package tui

import (
	"fmt"
	"strings"

	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"
	"github.com/charmbracelet/soft-serve/internal/config"
	"github.com/charmbracelet/soft-serve/internal/tui/bubbles/repo"
	"github.com/charmbracelet/soft-serve/internal/tui/bubbles/selection"
	"github.com/charmbracelet/soft-serve/internal/tui/style"
	"github.com/charmbracelet/soft-serve/tui/common"
	"github.com/gliderlabs/ssh"
)

const (
	repoNameMaxWidth = 32
)

type sessionState int

const (
	startState sessionState = iota
	errorState
	loadedState
	quittingState
	quitState
)

type SessionConfig struct {
	Width       int
	Height      int
	InitialRepo string
	Session     ssh.Session
}

type MenuEntry struct {
	Name   string `json:"name"`
	Note   string `json:"note"`
	Repo   string `json:"repo"`
	bubble *repo.Bubble
}

type Bubble struct {
	config      *config.Config
	styles      *style.Styles
	state       sessionState
	error       string
	width       int
	height      int
	initialRepo string
	repoMenu    []MenuEntry
	boxes       []tea.Model
	activeBox   int
	repoSelect  *selection.Bubble
	session     ssh.Session

	// remember the last resize so we can re-send it when selecting a different repo.
	lastResize tea.WindowSizeMsg
}

func NewBubble(cfg *config.Config, sCfg *SessionConfig) *Bubble {
	b := &Bubble{
		config:      cfg,
		styles:      style.DefaultStyles(),
		width:       sCfg.Width,
		height:      sCfg.Height,
		repoMenu:    make([]MenuEntry, 0),
		boxes:       make([]tea.Model, 2),
		initialRepo: sCfg.InitialRepo,
		session:     sCfg.Session,
	}
	b.state = startState
	return b
}

func (b *Bubble) Init() tea.Cmd {
	return b.setupCmd
}

func (b *Bubble) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	cmds := make([]tea.Cmd, 0)
	switch msg := msg.(type) {
	case tea.KeyMsg:
		switch msg.String() {
		case "q", "ctrl+c":
			return b, tea.Quit
		case "tab", "shift+tab":
			b.activeBox = (b.activeBox + 1) % 2
		}
	case errMsg:
		b.error = msg.Error()
		b.state = errorState
		return b, nil
	case tea.WindowSizeMsg:
		b.lastResize = msg
		b.width = msg.Width
		b.height = msg.Height
		if b.state == loadedState {
			for i, bx := range b.boxes {
				m, cmd := bx.Update(msg)
				b.boxes[i] = m
				if cmd != nil {
					cmds = append(cmds, cmd)
				}
			}
		}
	case selection.SelectedMsg:
		b.activeBox = 1
		rb := b.repoMenu[msg.Index].bubble
		b.boxes[1] = rb
	case selection.ActiveMsg:
		b.boxes[1] = b.repoMenu[msg.Index].bubble
		cmds = append(cmds, func() tea.Msg {
			return b.lastResize
		})
	}
	if b.state == loadedState {
		ab, cmd := b.boxes[b.activeBox].Update(msg)
		b.boxes[b.activeBox] = ab
		if cmd != nil {
			cmds = append(cmds, cmd)
		}
	}
	return b, tea.Batch(cmds...)
}

func (b *Bubble) viewForBox(i int) string {
	isActive := i == b.activeBox
	switch box := b.boxes[i].(type) {
	case *selection.Bubble:
		// Menu
		var s lipgloss.Style
		s = b.styles.Menu
		if isActive {
			s = s.Copy().BorderForeground(b.styles.ActiveBorderColor)
		}
		return s.Render(box.View())
	case *repo.Bubble:
		// Repo details
		box.Active = isActive
		return box.View()
	default:
		panic(fmt.Sprintf("unknown box type %T", box))
	}
}

func (b Bubble) headerView() string {
	w := b.width - b.styles.App.GetHorizontalFrameSize()
	name := ""
	if b.config != nil {
		name = b.config.Name
	}
	return b.styles.Header.Copy().Width(w).Render(name)
}

func (b Bubble) footerView() string {
	w := &strings.Builder{}
	var h []common.HelpEntry
	if b.state != errorState {
		h = []common.HelpEntry{
			{Key: "tab", Value: "section"},
		}
		if box, ok := b.boxes[b.activeBox].(common.BubbleHelper); ok {
			help := box.Help()
			for _, he := range help {
				h = append(h, he)
			}
		}
	}
	h = append(h, common.HelpEntry{Key: "q", Value: "quit"})
	for i, v := range h {
		fmt.Fprint(w, helpEntryRender(v, b.styles))
		if i != len(h)-1 {
			fmt.Fprint(w, b.styles.HelpDivider)
		}
	}
	branch := ""
	if b.state == loadedState {
		ref := b.boxes[1].(*repo.Bubble).Reference()
		branch = ref.Name().Short()
	}
	help := w.String()
	branchMaxWidth := b.width - // bubble width
		lipgloss.Width(help) - // help width
		b.styles.App.GetHorizontalFrameSize() // App paddings
	branch = b.styles.Branch.Render(common.TruncateString(branch, branchMaxWidth-1, "…"))
	gap := lipgloss.NewStyle().
		Width(b.width -
			lipgloss.Width(help) -
			lipgloss.Width(branch) -
			b.styles.App.GetHorizontalFrameSize()).
		Render("")
	footer := lipgloss.JoinHorizontal(lipgloss.Top, help, gap, branch)
	return b.styles.Footer.Render(footer)
}

func (b Bubble) errorView() string {
	s := b.styles
	str := lipgloss.JoinHorizontal(
		lipgloss.Top,
		s.ErrorTitle.Render("Bummer"),
		s.ErrorBody.Render(b.error),
	)
	h := b.height -
		s.App.GetVerticalFrameSize() -
		lipgloss.Height(b.headerView()) -
		lipgloss.Height(b.footerView()) -
		s.RepoBody.GetVerticalFrameSize() +
		3 // TODO: this is repo header height -- get it dynamically
	return s.Error.Copy().Height(h).Render(str)
}

func (b Bubble) View() string {
	s := strings.Builder{}
	s.WriteString(b.headerView())
	s.WriteRune('\n')
	switch b.state {
	case loadedState:
		lb := b.viewForBox(0)
		rb := b.viewForBox(1)
		s.WriteString(lipgloss.JoinHorizontal(lipgloss.Top, lb, rb))
	case errorState:
		s.WriteString(b.errorView())
	}
	s.WriteRune('\n')
	s.WriteString(b.footerView())
	return b.styles.App.Render(s.String())
}

func helpEntryRender(h common.HelpEntry, s *style.Styles) string {
	return fmt.Sprintf("%s %s", s.HelpKey.Render(h.Key), s.HelpValue.Render(h.Value))
}