class BytebeatProcessor extends AudioWorkletProcessor {
  constructor() {
    super()

    this.t = 0
    this.a = 8
    this.b = 16
    this.c = 32
    this.d = 64
    this.formula = null
    this.compiledFormula = null
    this.sampleRate = 8000
    this.duration = 4
    this.loopLength = this.sampleRate * this.duration
    this.playbackRate = 1.0
    this.error = false

    this.port.onmessage = (event) => {
      const { type, value } = event.data
      switch (type) {
        case 'formula':
          this.setFormula(value)
          break
        case 'variables':
          this.a = value.a ?? this.a
          this.b = value.b ?? this.b
          this.c = value.c ?? this.c
          this.d = value.d ?? this.d
          break
        case 'reset':
          this.t = 0
          break
        case 'loopLength':
          this.loopLength = value
          break
        case 'playbackRate':
          this.playbackRate = value
          break
      }
    }
  }

  setFormula(formulaString) {
    try {
      this.compiledFormula = new Function('t', 'a', 'b', 'c', 'd', `return ${formulaString}`)
      this.formula = formulaString
      this.error = false
    } catch (e) {
      console.error('Failed to compile bytebeat formula:', e)
      this.error = true
      this.compiledFormula = null
    }
  }

  process(inputs, outputs) {
    const output = outputs[0]

    if (output.length > 0) {
      const outputChannel = output[0]

      for (let i = 0; i < outputChannel.length; i++) {
        if (!this.compiledFormula || this.error) {
          outputChannel[i] = 0
        } else {
          try {
            const value = this.compiledFormula(this.t, this.a, this.b, this.c, this.d)
            const byteValue = value & 0xFF
            outputChannel[i] = (byteValue - 128) / 128
          } catch (e) {
            outputChannel[i] = 0
            if (!this.error) {
              console.error('Bytebeat runtime error:', e)
              this.error = true
            }
          }
        }

        this.t += this.playbackRate
        if (this.loopLength > 0 && this.t >= this.loopLength) {
          this.t = 0
        }
      }
    }

    return true
  }
}

registerProcessor('bytebeat-processor', BytebeatProcessor)