package main

import (
	"fmt"
	"os"

	tea "github.com/charmbracelet/bubbletea"
)

const (
	BrowserSessions int = iota // Enumerating the sections
	Commands
)

type sessionOrCommand struct {
	displayString string
	commandString string
}

type Choices [][]sessionOrCommand

type model struct {
	activeSection int
	cursor        []int
	choices       Choices
	selected      []map[int]struct{}
}

func getBrowserSessions() []sessionOrCommand {
	// Placeholder
	return []sessionOrCommand{{
		displayString: "primary",
		commandString: "",
	}, {
		displayString: "breakfast",
		commandString: "",
	}}
}

func initialModel() model {
	return model{
		activeSection: BrowserSessions,
		// Need syntax of two-dimensional slices
		choices: Choices{
			getBrowserSessions(),
			[]sessionOrCommand{{
				displayString: "neomutt",
				commandString: "neomutt",
			}, {
				displayString: "bottom",
				commandString: "btm --group --battery --color gruvbox-light",
			}},
		},
		// An array maps which indicates which choices are selected. We're
		// using the map like a mathematical set. The keys refer to the
		// indexes of the `choices` slice, above.
		selected: make([]map[int]struct{}, 32, 32),
	}
}

func (m model) Init() tea.Cmd {
	return nil
}

func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.KeyMsg:
		switch msg.String() {
		case "ctrl+c", "q":
			return m, tea.Quit
		case "up", "k":
			if m.cursor[m.activeSection] > 0 {
				m.cursor[m.activeSection]--
			}
		case "down", "j":
			if m.cursor[m.activeSection] < len(m.browserSessions)+len(m.commands)-1 {
				m.cursor[m.activeSection]++
			}
		case "enter", " ":
			// TODO: Let's have two separate cursors, and have tab move the active
			// set from brower sessions to terminals.
			if m.cursor[m.activeSection] < len(m.browserSessions)-1 {
				_, ok := m.selected[m.cursor]
				if ok {
					delete(m.selected, m.cursor)
				} else {
					m.selected[m.cursor] = struct{}{}
				}
			} else {
				_, ok := m.selected[m.cursor]
				if ok {
					delete(m.selected, m.cursor)
				} else {
					m.selected[m.cursor] = struct{}{}
				}
			}
		}
	}

	return m, nil
}

func (m model) View() string {
	s := "What should we buy at the market?\n\n"

	for i, choice := range m.choices {
		cursor := " "
		if m.cursor == i {
			cursor = ">"
		}

		checked := " "
		if _, ok := m.selected[i]; ok {
			checked = "x"
		}

		s += fmt.Sprintf("%s [%s] %s\n", cursor, checked, choice)
	}

	s += "\nPress q to quit.\n"

	return s
}

func main() {
	p := tea.NewProgram(initialModel())
	if err := p.Start(); err != nil {
		fmt.Printf("Alas, there's been an error: %v", err)
		os.Exit(1)
	}
}