package main

// A simple program demonstrating the textarea component from the Bubbles
// component library.

import (
	"fmt"
	"io"
	"log"
	"os"
	"path/filepath"
	"strings"
	"time"

	"charm.land/bubbles/v2/textarea"
	tea "charm.land/bubbletea/v2"
	"charm.land/lipgloss/v2"
	"code.ppl.town/justin/journal/config"
)

func main() {

	cfg, created, err := config.LoadOrCreate()
	if err != nil {
		fmt.Printf("could not get config: %s", err.Error())
		os.Exit(1)
	}
	if created {
		cp, _ := config.Path()
		fmt.Printf("configuration created at '%s' - please check and re-run\n", cp)
		os.Exit(0)
	}

	p := tea.NewProgram(initialModel(cfg))

	if _, err := p.Run(); err != nil {
		log.Fatal(err)
	}
}

type transientMsg struct {
	msg   string
	until time.Time
}

type WriteSeekCloser interface {
	io.WriteSeeker
	io.Closer
	Sync() error
}

type model struct {
	textarea      textarea.Model
	fh            WriteSeekCloser
	title         string
	transientMsgs []transientMsg
}

func getWriter(cfg config.Config) (WriteSeekCloser, error) {
	fp := cfg.JournalDir
	fpS, err := os.Stat(fp)
	if err != nil {
		return nil, err
	}
	if !fpS.IsDir() {
		return nil, fmt.Errorf("fp: %s is not a dir", fp)
	}

	fn := fmt.Sprintf("journal-%s", time.Now().Format("2006-01-02_150405.md"))

	file, err := os.Create(filepath.Join(fp, fn))
	if err != nil {
		return nil, err
	}
	return file, nil
}

func initialModel(cfg config.Config) model {
	ti := textarea.New()
	ti.Placeholder = "What's happening Peter ..."
	ti.SetVirtualCursor(false)
	ti.SetStyles(textarea.DefaultStyles(true)) // default to dark styles.
	ti.Focus()

	ti.SetHeight(20)
	ti.SetWidth(80)

	fh, err := getWriter(cfg)
	if err != nil {
		panic(err)
	}
	return model{
		title:    time.Now().Format("2006-01-02 15:04"),
		textarea: ti,
		fh:       fh,
	}
}

func (m model) Init() tea.Cmd {
	return tea.Batch(textarea.Blink, tea.RequestBackgroundColor)
}

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

	// clean out transient msgs
	newMsgs := []transientMsg{}
	for _, message := range m.transientMsgs {
		if message.until.After(time.Now()) {
			newMsgs = append(newMsgs, message)
		}
	}

	m.transientMsgs = newMsgs

	switch msg := msg.(type) {
	case tea.WindowSizeMsg:
		m.textarea.SetHeight(msg.Height - 5)
		m.textarea.SetWidth(msg.Width - 6)
	case tea.BackgroundColorMsg:
		// Update styling now that we know the background color.
		m.textarea.SetStyles(textarea.DefaultStyles(msg.IsDark()))
	case tea.KeyPressMsg:
		switch msg.String() {
		case "super+s", "ctrl+s":
			var err error
			err = m.writeFile()
			m.transientMsgs = append(m.transientMsgs, transientMsg{
				msg:   "saved",
				until: time.Now().Add(time.Second * 2),
			})
			if err != nil {
				m.transientMsgs = append(m.transientMsgs, transientMsg{
					msg:   "saved",
					until: time.Now().Add(time.Second * 2),
				})
				panic(err)
			}
		case "esc":
			if m.textarea.Focused() {
				m.textarea.Blur()
			}
		case "ctrl+c":
			var err error
			err = m.writeFile()
			if err == nil {
				err = m.fh.Close()
			}
			if err == nil {
				return m, tea.Quit
			} else {
				panic(err)
			}
		default:
			if !m.textarea.Focused() {
				cmd = m.textarea.Focus()
				cmds = append(cmds, cmd)
			}
		}

		// We handle errors just like any other message
		// case errMsg:
		// 	m.err = msg
		// 	return m, nil
	}

	m.textarea, cmd = m.textarea.Update(msg)
	cmds = append(cmds, cmd)
	return m, tea.Batch(cmds...)
}

func (m model) headerView() string {
	return m.title + "\n"
}

func (m model) writeFile() error {
	_, err := m.fh.Seek(0, io.SeekStart)
	if err != nil {
		return fmt.Errorf("seek: %w", err)
	}

	m.fh.Write([]byte("# " + m.title + "\n\n"))

	_, err = m.fh.Write([]byte(m.textarea.Value()))
	if err != nil {
		return fmt.Errorf("write: %w", err)
	}

	return m.fh.Sync()
}

func (m model) View() tea.View {
	footer1 := "(ctrl+c to quit)"
	footer2 := ":-)"

	for _, message := range m.transientMsgs {
		footer2 += message.msg + ", "
	}
	footer2 = strings.TrimRight(footer2, ", ")
	if len(footer2) > m.textarea.Width() {
		footer2 = footer2[:m.textarea.Width()]
	}

	var c *tea.Cursor
	if !m.textarea.VirtualCursor() {
		c = m.textarea.Cursor()

		if c != nil {
			// Set the y offset of the cursor based on the position of the textarea
			// in the application.
			offset := lipgloss.Height(m.headerView())
			c.Y += offset
		}
	}

	f := strings.Join([]string{
		m.headerView(),
		m.textarea.View(),
		footer1,
		footer2,
	}, "\n")

	v := tea.NewView(f)
	v.Cursor = c
	return v
}