use std::io::{BufRead, BufReader};
use std::process::{Command, Stdio};
use cargo_metadata::{PackageId, Target};
use serde::{Deserialize, Serialize};
// Use an alternative profile so clean-building is "sandboxed" to this tool
const CARGO_CUSOTM_PROFILE: [&str; 2] = ["--config", r#"profile.depwiz.inherits="dev""#];
/// See https://docs.rs/cargo/latest/cargo/core/compiler/enum.CompileMode.html
/// These are the only two cases we are interested in
#[derive(Clone, Debug, Serialize, Deserialize)]
#[serde(rename_all = "kebab-case")]
enum Mode {
    Build,
    RunCustomBuild,
}
/// See https://docs.rs/cargo/latest/cargo/util/machine_message/struct.TimingInfo.html
#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct Message {
    reason: String,
    package_id: PackageId,
    target: Target,
    mode: Mode,
    duration: f64,
    rmeta_time: Option<f64>,
}
pub fn generate() -> Vec<Message> {
    // TODO: `cargo build --timings=json` seems to only work on a clean build
    Command::new("cargo")
        .arg("clean")
        .args(CARGO_CUSOTM_PROFILE)
        .args(&["--profile", "depwiz"])
        .stdout(Stdio::inherit())
        .stderr(Stdio::inherit())
        .output()
        .unwrap();
    let timings_ouput = Command::new("cargo")
        .arg("build")
        .args(CARGO_CUSOTM_PROFILE)
        .args(&[
            "--profile",
            "depwiz",
            "-Zunstable-options",
            "--timings=json",
        ])
        .stderr(Stdio::inherit())
        .output()
        .unwrap();
    let mut timings = Vec::new();
    let mut timings_buffer = BufReader::new(timings_ouput.stdout.as_slice());
    let mut message_buffer = Vec::new();
    loop {
        timings_buffer
            .read_until(b'\n', &mut message_buffer)
            .unwrap();
        let json_message: Message = match serde_json::from_slice(&message_buffer) {
            Ok(message) => message,
            Err(err) => {
                use serde_json::error::Category;
                match err.classify() {
                    Category::Eof => break,
                    Category::Data => todo!(
                        "JSON object not properly handled, got `{err:?}` for message: `{}`",
                        String::from_utf8(message_buffer.clone()).unwrap()
                    ),
                    _ => {
                        panic!("Unexpected error while parsing: {err:?}");
                    }
                }
            }
        };
        // Make sure it's actually a timings message
        assert_eq!(json_message.reason, "timing-info");
        timings.push(json_message);
        message_buffer.clear();
    }
    timings
}

mod timings;

    let mut cmd = MetadataCommand::new();
    let package_graph = PackageGraph::from_command(&mut cmd).unwrap();

    dbg!(timings::generate());
    let mut metadata_cmd = MetadataCommand::new();
    let package_graph = PackageGraph::from_command(&mut metadata_cmd).unwrap();

cargo_metadata = "0.18.1"

serde = { version = "1.0.198", features = ["serde_derive"] }
serde_json = "1.0.116"

 "cargo_metadata",

 "serde",
 "serde_json",

version = "1.0.197"

version = "1.0.198"

checksum = "3fb1c873e1b9b056a4dc4c0c198b24c3ffa059243875552b2bd0933b1aee4ce2"

checksum = "9846a40c979031340571da2545a4e5b7c4163bdae79b301d5f86d03979451fcc"

version = "1.0.197"

version = "1.0.198"

checksum = "7eb0b34b42edc17f6b7cac84a52a1c5f0e1bb2227e997ca9011ea3dd34e8610b"

checksum = "e88edab869b01783ba905e7d0153f9fc1a6505a96e4ad3018011eedb838566d9"

version = "1.0.115"

version = "1.0.116"

checksum = "12dc5c46daa8e9fdf4f5e71b6cf9a53f2487da0e86e55808e2d35539666497dd"

checksum = "3e17db7126d17feb94eb3fad46bf1a96b034e8aacbc2e775fe81505f8b0b2813"