// Generates AppIcon.iconset — Claude's asterisk above a rack of overcoats, on
// Claude's own coral. The wardrobe is the app in one picture: several coats to
// pick between, one currently worn.
//
// Everything is drawn from vector paths here rather than exported from a
// design tool, so a size can be tuned independently (small sizes need fatter
// strokes than a straight downscale gives) and nothing binary but the derived
// .icns is committed. Deliberately not derived from Claude's own icon assets.
//
// Usage:
//   swift icon/generate-icon.swift icon/AppIcon.iconset
//   iconutil -c icns icon/AppIcon.iconset -o icon/AppIcon.icns
//   rm -rf icon/AppIcon.iconset
import Cocoa

// Claude's coral and cloud, plus tints of each for depth. The lapel is a
// lighter grey than the coat and the back coats are darker corals — tone
// separation survives downscaling, where outlines don't.
private enum Palette {
    static func rgb(_ hex: UInt32) -> NSColor {
        NSColor(srgbRed: CGFloat((hex >> 16) & 255) / 255, green: CGFloat((hex >> 8) & 255) / 255,
                blue: CGFloat(hex & 255) / 255, alpha: 1)
    }
    static let tile = rgb(0xD9_77_57)
    static let coat = rgb(0xF0_EE_E6)
    static let lapel = rgb(0xB3_AA_97)
    static let pocket = rgb(0xB8_AF_9C)
    static let backLeft = rgb(0x8A_3E_2A)
    static let backLeftPocket = rgb(0x6E_35_24)
    static let backRight = rgb(0xB4_61_4A)
    static let backRightPocket = rgb(0x94_4A_34)
}

private func p(_ x: CGFloat, _ y: CGFloat) -> NSPoint { NSPoint(x: x, y: y) }

// MARK: - Shapes, drawn in a 100x100 space with y pointing down

// Eight rays of slightly uneven length, a few degrees off the compass points —
// a mechanically regular asterisk reads as a snowflake. Wider than tall, so it
// doesn't look like it's standing on end.
private func asterisk() -> NSBezierPath {
    let centre = p(50, 24)
    let tips = [p(65, 24), p(59, 33.3), p(49.5, 38.5), p(40.8, 32.6),
                p(35, 23.7), p(40.8, 14.5), p(50.2, 9.8), p(58.6, 15.1)]
    let path = NSBezierPath()
    for tip in tips { path.move(to: centre); path.line(to: tip) }
    path.lineWidth = 5.6
    path.lineCapStyle = .round
    return path
}

// One coat in its own 40x44 box, so the three can be placed at different
// scales and angles. The centre split is a true hole, so the tile shows through.
private func coatBody() -> NSBezierPath {
    let b = NSBezierPath()
    b.move(to: p(16, 2))
    b.curve(to: p(3, 6.5), controlPoint1: p(12, 2.5), controlPoint2: p(6, 4))
    b.curve(to: p(2.5, 42), controlPoint1: p(1.5, 16), controlPoint2: p(1.5, 30))
    b.line(to: p(37.5, 42))
    b.curve(to: p(37, 6.5), controlPoint1: p(38.5, 30), controlPoint2: p(38.5, 16))
    b.curve(to: p(24, 2), controlPoint1: p(34, 4), controlPoint2: p(28, 2.5))
    b.line(to: p(20, 26))
    b.close()
    b.appendRect(NSRect(x: 19.15, y: 26, width: 1.7, height: 16))
    b.windingRule = .evenOdd
    return b
}

// One connected band round the neck rather than two tabs on the shoulders,
// dipping at centre where the lapel opening begins. Its top corners sit at
// x15/x25 so the lapels cover them — any further out and they poke through as
// spikes either side of the neck.
private func coatCollar() -> NSBezierPath {
    let c = NSBezierPath()
    c.move(to: p(15, -1.6)); c.line(to: p(25, -1.6))
    c.line(to: p(29, 2.6)); c.line(to: p(21.6, 2.6))
    c.line(to: p(20, 1)); c.line(to: p(18.4, 2.6))
    c.line(to: p(11, 2.6))
    c.close()
    return c
}

// Notch lapels, each one shape running from the collar's outer corner down to
// the button point. The notch sits at (12.5, 8) — pulled down and outward
// deliberately, because nearer the inner edge it pinches the polygon to a
// hairline and the lapel renders as two separate triangles.
private func coatLapels() -> NSBezierPath {
    let l = NSBezierPath()
    l.move(to: p(15, -1.6)); l.line(to: p(10.5, 3.5)); l.line(to: p(12.5, 8))
    l.line(to: p(9, 14)); l.line(to: p(20, 26)); l.close()
    l.move(to: p(25, -1.6)); l.line(to: p(29.5, 3.5)); l.line(to: p(27.5, 8))
    l.line(to: p(31, 14)); l.line(to: p(20, 26)); l.close()
    return l
}

// Filled marks, not holes — a hole would show whichever coat is behind it.
private func coatPockets() -> NSBezierPath {
    let path = NSBezierPath()
    path.appendRect(NSRect(x: 6.5, y: 22, width: 9, height: 1.7))
    path.appendRect(NSRect(x: 24.5, y: 22, width: 9, height: 1.7))
    return path
}

