77 lines
1.3 KiB
Go
77 lines
1.3 KiB
Go
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package pdf417
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import (
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"errors"
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"math/big"
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"github.com/boombuler/barcode/utils"
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)
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type numberEncoder struct{}
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func newNumberEncoder() *numberEncoder {
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return new(numberEncoder)
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}
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func (encoder numberEncoder) CanEncode(char rune) bool {
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return utils.RuneToInt(char) != -1
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}
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func (encoder numberEncoder) GetSwitchCode(data string) int {
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return switchCodeNumber
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}
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func (encoder numberEncoder) Encode(digits string) ([]int, error) {
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digitCount := len(digits)
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chunkCount := digitCount / 44
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if digitCount%44 != 0 {
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chunkCount++
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}
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codeWords := []int{}
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for i := 0; i < chunkCount; i++ {
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start := i * 44
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end := start + 44
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if end > digitCount {
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end = digitCount
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}
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chunk := digits[start:end]
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cws, err := encodeChunk(chunk)
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if err != nil {
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return codeWords, err
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}
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codeWords = append(codeWords, cws...)
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}
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return codeWords, nil
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}
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func encodeChunk(chunkInput string) ([]int, error) {
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chunk := big.NewInt(0)
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_, ok := chunk.SetString("1"+chunkInput, 10)
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if !ok {
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return nil, errors.New("Failed converting")
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}
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cws := []int{}
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for chunk.Cmp(big.NewInt(0)) > 0 {
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newChunk, cw := chunk.DivMod(
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chunk,
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big.NewInt(900),
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big.NewInt(0),
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)
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chunk = newChunk
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cws = append([]int{int(cw.Int64())}, cws...)
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}
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return cws, nil
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}
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