]
        , inputPinmode = mempty
        , readInput = [CLine $ varname <> " = " <> src <> "();"]
        , inputStream = extern varname interpretvalues'
        }
  where
        varname = "clock_" <> src
        interpretvalues'
                | null interpretvalues = Nothing
                | otherwise = Just interpretvalues

-- | Use this to read a value from a component of the Arduino.
--
-- For example, to read a digital value from pin12 and turn on the 
-- led when the pin is high:
--
-- > buttonpressed <- input pin12
-- > led =: buttonpressed
--
-- Some pins support multiple types of reads, for example pin a0
-- supports a digital read (`Bool`), and an analog to digital converter
-- read (`ADC`). In such cases you may need to specify the type of
-- data to read:
--
-- > v <- input a0 :: Sketch (Behavior ADC)
input :: Input o t => o -> Sketch (Behavior t)
input o = input' o []

-- | Normally when a digital value is read from a `Pin`, it is configured
-- without the internal pullup resistor being enabled. Use this to enable
-- the pullup register for all reads from the `Pin`.
--
-- Bear in mind that enabling the pullup resistor inverts the value that
-- will be read from the pin.
--
-- > pullup pin12
pullup :: Pin t -> Sketch ()
pullup (Pin p) = tell [(return (), f)]
  where
        f = mempty
                { pinmodes = M.singleton p (S.singleton InputPullupMode)
                }

-- | Use this to do PWM output to a pin.
--
-- > pin3 =: pwm (constant 128)
-- 
-- Each Word8 of the Behavior describes a PWM square wave.
-- 0 is always off and 255 is always on.
pwm :: Behavior Word8 -> TypedBehavior 'PWM Word8
pwm = TypedBehavior

-- | The on-board LED.
led :: Pin '[ 'DigitalIO ]
led = Pin (PinId 13)

-- | Extracts a copilot `Spec` from a `Sketch`.
--
-- This can be useful to intergrate with other libraries 
-- such as copilot-theorem.
sketchSpec :: Sketch a -> Spec
sketchSpec = fromMaybe (return ()) . fst . evalSketch