extern isFinite
import './point' as Point
import './transform' as : Transform && [object [transformPoint tp] [untransform utp] inverse]
import './anchor' as Anchor

define-macro xytransform : syntax-rules
	`[xytransform @tfm @x @y] : begin
		set [env.declarations.get [formOf x]].isParameter 0
		set [env.declarations.get [formOf y]].isParameter 0
		let [t : env.newt] `[begin \\
			set @t @x
			set @x : @x * @tfm.xx + @y * @tfm.yx + @tfm.x
			set @y : @t * @tfm.xy + @y * @tfm.yy + @tfm.y
		]

define [mix a b p] : a + (b - a) * p
define [ratio l r m] : if [l === r] 0 ((m - l) / (r - l))
define [byx a b] : a - b
define [fallback] : for [local j 0] (j < arguments.length) [inc j] : if (arguments.(j) !== nothing) : return arguments.(j)

define [closepoint p q t] : begin
	return : [Math.abs (p.x - q.x)] <= t && [Math.abs (p.y - q.y)] <= t
define [oncurveRemovable a b c t] : begin
	local xm : (a.x + c.x) / 2
	local ym : (a.y + c.y) / 2
	return : [not a.on] && b.on && [not c.on] && [not a.cubic] && [not c.cubic] && (a.x <= b.x && b.x <= c.x || a.x >= b.x && b.x >= c.x) && (a.y <= b.y && b.y <= c.y || a.y >= b.y && b.y >= c.y) && [Math.abs (b.x - xm)] <= (t / 2) && [Math.abs (b.y - ym)] <= (t / 2)

define PRECISION 1000
define [cov x] : piecewise
	[isFinite x] : return : [Math.round : x * PRECISION] / PRECISION
	true : return 0

export all : class Glyph
	public [new name] : begin
		set this.name name
		set this.unicode {}
		set this.contours {}
		set this.advanceWidth 500
		set this.cmpPriority 0
		set this.anchors {.}
		set this.gizmo : Transform.Id
		set this.dependencies {}
		set this.defaultTag null
		return nothing
	static is {.unapply [function [obj arity] [if (obj <@ Glyph) {obj} null]]}

	public [set-width w] : begin
		this.advanceWidth = w
		return this

	public [assign-unicode u] : begin
		this.unicode.push : piecewise
			([typeof u] === 'string') : u.charCodeAt 0
			true u
		return this

	public [start-from x y] : begin
		local contour {[Point.transformed this.gizmo x y true]}
		set contour.tag this.defaultTag
		this.contours.push contour
		return this
	public moveTo : public start-from

	public [line-to x y] : begin
		this.contours.((this.contours.length - 1)).push [Point.transformed this.gizmo x y true]
		return this
	public lineTo : public line-to

	public [curve-control x y] : begin
		this.contours.((this.contours.length - 1)).push [tp this.gizmo [new Point x y false]]
		return this

	public [curve-to xc yc x y] : begin
		this.contours.((this.contours.length - 1)).push [Point.transformed this.gizmo xc yc false] [Point.transformed this.gizmo x y true]
		return this
	public curveTo : public curve-to

	public [cubic-to x1 y1 x2 y2 x y] : begin
		this.contours.((this.contours.length - 1)).push
			Point.transformed this.gizmo x1 y1 false true
			Point.transformed this.gizmo x2 y2 false true
			Point.transformed this.gizmo x y true
		return this
	public cubicTo : public cubic-to

	public [reverse-last] : begin
		if [this.contours && this.contours.(this.contours.length - 1)] : begin
			this.contours.(this.contours.length - 1) = [this.contours.(this.contours.length - 1).reverse]
		return this
	public reverseLast : public reverse-last

	public [reverse-all] : begin
		if this.contours : set this.contours : this.contours.map : lambda [c] : c.reverse
		return this
	public reverseAll : public reverse-all

	public [tag-contour tag n] : begin
		if this.contours : begin
			local lastContour this.contours.(this.contours.length - 1)
			if lastContour : if tag : set lastContour.tag tag
		return this
	public [retag-contour oldtag newtag] : begin
		if this.contours : foreach [c : items-of this.contours] : if (c.tag === oldtag) : set c.tag newtag
		return this
	public [eject-contour tag] : begin
		set this.contours : this.contours.filter : lambda [c] (c.tag !== tag)
		return this
	public [depends-on glyph] : begin
		piecewise
			glyph.name : this.dependencies.push glyph.name
			glyph.dependencies : this.dependencies = [this.dependencies.concat glyph.dependencies]
		return this

	public [includeGlyph glyph copyAnchors copyWidth] : begin
		if (glyph <@ Function) : begin
			throw "\(this.name): Cannot include a function using includeGlyph. Use include instead."

