package layout

import (
	"math"

	"github.com/stevec/fancywin/internal/config"
)

type Rect struct{ Left, Top, Right, Bottom int32 }
type Point struct{ X, Y int32 }

func Resolve(work Rect, z config.Zone, gap int) Rect {
	w, h := float64(work.Right-work.Left), float64(work.Bottom-work.Top)
	r := Rect{
		Left:   work.Left + int32(math.Round(w*z.X/100)),
		Top:    work.Top + int32(math.Round(h*z.Y/100)),
		Right:  work.Left + int32(math.Round(w*(z.X+z.Width)/100)),
		Bottom: work.Top + int32(math.Round(h*(z.Y+z.Height)/100)),
	}
	g := int32(gap)
	r.Left += g
	r.Top += g
	r.Right -= g
	r.Bottom -= g
	if r.Right <= r.Left {
		r.Right = r.Left + 1
	}
	if r.Bottom <= r.Top {
		r.Bottom = r.Top + 1
	}
	return r
}

func Contains(r Rect, p Point) bool {
	return p.X >= r.Left && p.X < r.Right && p.Y >= r.Top && p.Y < r.Bottom
}

func ZoneAt(work Rect, zones []config.Zone, gap int, p Point) int {
	for i, z := range zones {
		if Contains(Resolve(work, z, gap), p) {
			return i
		}
	}
	return -1
}

func Closest(work Rect, zones []config.Zone, p Point) int {
	best, bestD := -1, math.MaxFloat64
	for i, z := range zones {
		r := Resolve(work, z, 0)
		cx, cy := float64(r.Left+r.Right)/2, float64(r.Top+r.Bottom)/2
		dx, dy := float64(p.X)-cx, float64(p.Y)-cy
		if d := dx*dx + dy*dy; d < bestD {
			best, bestD = i, d
		}
	}
	return best
}