package parser

import (
	"fmt"

	"github.com/deis/deis/client-go/cmd"
	docopt "github.com/docopt/docopt-go"
)

// Ps routes ps commands to their specific function.
func Ps(argv []string) error {
	usage := `
Valid commands for processes:

ps:list        list application processes
ps:restart     restart an application or its process types
ps:scale       scale processes (e.g. web=4 worker=2)

Use 'deis help [command]' to learn more.
`
	if len(argv) < 2 {
		return psList([]string{"ps:list"})
	}

	switch argv[1] {
	case "list":
		return psList(combineCommand(argv))
	case "restart":
		return psRestart(combineCommand(argv))
	case "scale":
		return psScale(combineCommand(argv))
	case "--help":
		fmt.Print(usage)
		return nil
	default:
		PrintUsage()
		return nil
	}
}

func psList(argv []string) error {
	usage := `
Lists processes servicing an application.

Usage: deis ps:list [options]

Options:
  -a --app=<app>
    the uniquely identifiable name for the application.
`

	args, err := docopt.Parse(usage, argv, true, "", false, true)

	if err != nil {
		return err
	}

	return cmd.PsList(safeGetValue(args, "--app"))
}

func psRestart(argv []string) error {
	usage := `
Restart an application, a process type or a specific process.

Usage: deis ps:restart [<type>] [options]

Arguments:
  <type>
    the process name as defined in your Procfile, such as 'web' or 'worker'.
    To restart a particular process, use 'web.1'.

Options:
  -a --app=<app>
    the uniquely identifiable name for the application.
`

	args, err := docopt.Parse(usage, argv, true, "", false, true)

	if err != nil {
		return err
	}

	return cmd.PsRestart(safeGetValue(args, "--app"), safeGetValue(args, "<type>"))
}

func psScale(argv []string) error {
	usage := `
Scales an application's processes by type.

Usage: deis ps:scale <type>=<num>... [options]

Arguments:
  <type>
    the process name as defined in your Procfile, such as 'web' or 'worker'.
    Note that Dockerfile apps have a default 'cmd' process type.
  <num>
    the number of processes.

Options:
  -a --app=<app>
    the uniquely identifiable name for the application.
`

	args, err := docopt.Parse(usage, argv, true, "", false, true)

	if err != nil {
		return err
	}

	return cmd.PsScale(safeGetValue(args, "--app"), args["<type>=<num>"].([]string))
}