package main

import (
	"fmt"

	"git.sentinel65x.com/dave/gary/debugger/memory"
	tea "github.com/charmbracelet/bubbletea"
	lip "github.com/charmbracelet/lipgloss"
)

func UI(mem *memory.Memory) error {
	initial := debugger{
		width:     0,
		height:    0,
		mem:       mem,
		statusMsg: "Loading...",
	}
	initial.hex = NewHexView(mem, initial.commitWrites)
	initial.hex.AddrStyle = text
	initial.hex.ZeroStyle = faintText
	initial.hex.HexStyle = text

	p := tea.NewProgram(initial)
	if _, err := p.Run(); err != nil {
		return err
	}
	return nil
}

var (
	amber = lip.Color("#ffb00")
	slate = lip.Color("235")
	text  = lip.NewStyle().
		Foreground(amber).
		Background(slate).
		BorderForeground(amber).
		BorderBackground(slate).
		Border(lip.NormalBorder(), false, false, false, false)
	faintText = text.Faint(true)

	box = lip.NewStyle().
		Border(lip.NormalBorder()).
		BorderForeground(amber).
		BorderBackground(slate).
		Padding(1, 2)
)

type msgMemoryChanged struct {
	start, count int
}

type msgErr struct {
	err error
}

type msgUpdateStatus struct {
	status string
}

type debugger struct {
	width     int
	height    int
	mem       *memory.Memory
	hex       HexView
	lastErr   error
	statusMsg string
}

func (m debugger) Init() tea.Cmd {
	loads := m.readFullMemoryCmds()
	ret := make([]tea.Cmd, 0, (len(loads)*2)+1)
	for i, c := range loads {
		ret = append(ret, staticMsg(msgUpdateStatus{fmt.Sprintf("Loading block %d/%d", i+1, len(loads))}), c)
	}
	ret = append(ret, staticMsg(msgUpdateStatus{"Load complete."}))
	return tea.Sequence(ret...)
}

func (m debugger) readFullMemory() tea.Cmd {
	return tea.Sequence(m.readFullMemoryCmds()...)
}

func (m debugger) readFullMemoryCmds() []tea.Cmd {
	var ret []tea.Cmd
	for i := 0; i < m.mem.Len(); i += 32 * 1024 {
		ret = append(ret, m.readMemory(i, 32*1024))
	}
	return ret
}

func (m debugger) readMemory(start, count int) tea.Cmd {
	return func() tea.Msg {
		if err := m.mem.Refresh(start, count); err != nil {
			return msgErr{fmt.Errorf("loading region 0x%x+%x: %w", start, count, err)}
		}
		return msgMemoryChanged{start, count}
	}
}

func staticMsg(msg tea.Msg) tea.Cmd {
	return func() tea.Msg {
		return msg
	}
}

func (m debugger) commitWrites() tea.Cmd {
	return tea.Sequence(
		staticMsg(msgUpdateStatus{"Writing..."}),
		func() tea.Msg {
			if err := m.mem.Commit(); err != nil {
				return msgUpdateStatus{fmt.Sprintf("Write failed: %v", err)}
			}
			return msgUpdateStatus{"Writes complete."}
		},
		m.readFullMemory(),
	)
}

func (m debugger) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.WindowSizeMsg:
		m.width = msg.Width
		m.height = msg.Height
		var cmd tea.Cmd
		m.hex, cmd = m.hex.Update(HexViewSetHeight{m.height - box.GetVerticalFrameSize() - 1})
		return m, cmd
	case tea.KeyMsg:
		switch msg.String() {
		case "ctrl+c", "q":
			return m, tea.Quit
		case "r":
			start, end := m.hex.VisibleBytes()
			return m, m.readMemory(start, end-start)
		case "R":
			return m, m.readFullMemory()
		}
	case msgErr:
		m.lastErr = msg.err
		return m, nil
	case msgUpdateStatus:
		m.statusMsg = msg.status
	}
	var cmd tea.Cmd
	m.hex, cmd = m.hex.Update(msg)
	return m, cmd
}

// func (m debugger) values(addr int) string {
// 	var v [4]byte
// 	copy(v[:], m.vram[addr:])
// 	var out strings.Builder
// 	out.WriteString(text.Render("Bin: "))
// 	out.WriteString(renderBytes(v[:], "%08b", "_"))
// 	out.WriteByte('\n')
// 	out.WriteString(text.Render("Hex: "))
// 	out.WriteString(renderBytes(v[:], "%02x", "_"))
// 	out.WriteByte('\n')
// 	out.WriteString(text.Render("Dec: "))
// 	out.WriteString(faintText.Render("["))
// 	out.WriteString(dimZero(fmt.Sprintf("%3d", v[0])))
// 	out.WriteString(faintText.Render("] ["))
// 	out.WriteString(dimZero(fmt.Sprintf("%5d", binary.BigEndian.Uint16(v[:]))))
// 	out.WriteString(faintText.Render("] ["))
// 	out.WriteString(dimZero(fmt.Sprintf("%10d", binary.BigEndian.Uint32(v[:]))))
// 	out.WriteString(faintText.Render("]"))

// 	return out.String()
// }

func (m debugger) View() string {
	if m.width < 80 || m.height < 20 {
		return lip.Place(m.width, m.height, lip.Center, lip.Center, "Please embiggen your terminal")
	}

	hex := box.Render(m.hex.View())

	barText := text.Reverse(true) //.Height(1)

	topLeft := barText.Bold(true).PaddingLeft(1).Render("Addr: ")
	topLeft += barText.Render(fmt.Sprintf("0x%x (%d)", m.hex.SelectedAddr(), m.hex.SelectedAddr()))
	topRight := barText.PaddingRight(1).Render(m.statusMsg)
	title := barText.Padding(0, 1).Bold(true).Render("GARY Debugger")

	sideWidth := max(lip.Width(topLeft), lip.Width(topRight))
	titleWidth := m.width - 2*sideWidth
	topLeft = barText.Width(sideWidth).Align(lip.Left).Render(topLeft)
	topRight = barText.Width(sideWidth).Align(lip.Right).Render(topRight)
	title = barText.Width(titleWidth).Align(lip.Center).Render(title)

	status := lip.JoinHorizontal(lip.Top, topLeft, title, topRight)

	all := lip.JoinVertical(lip.Center, status, hex)
	return all
}