package commands

import (
	"fmt"
	"log"
	"strings"

	"git.snorba.art/hugo/nssh/storage"
)

type CommandHandler struct {
	shell     *Shell
	filestore storage.Filestore
}

func NewCommandHandler(shell *Shell, filestore storage.Filestore) *CommandHandler {
	return &CommandHandler{
		shell:     shell,
		filestore: filestore,
	}
}

func (h *CommandHandler) Handle(comm *Command) error {
	if strings.Contains(comm.Name, "=") {
		ApplyEnvIfPresent(h.shell, comm)
		return nil
	}

	switch comm.Name {
	case "exec":
		ApplyEnvIfPresent(h.shell, comm)
	case "(cd":
		h.shell.WriteOutput([]byte("tramp_exit_status 0\n"))
	case "echo":
		(&EchoCommand{}).Execute(h.shell, comm.Arguments)
	case "(echo":
		if strings.Join(comm.Arguments, " ") == "foo ; echo bar)" {
			log.Println("Handling tramp's foobar test")
			h.shell.WriteOutputString("foo\nbar\n")
		}
	case "stty":
		return (&SttyCommand{}).Execute(h.shell, comm.Arguments)
	case "set":
		log.Println("Ignoring \"set\" command")
	case "locale":
		if len(comm.Arguments) > 0 {
			if comm.Arguments[0] == "-a" {
				locales := []string{"C", "C.UTF-8", "POSIX", "en_US.utf8"}
				log.Println("Tramp requested locale, returning fake values: ", locales)
				h.shell.WriteOutputString(
					strings.Join(locales, "\n") + "\n",
				)
				return nil
			}
		}

		log.Println("Ignoring \"locale\" command with unsupported parameters: ", comm.Arguments)
	case "getconf":
		return (&GetConfCommand{}).Execute(h.shell, comm.Arguments)
	case "test", "/bin/test":
		return (&TestCommand{filestore: h.filestore}).Execute(h.shell, comm.Arguments)
	case "while":
		if len(comm.Arguments) > 6 {
			var err error

			log.Printf("Pointing tramp to executable for \"%s\"", comm.Arguments[6])

			switch comm.Arguments[6] {
			case "$d/ls":
				_, err = h.shell.WriteOutputString("tramp_executable " + lsExecutable)
			case "$d/test":
				_, err = h.shell.WriteOutputString("tramp_executable " + testExecutable)
			case "$d/stat":
				_, err = h.shell.WriteOutputString("tramp_executable " + statExecutable)
			}
			return err
		}
	case "ls", "/bin/ls":
		if len(comm.Arguments) > 2 &&
			comm.Arguments[1] == "-al" &&
			comm.Arguments[2] == "/dev/null" {
			_, err := h.shell.WriteOutputString(
				fmt.Sprintf(
					"crw-rw-rw- 1 root root 1, 3 May  5 00:05 /dev/null\n%s",
					trampSuccess,
				),
			)

			return err
		}

		if len(comm.Arguments) > 1 && comm.Arguments[0] == "-lnd" {
			_, err := h.shell.WriteOutputString(
				fmt.Sprintf(
					"drwxrwxr-x 3 1000 1000 28 Apr 28 14:04 %s\n%s",
					comm.Arguments[1],
					trampSuccess,
				),
			)

			return err
		}

		// should handle "--color=never --help 2>&1 | grep -iq busybox" so that we
		// can pretend to have busybox ls. The assumption is that this is easier
		// to emulate than the --dired flag of ls
		if len(comm.Arguments) > 7 &&
			comm.Arguments[4] == "grep" &&
			comm.Arguments[6] == "busybox" {
			_, err := h.shell.WriteOutputString(trampSuccess)
			return err
		}

		_, err := h.shell.WriteOutputString(trampFailure)
		return err
	case "mkdir":
		return (&MkdirCommand{filestore: h.filestore}).Execute(comm.Arguments)
	default:
		log.Printf("Error: Received unexpected command %s", comm.Name)
	}

	return nil
}