import Foundation

/// Subset of colors.toml that the Swift shell actually uses.
struct LayersColors {
    var alphaFocusedHovered: CGFloat = 1.0
    var alphaPartial: CGFloat = 0.5
    var alphaIdle: CGFloat = 0.1

    /// Locate the plugin root containing `resources/colors.toml`.
    /// The Layers.app bundle lives at `<plugin_root>/bin/Layers.app`, so climb two levels.
    static func pluginRoot() -> String {
        let appPath = Bundle.main.bundlePath as NSString
        let binDir = appPath.deletingLastPathComponent as NSString
        return binDir.deletingLastPathComponent
    }

    static func load() -> LayersColors {
        var result = LayersColors()
        let path = (pluginRoot() as NSString)
            .appendingPathComponent("resources")
            .appending("/colors.toml")
        guard let src = try? String(contentsOfFile: path, encoding: .utf8) else {
            return result
        }
        let flat = flatten(src)
        if let v = flat["window.alpha_focused_hovered"] as Double? { result.alphaFocusedHovered = CGFloat(v) }
        if let v = flat["window.alpha_partial"]          as Double? { result.alphaPartial        = CGFloat(v) }
        if let v = flat["window.alpha_idle"]             as Double? { result.alphaIdle           = CGFloat(v) }
        return result
    }

    /// Minimal key=value extractor for the flat subset we care about.
    /// Returns dotted "section.key" → numeric value.
    private static func flatten(_ source: String) -> [String: Double] {
        var out: [String: Double] = [:]
        var section = ""
        for rawLine in source.split(separator: "\n", omittingEmptySubsequences: false) {
            let line = String(rawLine).trimmingCharacters(in: .whitespaces)
            if line.isEmpty || line.hasPrefix("#") { continue }
            if line.hasPrefix("[") && line.hasSuffix("]") {
                section = String(line.dropFirst().dropLast()).trimmingCharacters(in: .whitespaces)
                continue
            }
            guard let eq = line.firstIndex(of: "=") else { continue }
            let key = line[..<eq].trimmingCharacters(in: .whitespaces)
            let rawValue = String(line[line.index(after: eq)...]).trimmingCharacters(in: .whitespaces)
            let commentStripped = rawValue.split(separator: "#", maxSplits: 1).first.map(String.init) ?? rawValue
            let value = commentStripped.trimmingCharacters(in: .whitespaces)
            if value.hasPrefix("\"") { continue }
            if let d = Double(value) {
                out["\(section).\(key)"] = d
            }
        }
        return out
    }
}