package ui

import (
	"fmt"
	"strings"

	"github.com/charmbracelet/bubbles/viewport"
	tea "github.com/charmbracelet/bubbletea"
)

const (
	// Status is the status buffer.
	Status = iota
	// Profile is the profile buffer.
	Profile
)

// BufferHandler is the concrete functionality of a Buffer.
type BufferHandler interface {
	validateInput(m model, input string) error     // validate incoming input
	handleInput(input, hiddenInput string) tea.Msg // handle and dispatch messages from input
	logToFile(m model, input string)               // log input to file if persistence is enabled
}

// Buffer is a user-facing interactive buffer in the TUI.
type Buffer struct {
	menuBarName          string         // user-friendly buffer name for the menu
	inputChannel         chan string    // channel for passing input to handlers
	viewport             viewport.Model // viewport for rendering lines
	viewportLines        []string       // lines for viewport renderer
	viewportIsReady      bool           // whether or not the viewport is ready to render
	persistenceIsEnabled bool           // whether or not to persist buffer input to file

	BufferHandler
}

// StatusBuffer is the privileged status buffer where e.g. you input
// program-wide commands. It can also report general status information, e.g.
// the status of ACN connectivity.
type StatusBufferHandler Buffer

func (s StatusBufferHandler) validateInput(m model, input string) error {
	if string(input[0]) != "/" {
		return fmt.Errorf("Woops, this is not a chat buffer. Only commands are allowed")
	}
	return nil
}

func (s StatusBufferHandler) handleInput(input, hiddenInput string) tea.Msg {
	cmds := strings.Split(input, " ")

	switch {
	case cmds[0] == "help":
		return cmdMsg{output: strings.Split(cmdHelp, "\n")}

	case cmds[0] == "quit":
		return turnAcnOffMsg{quitProgram: true}

	case cmds[0] == "start":
		return showGettingStartedGuideMsg{}

	case cmds[0] == "profile":
		if cmds[1] != "unlock" && cmds[1] != "info" && cmds[1] != "create" {
			profileHelp := `Unknown "profile" command?
/profile create <name> <password> <password> | Create a new profile
/profile info                                | Show profile information
/profile unlock <password>                   | Unlock profile(s)`
			return cmdMsg{output: strings.Split(profileHelp, "\n")}
		}

		switch {
		case cmds[1] == "unlock":
			if len(cmds) != 3 {
				return cmdMsg{output: strings.Split(cmdHelp, "\n")}
			}

			return profileUnlockMsg{
				password: strings.TrimSpace(hiddenInput),
			}

		case cmds[1] == "info":
			return profileInfoMsg{}

		case cmds[1] == "create":
			if len(cmds) != 5 {
				return cmdMsg{output: strings.Split(cmdHelp, "\n")}
			}

			passwords := strings.Split(strings.TrimSpace(hiddenInput), " ")
			if len(passwords) != 2 {
				return cmdMsg{output: []string{"Profile create: unable to parse hidden input"}}
			}

			if passwords[0] != passwords[1] {
				return cmdMsg{output: []string{"Profile create: passwords do not match?"}}
			}

			return profileCreateMsg{
				name:     cmds[2],
				password: passwords[1],
			}
		}

	case cmds[0] == "acn":
		if cmds[1] != "on" && cmds[1] != "off" {
			acnHelp := `Unknown "acn" command?
/acn on  | Turn on the Tor ACN
/acn off | Turn off the Tor ACN`
			return cmdMsg{output: strings.Split(acnHelp, "\n")}
		}

		switch {
		case cmds[1] == "on":
			return turnAcnOnMsg{}
		case cmds[1] == "off":
			return turnAcnOffMsg{}
		}

	case cmds[0] == "clear":
		return clearScreenMsg{}
	}

	return cmdMsg{output: []string{unknownCmdHelp}}
}

func (s StatusBufferHandler) logToFile(m model, input string) {
	if !s.persistenceIsEnabled {
		return
	}
	// TODO: implement saving to file under ~/.cairde
}

// ProfileBuffer is the profile buffer. There can be several profile buffers
// which correspond to several profiles. Profile buffers take input and report
// output for profile-specific information, e.g. invites from a new contact.
type ProfileBuffer Buffer