#!/usr/bin/env python
import argparse
import csv
import sys

parser = argparse.ArgumentParser()
parser.add_argument("input", nargs="+", help="input CSV (pitch, duration, pause)")
parser.add_argument("-o", "--output", default="/dev/stdout", help="output file (gcode)")
parser.add_argument(
    "--steps-per-mm",
    default=5,
    type=float,
    help="motor steps per mm (actually an arbitrary scaling factor)",
)
parser.add_argument("--bpm", default=60, type=float, help="beats per minute")
args = parser.parse_args()

# starting from C3 = 130.81 Hz
pitches = ["c", "c#", "d", "d#", "e", "f", "f#", "g", "g#", "a", "a#", "b"]
frequencies = {
    f"{pitches[i % 12]}{i // 12 + 3}": 2 ** (i / 12) * 130.81 for i in range(36)
}
# duration of 1/16th beat
base_duration = 60 / args.bpm / 16

with open(args.output, "w") as f:
    f.write("G21 ; set units to millimeters\n")
    f.write("G90 ; use absolute coordinates\n")
    f.write("G0 Z10 F300\n")
    f.write("G0 X0 Y0 F3000\n")
    f.write("G4 S2 ; wait 2 seconds\n")
    position = 0
    for filename in args.input:
        with open(filename, "r") as notes:
            for pitch, duration, pause in csv.reader(notes):
                if pitch == "":
                    # skip comment
                    continue
                try:
                    frequency = frequencies[pitch]
                except KeyError:
                    sys.exit("pitch goes from c3 to b5")
                duration = int(duration)
                pause = int(pause)
                if duration < 1 or pause < 0:
                    sys.exit("duration/pause are integer multiples of 1/16th beat")
                feedrate = int(frequency * 60 / args.steps_per_mm)
                length = duration * base_duration / 60 * feedrate
                position += -length if position > 100 else length
                if position < 0 or position > 200:
                    sys.exit("does not fit in 200x200")
                pause_ms = int(pause * base_duration)
                f.write(f"G0 X{position:.6f} Y{position:.6f} F{feedrate}\n")
                f.write(f"G4 P{pause_ms}\n")
        f.write("G4 S2 ; wait 2 seconds\n")