// A hairline along the lapel edges separating the grey lapel from the tile
// showing through the opening. Deliberately fine: a detail for 128px and up.
// Thickening it to survive smaller sizes only blurs the lapel edge, because at
// this diagonal a one-pixel stroke covers a fraction of each pixel it crosses.
private func coatOpeningBorder() -> NSBezierPath {
    let path = NSBezierPath()
    path.move(to: p(15, -1.6)); path.line(to: p(20, 26)); path.line(to: p(25, -1.6))
    path.lineWidth = 0.7
    path.lineJoinStyle = .round
    path.lineCapStyle = .round
    return path
}

private func placed(_ path: NSBezierPath, x: CGFloat, y: CGFloat,
                    rotation: CGFloat, scale: CGFloat) -> NSBezierPath {
    let transform = NSAffineTransform()
    transform.translateX(by: x, yBy: y)
    if rotation != 0 { transform.rotate(byDegrees: rotation) }
    transform.scale(by: scale)
    let copy = path.copy() as! NSBezierPath
    copy.transform(using: transform as AffineTransform)
    return copy
}

// Each coat is finished before the next is laid over it. Drawing all three
// bodies and then all three sets of details would put the back coats' collars
// and pockets on top of the front coat.
private func drawCoat(x: CGFloat, y: CGFloat, rotation: CGFloat, scale: CGFloat,
                      body: NSColor, pocket: NSColor, lapel: NSColor? = nil) {
    body.setFill()
    placed(coatBody(), x: x, y: y, rotation: rotation, scale: scale).fill()
    placed(coatCollar(), x: x, y: y, rotation: rotation, scale: scale).fill()
    if let lapel {
        lapel.setFill()
        placed(coatLapels(), x: x, y: y, rotation: rotation, scale: scale).fill()
        body.setStroke()
        let border = placed(coatOpeningBorder(), x: x, y: y, rotation: rotation, scale: scale)
        border.lineWidth = 0.7 * scale
        border.stroke()
    }
    pocket.setFill()
    placed(coatPockets(), x: x, y: y, rotation: rotation, scale: scale).fill()
}

private func drawIcon() {
    Palette.tile.setFill()
    NSBezierPath(roundedRect: NSRect(x: 0, y: 0, width: 100, height: 100),
                 xRadius: 22, yRadius: 22).fill()

    Palette.coat.setStroke()
    asterisk().stroke()

    drawCoat(x: 11, y: 50, rotation: -8, scale: 0.78,
             body: Palette.backLeft, pocket: Palette.backLeftPocket)
    drawCoat(x: 60, y: 47, rotation: 8, scale: 0.78,
             body: Palette.backRight, pocket: Palette.backRightPocket)
    drawCoat(x: 31.5, y: 44, rotation: 0, scale: 0.92,
             body: Palette.coat, pocket: Palette.pocket, lapel: Palette.lapel)
}

// MARK: - Rendering

// Renders at exact pixel dimensions via an explicit NSBitmapImageRep rather
// than NSImage.lockFocus() — lockFocus rasterizes at the *main screen's*
// backing scale factor, which would silently double every size on a Retina
// display instead of producing the exact px asked for.
private func renderIcon(pixels: Int) -> Data {
    let side = CGFloat(pixels)
    guard let rep = NSBitmapImageRep(
        bitmapDataPlanes: nil, pixelsWide: pixels, pixelsHigh: pixels,
        bitsPerSample: 8, samplesPerPixel: 4, hasAlpha: true, isPlanar: false,
        colorSpaceName: .deviceRGB, bytesPerRow: 0, bitsPerPixel: 0
    ) else { fatalError("could not create bitmap rep") }
    rep.size = NSSize(width: side, height: side)

    NSGraphicsContext.saveGraphicsState()
    NSGraphicsContext.current = NSGraphicsContext(bitmapImageRep: rep)
    NSGraphicsContext.current?.imageInterpolation = .high

    // The shapes are authored y-down, the way the drawing reads; flip once
    // here rather than mirroring every coordinate.
    let flip = NSAffineTransform()
    flip.translateX(by: 0, yBy: side)
    flip.scaleX(by: side / 100, yBy: -side / 100)
    flip.concat()

    drawIcon()

    NSGraphicsContext.restoreGraphicsState()

    guard let png = rep.representation(using: .png, properties: [:]) else {
        fatalError("failed to encode PNG at \(pixels)px")
    }
    return png
}

let sizes: [(name: String, px: Int)] = [
    ("icon_16x16", 16), ("icon_16x16@2x", 32),
    ("icon_32x32", 32), ("icon_32x32@2x", 64),
    ("icon_128x128", 128), ("icon_128x128@2x", 256),
    ("icon_256x256", 256), ("icon_256x256@2x", 512),
    ("icon_512x512", 512), ("icon_512x512@2x", 1024),
]

let outDir = CommandLine.arguments.count > 1 ? CommandLine.arguments[1] : "AppIcon.iconset"
try? FileManager.default.createDirectory(atPath: outDir, withIntermediateDirectories: true)
for (name, px) in sizes {
    let path = "\(outDir)/\(name).png"
    try? renderIcon(pixels: px).write(to: URL(fileURLWithPath: path))
    print("wrote \(path)")
}