package stages

import (
	"fmt"
	"net/http"
	"strings"

	"gitea.konchin.com/ytshih/inp2025/models"
	"github.com/charmbracelet/bubbles/textinput"
	tea "github.com/charmbracelet/bubbletea"
)

type landingOperationType int

const (
	landingOperationChoose landingOperationType = iota
	landingOperationLoginCred
	landingOperationRegistCred
)

type focusTargetType int

const (
	focusTargetUsername focusTargetType = iota
	focusTargetPassword
)

type LandingModel struct {
	*BaseModel
	op landingOperationType

	focus    focusTargetType
	username textinput.Model
	password textinput.Model

	info string
	err  error
}

func NewLandingModel(base *BaseModel) *LandingModel {
	username := textinput.New()
	username.Placeholder = "Username"
	username.CharLimit = 32
	username.Width = 32
	username.Blur()

	password := textinput.New()
	password.Placeholder = "Password"
	password.CharLimit = 32
	password.Width = 32
	password.Blur()
	password.EchoMode = textinput.EchoPassword
	password.EchoCharacter = '•'

	return &LandingModel{
		BaseModel: base,
		op:        landingOperationChoose,

		username: username,
		password: password,
	}
}

func (m *LandingModel) reset() {
	m.op = landingOperationChoose
	m.username.Blur()
	m.username.Reset()
	m.password.Blur()
	m.password.Reset()
}

type postLoginMsg struct{}

func (m *LandingModel) postLogin() tea.Cmd {
	return func() tea.Msg {
		resp, err := m.BaseModel.client.R().
			SetBasicAuth(m.username.Value(), m.password.Value()).
			Post("/auth/login")
		if err == nil {
			switch resp.StatusCode() {
			case http.StatusOK:
				m.BaseModel.client.SetBasicAuth(
					m.username.Value(), m.password.Value())
				m.info = "login success.\n"
				m.err = nil
			case http.StatusUnauthorized:
				m.err = fmt.Errorf("user not exist or password incorrect, %s",
					string(resp.Body()))
			default:
				m.err = fmt.Errorf("unknown server error, %s",
					string(resp.Body()))
			}
		} else {
			m.err = fmt.Errorf("failed to post login, %w", err)
		}
		return postLoginMsg{}
	}
}

type postRegisterMsg struct{}

func (m *LandingModel) postRegister() tea.Cmd {
	return func() tea.Msg {
		resp, err := m.BaseModel.client.R().
			SetBody(models.User{
				Username: m.username.Value(),
				Password: m.password.Value(),
			}).
			Post("/auth/register")
		if err == nil {
			switch resp.StatusCode() {
			case http.StatusOK:
				m.info = "register success.\n"
				m.err = nil
			case http.StatusBadRequest:
				m.err = fmt.Errorf("username already exist, %s",
					string(resp.Body()))
			default:
				m.err = fmt.Errorf("unknown server error, %s",
					string(resp.Body()))
			}
		} else {
			m.err = fmt.Errorf("failed to post register, %s",
				string(resp.Body()))
		}
		return postRegisterMsg{}
	}
}

func (m *LandingModel) Init() tea.Cmd {
	return tea.ClearScreen
}

func (m *LandingModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	var cmds []tea.Cmd

	switch msg := msg.(type) {
	case tea.KeyMsg:
		switch msg.String() {
		case "ctrl+c":
			return m, tea.Quit
		case "L", "l":
			if m.op == landingOperationChoose {
				m.op = landingOperationLoginCred
				m.focus = focusTargetUsername
				cmds = append(cmds, m.username.Focus())
				return m, tea.Batch(cmds...)
			}
		case "R", "r":
			if m.op == landingOperationChoose {
				m.op = landingOperationRegistCred
				m.focus = focusTargetUsername
				cmds = append(cmds, m.username.Focus())
				return m, tea.Batch(cmds...)
			}
		case "shift+tab", "up":
			if m.op == landingOperationLoginCred ||
				m.op == landingOperationRegistCred {
				switch m.focus {
				case focusTargetUsername:
					m.username.Blur()
					m.focus = focusTargetPassword
					cmds = append(cmds, m.password.Focus())
				case focusTargetPassword:
					m.password.Blur()
					m.focus = focusTargetUsername
					cmds = append(cmds, m.username.Focus())
				}
			}
		case "tab", "down", "enter":
			if m.op == landingOperationLoginCred ||
				m.op == landingOperationRegistCred {
				switch m.focus {
				case focusTargetUsername:
					m.username.Blur()
					m.focus = focusTargetPassword
					cmds = append(cmds, m.password.Focus())
				case focusTargetPassword:
					if msg.String() == "enter" {
						switch m.op {
						case landingOperationLoginCred:
							cmds = append(cmds, m.postLogin())
						case landingOperationRegistCred:
							cmds = append(cmds, m.postRegister())
						}
					} else {
						m.password.Blur()
						m.focus = focusTargetUsername
						cmds = append(cmds, m.username.Focus())
					}
				}
			}
		}
	case postLoginMsg:
		if m.err == nil {
			*m.queue = append(*m.queue,
				tea.NewProgram(NewLobbyModel(m.BaseModel)))
			return m, tea.Quit
		} else {
			m.reset()
		}
	case postRegisterMsg:
		m.reset()
	}

	var cmd tea.Cmd
	m.username, cmd = m.username.Update(msg)
	cmds = append(cmds, cmd)
	m.password, cmd = m.password.Update(msg)
	cmds = append(cmds, cmd)

	return m, tea.Batch(cmds...)
}

func (m *LandingModel) View() string {
	var b strings.Builder

	switch m.op {
	case landingOperationChoose:
		fmt.Fprintf(&b, "Choose Operation\n(L)ogin / (R)egister\n")
	case landingOperationLoginCred:
		fmt.Fprintf(&b, "Login: \n")
		b.WriteString(m.username.View() + "\n")
		b.WriteString(m.password.View() + "\n")
	case landingOperationRegistCred:
		fmt.Fprintf(&b, "Register: \n")
		b.WriteString(m.username.View() + "\n")
		b.WriteString(m.password.View() + "\n")
	}

	if m.info != "" {
		b.WriteString(m.info + "\n")
	}

	if m.err != nil {
		b.WriteString("----------\n")
		b.WriteString(m.err.Error() + "\n")
	}

	return b.String()
}