require "json"
require "option_parser"

version = "0.1"

class Window
    JSON.mapping({
        id: UInt32,
        name: String,
        wtype: {type: String, key: "type"},
        app_id: {type: String, default: ""},
        wclass: {type: String, key: "class", default: ""},
        marks: {type: Array(String), default: [] of String},
        nodes: {type: Array(Window), default: [] of Window},
        focused: {type: Bool, default: false}
    })

    def clear_nodes
        @nodes = [] of Window
    end
end

def node_loop (root : Window)
    list = [] of Window
    root.nodes.each do |node|
        if node.wtype == "con"
            list << node
        elsif !node.nodes.empty?
            list.concat node_loop node
        end
    end
    list
end

client_tree = Window.from_json(`swaymsg -t get_tree`)

if client_tree.wtype != "root"
    puts "Malformed client tree."
    exit(1)
end

window_list = node_loop client_tree

cycle = false
OptionParser.parse do |parser|
    parser.banner = "Usage: swayfocus [OPTIONS]"
    
    parser.on "-v", "--version", "Show Version" do
        puts version
        exit(0)
    end
    
    parser.on "-h", "--help", "Show Help" do
        puts parser
        exit(0)
    end

    parser.on "-p", "--print", "Print window names and exit" do
        window_list.each do |win|
            puts win.name
        end
        exit(0)
    end

    parser.on "-c", "--cycle", "Cycle through all matching windows in order, instead of selecting the first in the list" do
    	cycle = true
    end

    parser.on "-n WNAME", "--name=WNAME", "Match against window name" do |wname|
	window_list.select! {|w| w.name.includes? wname}
    end

    parser.on "-m WMARK", "--mark=WMARK", "Match against window mark" do |wmark|
    	window_list.reject! {|w| w.marks.none?{|m| m.includes? wmark}}
    end

    parser.on "-t WTYPE", "--type=WTYPE", "Match against window type (app_id for wayland, class for xwayland)" do |wtype|
    	window_list.select! {|w| w.app_id.includes?(wtype) || w.wclass.includes?(wtype)}
    end
  
    parser.invalid_option do |flag|
        STDERR.puts "#{flag} is not a valid option"
        STDERR.puts parser
        exit(1)
    end

    parser.missing_option do |flag|
    	STDERR.puts "#{flag} requires an argument"
    	STDERR.puts parser
    	exit(1)
    end
end

if window_list.empty?
    puts "No matching window."
    exit(1)
end

if cycle
    windex = window_list.index {|w| w.focused}
    if windex.nil? || windex == window_list.size - 1
        windex = -1
    end
    windex += 1
    Process.exec("swaymsg", ["[con_id=#{window_list[windex].id.to_s}]","focus"])
else
    Process.exec("swaymsg", ["[con_id=#{window_list[0].id.to_s}]","focus"])
end