		local contours glyph.contours
		local shiftx 0
		local shifty 0
		local t this
		if (this.anchors && glyph.anchors) : foreach markid [items-of [Object.keys this.anchors]] : begin
			local anchorThis this.anchors.(markid)
			local anchorThat glyph.anchors.(markid)
			if (   anchorThis && (anchorThis.type === Anchor.BASE || anchorThis.mbx !== nothing && anchorThis.mby !== nothing)
				&& anchorThat && anchorThat.type === Anchor.MARK) : begin
				set shiftx : [fallback anchorThis.mbx anchorThis.x] - anchorThat.x
				set shifty : [fallback anchorThis.mby anchorThis.y] - anchorThat.y
				# we have a mark-to-mark position
				if (anchorThat.mbx !== nothing && anchorThat.mby !== nothing) : if (anchorThis.type === Anchor.BASE)
					then : set this.anchors.(markid) : new Anchor
						* (anchorThis.x + anchorThat.mbx - anchorThat.x)
						* (anchorThis.y + anchorThat.mby - anchorThat.y)
						* Anchor.BASE
					else : set this.anchors.(markid) : new Anchor
						* anchorThis.x
						* anchorThis.y
						* anchorThis.type
						* (anchorThis.mbx + anchorThat.mbx - anchorThat.x)
						* (anchorThis.mby + anchorThat.mby - anchorThat.y)
		if contours : begin
			local newcontours {}
			foreach [contour : items-of contours] : begin
				local c {}
				set c.tag : contour.tag || glyph.tag || t.defaultTag
				foreach [point : items-of contour] : begin
					c.push : new Point (point.x + shiftx) (point.y + shifty) point.on point.cubic point.subdivided
				newcontours.push c
			set this.contours : this.contours.concat newcontours
		if (([not contours] || copyAnchors) && glyph.anchors) : begin
			foreach [k : items-of : Object.keys glyph.anchors] : set this.anchors.(k) glyph.anchors.(k)
		if (glyph.advanceWidth >= 0 && copyWidth) : set this.advanceWidth glyph.advanceWidth
		if glyph.name : this.dependencies.push glyph.name
		if glyph.dependencies : this.dependencies = [this.dependencies.concat glyph.dependencies]
		return this

	public [include component copyAnchors copyWidth] : begin
		piecewise
			(component <@ Function) : begin
				local t this.defaultTag
				if component.tag : set this.defaultTag component.tag
				component.call this copyAnchors copyWidth
				set this.defaultTag t
				return this
			(component <@ Transform) : return : this.apply-transform component copyAnchors
			(component <@ Array) : begin
				return : this.includeGlyph {.contours component} copyAnchors copyWidth
			true : begin
				return : this.includeGlyph component copyAnchors copyWidth

	public [apply-transform transform alsoAnchors] : begin
		foreach [c : items-of this.contours] : foreach [j : range 0 c.length] : set c.(j) : tp transform c.(j)
		if alsoAnchors : foreach key [items-of [Object.keys this.anchors]] : begin
			set this.anchors.(key) : Anchor.transform transform this.anchors.(key)
		return this

	public [set-anchor id type x y mbx mby] : begin
		xytransform this.gizmo x y
		if (mbx !== nothing && mby !== nothing)
		: then : begin
			xytransform this.gizmo mbx mby
			set this.anchors.(id) : new Anchor x y type mbx mby
		: else : set this.anchors.(id) : new Anchor x y type
		if (type == Anchor.MARK) : begin
			this.start-from x y
			this.start-from mbx mby
		return this