package selection

import (
	"github.com/bnema/nefergui"

	"github.com/bnema/nefercap/internal/ports"
)

// view draws the scene. Geometry goes through Node.Rect, so no CSS strings
// are built per frame; classes come from the embedded stylesheet. Boxes with no
// area are not emitted at all, so an idle surface is one dim box plus the
// header and footer, and no empty chip is painted.
func view(f *nefergui.Frame, m *model) {
	m.syncMode() // a Tab on another overlay redraws this one
	m.refreshFooter()
	root := f.Root(nefergui.Class("root"))
	st := root.Stack(nefergui.Class("scene"))
	if drawsBackdrop(m) {
		// The frozen screen, scaled to fill the logical surface.
		box := st.Box(nefergui.Key("backdrop"), nefergui.Class("backdrop")).Rect(0, 0, float64(m.w), float64(m.h))
		box.Image(m.backdrop)
	}
	s := m.scene()
	for i, r := range s.dim {
		box(st, dimKeys[i], "dim", r)
	}
	for i, r := range s.grid {
		box(st, gridKeys[i], "grid", r)
	}
	for i, r := range s.edges {
		box(st, edgeKeys[i], "edge", r)
	}
	if n := tag(st, "label", s.label); n.ok {
		n.node.Text(m.label.text)
	}
	if n := tag(st, "badge", s.badge); n.ok {
		n.node.Text(badgeText(m.mode))
	}
	if n := tag(st, "header", s.header); n.ok {
		n.node.Text(m.header)
	}
	if n := tag(st, "footer", s.footer); n.ok {
		n.node.Text(m.footerText)
	}
}

// drawsBackdrop: a screenshot selection shows the frozen screen; a recording
// selects on the live screen.
func drawsBackdrop(m *model) bool {
	return m.backdrop != nil && m.mode == ports.Screenshot && m.w > 0 && m.h > 0
}

type tagged struct {
	node nefergui.Node
	ok   bool
}

func box(st nefergui.Node, key, class string, r frect) {
	if r.w > 0 && r.h > 0 {
		st.Box(nefergui.Key(key), nefergui.Class(class)).Rect(r.x, r.y, r.w, r.h)
	}
}

func tag(st nefergui.Node, key string, r frect) tagged {
	if r.w <= 0 || r.h <= 0 {
		return tagged{}
	}
	return tagged{st.Box(nefergui.Key(key), nefergui.Class("tag")).Rect(r.x, r.y, r.w, r.h), true}
}

// Static keys avoid building identity strings per frame.
var (
	dimKeys  = [4]string{"dim0", "dim1", "dim2", "dim3"}
	gridKeys = [6]string{"grid0", "grid1", "grid2", "grid3", "grid4", "grid5"}
	edgeKeys = [4]string{"edge0", "edge1", "edge2", "edge3"}
)