package main

import (
	"flag"
	"fmt"
	"os"
	"path/filepath"
	"strings"

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

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 = 2

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 // fuzzy search interface
	datasheets     []string        // all datasheets under cwd
	dataSheetsView []string        // filtered view on all datasheets
}

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

	var ds []string
	// TODO(d1): handle error in interface?
	_ = filepath.Walk(".", func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}

		name := info.Name()
		if strings.HasSuffix(name, "pdf") {
			ds = append(ds, name)
		}

		return nil
	})

	return model{
		filterInput:    input,
		datasheets:     ds,
		dataSheetsView: ds,
	}
}

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 matched []string

		search := m.filterInput.Value()
		if len(search) >= minCharsUntilFilter {
			matches := fuzzy.Find(search, m.datasheets)
			for _, match := range matches {
				matched = append(matched, match.Str)
			}

			if len(matches) > 0 {
				m.dataSheetsView = matched
			} else {
				m.dataSheetsView = m.datasheets
			}
		} else {
			m.dataSheetsView = m.datasheets
		}

	}

	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.dataSheetsView, "\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)
	}
}