package audio

import "math"

var _ Buffer = (*IntBuffer)(nil)

type IntBuffer struct {
    Format         *Format
    Data           []int
    SourceBitDepth int
}

func (buf *IntBuffer) PCMFormat() *Format {
    return buf.Format
}

func (buf *IntBuffer) AsFloatBuffer() *FloatBuffer {
    newB := &FloatBuffer{}
    newB.Data = make([]float64, len(buf.Data))
    for i := 0; i < len(buf.Data); i++ {
        newB.Data[i] = float64(buf.Data[i])
    }
    newB.Format = &Format{
        NumChannels: buf.Format.NumChannels,
        SampleRate:  buf.Format.SampleRate,
    }
    return newB
}

func (buf *IntBuffer) AsFloat32Buffer() *Float32Buffer {
    newB := &Float32Buffer{}
    newB.Data = make([]float32, len(buf.Data))
    max := int64(0)
    if buf.SourceBitDepth == 0 {
        for _, s := range buf.Data {
            if int64(s) > max {
                max = int64(s)
            }
        }
        buf.SourceBitDepth = 8
        if max > 127 {
            buf.SourceBitDepth = 16
        }
        if max > 32767 {
            buf.SourceBitDepth = 24
        }
        if max > 8388607 {
            buf.SourceBitDepth = 32
        }
        if max > 4294967295 {
            buf.SourceBitDepth = 64
        }
    }
    newB.SourceBitDepth = buf.SourceBitDepth
    factor := math.Pow(2, float64(buf.SourceBitDepth)-1)
    for i := 0; i < len(buf.Data); i++ {
        newB.Data[i] = float32(float64(buf.Data[i]) / factor)
    }
    newB.Format = &Format{
        NumChannels: buf.Format.NumChannels,
        SampleRate:  buf.Format.SampleRate,
    }
    return newB
}

func (buf *IntBuffer) AsIntBuffer() *IntBuffer {
    return buf
}

func (buf *IntBuffer) NumFrames() int {
    if buf == nil || buf.Format == nil {
        return 0
    }
    numChannels := buf.Format.NumChannels
    if numChannels == 0 {
        numChannels = 1
    }
    return len(buf.Data) / numChannels
}

func (buf *IntBuffer) Clone() Buffer {
    if buf == nil {
        return nil
    }
    newB := &IntBuffer{}
    newB.Data = make([]int, len(buf.Data))
    copy(newB.Data, buf.Data)
    newB.Format = &Format{
        NumChannels: buf.Format.NumChannels,
        SampleRate:  buf.Format.SampleRate,
    }
    return newB
}