use std::process::Command;
use std::str;
use json;
use json::JsonValue;

enum SwayOutput {
    Disabled {
        name: String,
    },
    Enabled {
        name: String,
        width: i32,
        height: i32,
        x: i32,
        y: i32,
    }
}
fn main() {
    let output = Command::new("swaymsg")
                     .arg("-t")
                     .arg("get_outputs")
                     .output()
                     .expect("Failed to execute command");
    let s = str::from_utf8(&output.stdout).unwrap();

    let mut outputs: Vec<SwayOutput> = Vec::new();

    let json = json::parse(s).unwrap();

    // TODO I think there is a better alternative syntax to match here.
    let json_outputs = match json {
        JsonValue::Array(vec) => vec,
        _ => panic!("json was not an array")
    };

    let size = json_outputs.len();
    if size == 1 {
        // If there is 1 output, use it.
        let json_output = &json_outputs[0];
        let name = &json_output["name"];
        let mode = &json_output["modes"][0];
        outputs.push(SwayOutput::Enabled {
            name: name.to_string(),
            width: mode["width"].as_i32().unwrap(),
            height: mode["height"].as_i32().unwrap(),
            x: 0,
            y: 0,
        });
    } else {
        let dell_option:Option<&JsonValue> = json_outputs.iter()
            .find( |json_output| json_output["serial"].to_string() == "CFV9N99T0Y0U");
        if dell_option.is_some() {
            // The Dell on my desk is attached. Use it, and disable others.
            let dell = dell_option.unwrap();
            outputs.push(SwayOutput::Enabled {
                name: dell["name"].to_string(),
                width: 1920,
                height: 1200,
                x: 0,
                y: 0
            });
            json_outputs.iter()
                .filter( |json_output| {
                    json_output["serial"].to_string() != "CFV9N99T0Y0U"
                })
                .for_each( |json_output| {
                    outputs.push(SwayOutput::Disabled {
                        name: json_output["name"].to_string()
                    });
                });
        } else {
            println!("unknown state, do nothing")
        }
    }

    // TODO do all enables then all disables.
    // TODO if there are only disables then do nothing.
    for output in &outputs {
        match output {
            SwayOutput::Disabled { name } => {
                println!("swaymsg output {} disabled", name);
                // TODO run
            },
            SwayOutput::Enabled { name, width, height, x, y } => {
                println!(
                    "swaymsg output {} enable dpms on mode {}x{} pos {} {}",
                    name, width, height, x, y);
                // TODO run
            }
        }
    }

}