package ui

import (
	"fmt"
	"strings"

	gemlog "git.travisshears.com/travisshears/gemlog-cli/gemlog"
	"github.com/charmbracelet/bubbles/viewport"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"
	"github.com/muesli/reflow/wordwrap"
)

type EntryPageModel struct {
	entry    gemlog.GemlogEntry
	ready    bool
	viewport viewport.Model
}

func initialEntryPageModel() EntryPageModel {
	return EntryPageModel{}
}

func wrapGemtxt(gemtxt string, width int) string {
	return wordwrap.String(gemtxt, width)
}

func (m EntryPageModel) Update(msg tea.Msg, active bool, ctx *context) (EntryPageModel, tea.Cmd) {
	var (
		cmd  tea.Cmd
		cmds []tea.Cmd
	)
	switch msg := msg.(type) {
	case GemLogLoaded:
		m.entry = msg.Log
		m.viewport.SetContent(wrapGemtxt(m.entry.Gemtxt, m.viewport.Width))
	case tea.KeyMsg:
		if !active {
			return m, nil
		}
		switch msg.String() {
		case "left", "h":
			cmd := func() tea.Msg {
				return SwitchPages{Page: EntryList}
			}
			return m, cmd
		}
	case tea.WindowSizeMsg:
		headerHeight := lipgloss.Height(m.headerView("loading slug..."))
		footerHeight := lipgloss.Height(m.footerView())
		verticalMarginHeight := headerHeight + footerHeight

		if !m.ready {
			// Since this program is using the full size of the viewport we
			// need to wait until we've received the window dimensions before
			// we can initialize the viewport. The initial dimensions come in
			// quickly, though asynchronously, which is why we wait for them
			// here.

			m.viewport = viewport.New(msg.Width, msg.Height-verticalMarginHeight)
			m.viewport.YPosition = headerHeight
			m.viewport.SetContent(wrapGemtxt(m.entry.Gemtxt, msg.Width))
			m.ready = true
		} else {
			m.viewport.Width = msg.Width
			m.viewport.Height = msg.Height - verticalMarginHeight
		}
	}

	// Handle keyboard and mouse events in the viewport
	m.viewport, cmd = m.viewport.Update(msg)
	cmds = append(cmds, cmd)
	return m, tea.Batch(cmds...)

}

func (m EntryPageModel) View() string {
	if !m.ready {
		return "\n  Initializing..."
	}

	return fmt.Sprintf("%s\n%s\n%s", m.headerView(m.entry.Slug), m.viewport.View(), m.footerView())
}

var (
	titleStyle = func() lipgloss.Style {
		b := lipgloss.RoundedBorder()
		b.Right = "├"
		return lipgloss.NewStyle().BorderStyle(b).Padding(0, 1)
	}()

	infoStyle = func() lipgloss.Style {
		b := lipgloss.RoundedBorder()
		b.Left = "┤"
		return titleStyle.BorderStyle(b)
	}()
)

func (m EntryPageModel) headerView(slug string) string {
	title := titleStyle.Render(slug)
	line := strings.Repeat("─", max(0, m.viewport.Width-lipgloss.Width(title)))
	return lipgloss.JoinHorizontal(lipgloss.Center, title, line)
}

func (m EntryPageModel) footerView() string {
	info := infoStyle.Render(fmt.Sprintf("%3.f%%", m.viewport.ScrollPercent()*100))
	line := strings.Repeat("─", max(0, m.viewport.Width-lipgloss.Width(info)))
	return lipgloss.JoinHorizontal(lipgloss.Center, line, info)
}

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}