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// Contains implementations of ExecWrapper interfaces that runs live commands
package execwrapper

import (
	"context"
	"io"
	"os/exec"
)

// RealExecWrapper is an implementation of ExecWrapper that uses the os/exec package
type RealExecWrapper struct{}

func CreateRealExecWrapper() RealExecWrapper {
	return RealExecWrapper{}
}

func (e RealExecWrapper) Command(name string, args ...string) CmdWrapper {
	return &RealCmdWrapper{cmd: exec.Command(name, args...)}
}

func (e RealExecWrapper) CommandContext(ctx context.Context, name string, args ...string) CmdWrapper {
	return &RealCmdWrapper{cmd: exec.CommandContext(ctx, name, args...)}
}

// RealCmdWrapper is an implementation of CmdWrapper that wraps live exec.Cmd instances.
type RealCmdWrapper struct {
	cmd    *exec.Cmd
	stdout io.Writer
	stderr io.Writer
}

func (e *RealCmdWrapper) WithStdout(stdout io.Writer) CmdWrapper {
	return &RealCmdWrapper{
		cmd:    e.cmd,
		stdout: stdout,
		stderr: e.stderr,
	}
}

func (e *RealCmdWrapper) WithStderr(stderr io.Writer) CmdWrapper {
	return &RealCmdWrapper{
		cmd:    e.cmd,
		stdout: e.stdout,
		stderr: stderr,
	}
}

func (e *RealCmdWrapper) Run() error {
	e.cmd.Stdout = e.stdout
	e.cmd.Stderr = e.stderr
	return e.cmd.Run()
}

func (e *RealCmdWrapper) RunWithCombinedOutput() ([]byte, error) {
	if e.stdout != nil || e.stderr != nil {
		return nil, ErrCombinedOutputWithWriters
	}
	return e.cmd.CombinedOutput()
}