package tui

import (
	tea "github.com/charmbracelet/bubbletea"

	"github.com/lerko/nib/internal/db"
)

type viewState int

const (
	stateList viewState = iota
	stateDetail
	stateInput
)

type model struct {
	store  *db.Store
	state  viewState
	width  int
	height int

	list   listModel
	detail detailModel
	input  inputModel

	status string
	err    error
}

func newModel(store *db.Store) model {
	return model{
		store:  store,
		state:  stateList,
		list:   newListModel(),
		detail: newDetailModel(),
		input:  newInputModel(),
	}
}

func (m model) Init() tea.Cmd {
	return loadEntities(m.store, db.DefaultListParams())
}

func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.WindowSizeMsg:
		m.width = msg.Width
		m.height = msg.Height
		m.list.setSize(m.width, m.contentHeight())
		m.detail.setSize(m.width, m.contentHeight())
		return m, nil

	case entitiesLoadedMsg:
		m.list.setEntities(msg.entities)
		m.status = ""
		m.err = nil
		return m, nil

	case entityCreatedMsg:
		m.state = stateList
		m.input.reset()
		m.status = "created"
		return m, loadEntities(m.store, db.DefaultListParams())

	case entityDeletedMsg:
		m.status = "deleted"
		return m, loadEntities(m.store, db.DefaultListParams())

	case errMsg:
		m.err = msg.err
		return m, nil

	case tea.KeyMsg:
		if m.state == stateInput {
			return m.updateInput(msg)
		}
		return m.updateKeys(msg)
	}

	return m, nil
}

func (m model) updateKeys(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
	switch {
	case msg.String() == "q" || msg.String() == "ctrl+c":
		return m, tea.Quit

	case msg.String() == "a" && m.state == stateList:
		m.state = stateInput
		m.input.focus()
		return m, m.input.ti.Focus()

	case msg.String() == "esc":
		if m.state == stateDetail {
			m.state = stateList
		}
		return m, nil

	case msg.String() == "enter" && m.state == stateList:
		if e := m.list.selected(); e != nil {
			m.detail.setEntity(e)
			m.state = stateDetail
		}
		return m, nil

	case msg.String() == "d" && m.state == stateList:
		if e := m.list.selected(); e != nil {
			return m, deleteEntity(m.store, e.ID)
		}
		return m, nil
	}

	switch m.state {
	case stateList:
		m.list = m.list.update(msg)
	case stateDetail:
		m.detail = m.detail.update(msg)
	}
	return m, nil
}

func (m model) updateInput(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
	switch msg.String() {
	case "esc":
		m.state = stateList
		m.input.reset()
		return m, nil
	case "enter":
		if e := m.input.submit(); e != nil {
			return m, createEntity(m.store, e)
		}
		return m, nil
	}

	m.input = m.input.updateKey(msg)
	return m, nil
}

func (m model) View() string {
	var content string

	switch m.state {
	case stateList:
		content = m.list.view(m.width)
	case stateDetail:
		content = m.detail.view(m.width)
	case stateInput:
		content = m.list.view(m.width)
	}

	header := titleStyle.Render("nib")
	footer := m.footerView()

	return header + "\n" + content + "\n" + footer
}

func (m model) footerView() string {
	if m.state == stateInput {
		return m.input.view(m.width)
	}

	if m.err != nil {
		return errorStyle.Render("error: " + m.err.Error())
	}

	if m.status != "" {
		return statusStyle.Render(m.status)
	}

	return helpStyle.Render("a:add  enter:view  d:delete  q:quit  ?:help")
}

func (m model) contentHeight() int {
	return m.height - 3
}