package main

import (
	"flag"
	"fmt"
	"os"
	"strings"

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

const help = `go-sh-manymanuals: TODO

TODO

Options:
	-h    output help
`

// minCharsUntilFilter is the minimum amount of characters that are
// required before the filtering logic commences actually filtering.
const minCharsUntilFilter = 3

var helpFlag bool

type Configuration struct {
	ManualDir string
}

func handleCliFlags() {
	flag.BoolVar(&helpFlag, "h", false, "output help")
	flag.Parse()
}

type model struct {
	filterInput textinput.Model
	datasheets  []string
}

func initialModel() model {
	input := textinput.New()
	input.Focus()

	return model{
		filterInput: input,
		datasheets:  []string{},
	}
}

func (m model) Init() tea.Cmd {
	// TODO(d1): implement reading all PDFs in cwd
	// https://stackoverflow.com/a/67214584
	// requires error reporting also
	return textinput.Blink
}

func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	var cmd tea.Cmd

	if m.filterInput.Focused() {
		var filtered []string

		search := m.filterInput.Value()
		if len(search) >= minCharsUntilFilter {
			// NOTE(d1): naive prototype implementation
			for _, ds := range m.datasheets {
				if strings.HasPrefix(ds, search) {
					filtered = append(filtered, ds)
				}
			}
			m.datasheets = filtered
		}
	}

	switch msg := msg.(type) {
	case tea.KeyMsg:
		switch msg.String() {
		case "ctrl+c", "q":
			return m, tea.Quit
		}
	}

	m.filterInput, cmd = m.filterInput.Update(msg)

	return m, cmd
}

func (m model) View() string {
	body := strings.Builder{}

	body.WriteString(strings.Join(m.datasheets, "\n") + "\n")

	body.WriteString(m.filterInput.View() + "\n")

	return body.String()
}

func main() {
	handleCliFlags()

	if helpFlag {
		fmt.Printf(help)
		os.Exit(0)
	}

	p := tea.NewProgram(initialModel(), tea.WithAltScreen())
	if err := p.Start(); err != nil {
		fmt.Printf("oops, something went wrong: %v", err)
		os.Exit(1)
	}
}