package oscommands

import (
	"os"
	"os/exec"
	"strings"

	"github.com/mgutz/str"
)

type ICmdObjBuilder interface {
	// New returns a new command object based on the string provided
	New(cmdStr string) ICmdObj
	// NewShell takes a string like `git commit` and returns an executable shell command for it e.g. `sh -c 'git commit'`
	NewShell(commandStr string) ICmdObj
	// NewFromArgs takes a slice of strings like []string{"git", "commit"} and returns a new command object. This can be useful when you don't want to worry about whitespace and quoting and stuff.
	NewFromArgs(args []string) ICmdObj
	// Quote wraps a string in quotes with any necessary escaping applied. The reason for bundling this up with the other methods in this interface is that we basically always need to make use of this when creating new command objects.
	Quote(str string) string
}

// poor man's version of explicitly saying that struct X implements interface Y
var _ ICmdObjBuilder = &CmdObjBuilder{}

type CmdObjBuilder struct {
	runner    ICmdObjRunner
	logCmdObj func(ICmdObj)
	// TODO: see if you can just remove this entirely and use secureexec.Command,
	// now that we're mocking out the runner itself.
	command  func(string, ...string) *exec.Cmd
	platform *Platform
}

func (self *CmdObjBuilder) New(cmdStr string) ICmdObj {
	args := str.ToArgv(cmdStr)
	cmd := self.command(args[0], args[1:]...)
	cmd.Env = os.Environ()

	return &CmdObj{
		cmdStr:     cmdStr,
		cmd:        cmd,
		runner:     self.runner,
		logCommand: self.logCmdObj,
	}
}

func (self *CmdObjBuilder) NewFromArgs(args []string) ICmdObj {
	cmd := self.command(args[0], args[1:]...)
	cmd.Env = os.Environ()

	return &CmdObj{
		cmdStr:     strings.Join(args, " "),
		cmd:        cmd,
		runner:     self.runner,
		logCommand: self.logCmdObj,
	}
}

func (self *CmdObjBuilder) NewShell(commandStr string) ICmdObj {
	return self.NewFromArgs([]string{self.platform.Shell, self.platform.ShellArg, commandStr})
}

func (self *CmdObjBuilder) CloneWithNewRunner(decorate func(ICmdObjRunner) ICmdObjRunner) *CmdObjBuilder {
	decoratedRunner := decorate(self.runner)

	return &CmdObjBuilder{
		runner:    decoratedRunner,
		logCmdObj: self.logCmdObj,
		command:   self.command,
		platform:  self.platform,
	}
}