// Package ui is haul's desktop GUI: a connection window backed by ~/.ssh/config
// (plus ad-hoc quick connect), and a two-pane local/remote file browser per
// connected host.
//
// The rule the whole package follows: Fyne widgets are only ever touched from
// the UI thread. Every SFTP call — listing a directory, transferring, deleting
// — runs on its own goroutine and comes back through fyne.Do. A GUI that blocks
// its event loop on a network round-trip is exactly the thing that makes an
// SFTP client feel slow, and remote round-trips are the common case here.
package ui

import (
	"image/color"

	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/app"
	"fyne.io/fyne/v2/theme"
)

// Run starts the GUI and blocks until the user quits.
func Run() error {
	a := app.NewWithID("space.apointless.haul")
	a.Settings().SetTheme(&haulTheme{base: theme.DefaultTheme()})
	newConnectWindow(a).showAndRun()
	return nil
}

// haulTheme keeps the high-contrast, low-light-friendly look haul had as a TUI:
// a near-black background, bright text, and a clearly visible selection. It also
// tightens padding, because a file manager lives or dies on how many rows fit on
// screen.
type haulTheme struct{ base fyne.Theme }

var (
	bgDark        = color.NRGBA{R: 0x11, G: 0x13, B: 0x18, A: 0xff}
	panelDark     = color.NRGBA{R: 0x1a, G: 0x1d, B: 0x24, A: 0xff}
	inputDark     = color.NRGBA{R: 0x0b, G: 0x0d, B: 0x11, A: 0xff}
	fgDark        = color.NRGBA{R: 0xf0, G: 0xf3, B: 0xf8, A: 0xff}
	mutedDark     = color.NRGBA{R: 0x8b, G: 0x93, B: 0xa1, A: 0xff}
	separatorDark = color.NRGBA{R: 0x2c, G: 0x31, B: 0x3a, A: 0xff}
	accent        = color.NRGBA{R: 0x4c, G: 0x9a, B: 0xff, A: 0xff}
	selectionDark = color.NRGBA{R: 0x1e, G: 0x3f, B: 0x66, A: 0xff}
	hoverDark     = color.NRGBA{R: 0x25, G: 0x2a, B: 0x33, A: 0xff}
)

func (t *haulTheme) Color(n fyne.ThemeColorName, v fyne.ThemeVariant) color.Color {
	if v == theme.VariantLight {
		// In light mode only the accent is overridden; the stock light palette
		// already has the contrast this theme is trying to buy back in the dark.
		if n == theme.ColorNamePrimary {
			return accent
		}
		return t.base.Color(n, v)
	}

	switch n {
	case theme.ColorNameBackground:
		return bgDark
	case theme.ColorNameForeground:
		return fgDark
	case theme.ColorNameButton, theme.ColorNameMenuBackground, theme.ColorNameOverlayBackground:
		return panelDark
	case theme.ColorNameHeaderBackground:
		return panelDark
	case theme.ColorNameInputBackground:
		return inputDark
	case theme.ColorNamePrimary:
		return accent
	case theme.ColorNameSelection:
		return selectionDark
	case theme.ColorNameHover:
		return hoverDark
	case theme.ColorNameSeparator:
		return separatorDark
	case theme.ColorNamePlaceHolder, theme.ColorNameDisabled:
		return mutedDark
	case theme.ColorNameScrollBar:
		return separatorDark
	}
	return t.base.Color(n, v)
}

func (t *haulTheme) Font(s fyne.TextStyle) fyne.Resource { return t.base.Font(s) }

func (t *haulTheme) Icon(n fyne.ThemeIconName) fyne.Resource { return t.base.Icon(n) }

func (t *haulTheme) Size(n fyne.ThemeSizeName) float32 {
	switch n {
	case theme.SizeNamePadding:
		return 3 // stock is 4; buys roughly one extra row per screenful
	case theme.SizeNameInnerPadding:
		return 6
	case theme.SizeNameSeparatorThickness:
		return 1
	}
	return t.base.Size(n)
}