package main

import (
	"fmt"
	"io"
	"os"
	"strings"
	"sync"
)

var (
	executeMu     sync.Mutex
	commandStdout io.Writer = os.Stdout
	commandStderr io.Writer = os.Stderr
)

func Execute(args []string, stdout, stderr io.Writer) int {
	executeMu.Lock()
	defer executeMu.Unlock()

	prevStdout := commandStdout
	prevStderr := commandStderr
	commandStdout = stdout
	commandStderr = stderr
	defer func() {
		commandStdout = prevStdout
		commandStderr = prevStderr
	}()

	if len(args) < 1 {
		usage()
		return 2
	}
	if args[0] == "help" {
		if len(args) == 1 {
			usage()
			return 0
		}
		if err := runCommand([]string{args[1], "--help"}); err != nil {
			_, _ = fmt.Fprintln(commandStderr, err)
			return 1
		}
		return 0
	}
	if isHelpToken(args[0]) {
		usage()
		return 0
	}

	if err := runCommand(args); err != nil {
		_, _ = fmt.Fprintln(commandStderr, err)
		return 1
	}

	return 0
}

func isHelpToken(value string) bool {
	switch strings.TrimSpace(value) {
	case "-h", "--help":
		return true
	default:
		return false
	}
}

func runCommand(args []string) error {
	switch args[0] {
	case "init":
		return runInit(args[1:])
	case "add":
		return runAdd(args[1:])
	case "ingest":
		return runIngest(args[1:])
	case "search":
		return runSearch(args[1:])
	case "list":
		return runList(args[1:])
	case "events":
		return runEvents(args[1:])
	case "link":
		return runLink(args[1:])
	case "verify":
		return runVerify(args[1:])
	case "repos":
		return runRepos(args[1:])
	default:
		usage()
		return fmt.Errorf("unknown command %s", args[0])
	}
}