package bit

import (
    "bytes"
    "fmt"
    "io"
    "log"
)

func ExampleWriter_WriteBits() {
    var buf bytes.Buffer
    bw := NewWriter(&buf, MSB)
    bw.WriteBits(0x0f, 4) // Writes 1111
    bw.WriteBits(0x00, 1) //        0
    bw.WriteBits(0x13, 5) //        1001 1
    // Close will flush with zero bits, in this case
    //                              0000 00
    if err := bw.Close(); err != nil {
        log.Fatal(err)
    }
    fmt.Printf("%08b", buf.Bytes())
    // Output:
    // [11110100 11000000]
}

func Example() {
    const message = "This is a test."
    fmt.Printf("%q as bytes: % 02[1]X\n", message, []byte(message))
    fmt.Printf("    original bits: %08b\n", []byte(message))

    // Re-write in 7 bit chunks to buf:
    var buf bytes.Buffer
    bw := NewWriter(&buf, MSB)
    for _, r := range message {
        bw.WriteBits(uint16(r), 7) // nolint: errcheck
    }
    if err := bw.Close(); err != nil {
        log.Fatal(err)
    }
    fmt.Printf("Written bitstream: %08b\n", buf.Bytes())
    fmt.Printf("Written bytes: % 02X\n", buf.Bytes())

    // Read back in 7 bit chunks:
    br := NewReader(&buf, MSB)
    var result []byte
    for {
        v, err := br.ReadBits(7)
        if err != nil {
            if err != io.EOF {
                log.Fatal(err)
            }
            break
        }
        if v != 0 {
            result = append(result, byte(v))
        }
    }
    fmt.Printf("Read back as \"%s\"\n", result)
    // Output:
    // "This is a test." as bytes: 54 68 69 73 20 69 73 20 61 20 74 65 73 74 2E
    //     original bits: [01010100 01101000 01101001 01110011 00100000 01101001 01110011 00100000 01100001 00100000 01110100 01100101 01110011 01110100 00101110]
    // Written bitstream: [10101001 10100011 01001111 00110100 00011010 01111001 10100000 11000010 10000011 10100110 01011110 01111101 00010111 00000000]
    // Written bytes: A9 A3 4F 34 1A 79 A0 C2 83 A6 5E 7D 17 00
    // Read back as "This is a test."
}