efritz/ij

package command

import "io"

type (
    Builder struct {
        prelude  []string
        options  []string
        args     []string
        stdin    io.ReadCloser
        builders []BuildFunc
    }

    BuildFunc func(b *Builder) error
)

func NewBuilder(prelude []string, builders []BuildFunc) *Builder {
    return &Builder{
        prelude:  prelude,
        builders: builders,
    }
}

func (b *Builder) Build() ([]string, io.ReadCloser, error) {
    for _, builder := range b.builders {
        if err := builder(b); err != nil {
            return nil, nil, err
        }
    }

    return append(b.prelude, append(b.options, b.args...)...), b.stdin, nil
}

func (b *Builder) AddArgs(args ...string) {
    b.args = append(b.args, args...)
}

func (b *Builder) AddFlag(flag string) {
    b.options = append(b.options, flag)
}

func (b *Builder) AddFlagValue(flag, value string) {
    if value != "" {
        b.options = append(b.options, flag, value)
    }
}

func (b *Builder) SetStdin(rc io.ReadCloser) {
    b.stdin = rc
}