//! The common code for `tests/lang_tests_*.rs`
use std::{
    env::{self, current_dir},
    path::{Path, PathBuf},
    process::Command,
};

use lang_tester::LangTester;
use tempfile::TempDir;

/// Controls the compile options (e.g., optimization level) used to compile
/// test code.
#[allow(dead_code)] // Each test crate picks one variant
pub enum Profile {
    Debug,
    Release,
}

pub fn main_inner(profile: Profile) {
    let tempdir = TempDir::new().expect("temp dir");
    let current_dir = current_dir().expect("current dir");
    let current_dir = current_dir.to_str().expect("current dir").to_string();
    let gcc_path = include_str!("../gcc_path");
    let gcc_path = gcc_path.trim();
    env::set_var("LD_LIBRARY_PATH", gcc_path);

    fn rust_filter(filename: &Path) -> bool {
        filename.extension().expect("extension").to_str().expect("to_str") == "rs"
    }

    #[cfg(feature="master")]
    fn filter(filename: &Path) -> bool {
        rust_filter(filename)
    }

    #[cfg(not(feature="master"))]
    fn filter(filename: &Path) -> bool {
        if let Some(filename) = filename.to_str() {
            if filename.ends_with("gep.rs") {
                return false;
            }
        }
        rust_filter(filename)
    }

    LangTester::new()
        .test_dir("tests/run")
        .test_file_filter(filter)
        .test_extract(|source| {
            let lines =
                source.lines()
                    .skip_while(|l| !l.starts_with("//"))
                    .take_while(|l| l.starts_with("//"))
                    .map(|l| &l[2..])
                    .collect::<Vec<_>>()
                    .join("\n");
            Some(lines)
        })
        .test_cmds(move |path| {
            // Test command 1: Compile `x.rs` into `tempdir/x`.
            let mut exe = PathBuf::new();
            exe.push(&tempdir);
            exe.push(path.file_stem().expect("file_stem"));
            let mut compiler = Command::new("rustc");
            compiler.args(&[
                &format!("-Zcodegen-backend={}/target/debug/librustc_codegen_gcc.so", current_dir),
                "--sysroot", &format!("{}/build_sysroot/sysroot/", current_dir),
                "-Zno-parallel-llvm",
                "-C", "link-arg=-lc",
                "-o", exe.to_str().expect("to_str"),
                path.to_str().expect("to_str"),
            ]);

            // TODO(antoyo): find a way to send this via a cli argument.
            let test_target = std::env::var("CG_GCC_TEST_TARGET");
            if let Ok(ref target) = test_target {
                compiler.args(&["--target", &target]);
                let linker = format!("{}-gcc", target);
                compiler.args(&[format!("-Clinker={}", linker)]);
                let mut env_path = std::env::var("PATH").unwrap_or_default();
                // TODO(antoyo): find a better way to add the PATH necessary locally.
                env_path = format!("/opt/m68k-unknown-linux-gnu/bin:{}", env_path);
                compiler.env("PATH", env_path);
            }

            if let Some(flags) = option_env!("TEST_FLAGS") {
                for flag in flags.split_whitespace() {
                    compiler.arg(&flag);
                }
            }
            match profile {
                Profile::Debug => {}
                Profile::Release => {
                    compiler.args(&[
                        "-C", "opt-level=3",
                        "-C", "lto=no",
                    ]);
                }
            }
            // Test command 2: run `tempdir/x`.
            if test_target.is_ok() {
                let vm_parent_dir = std::env::var("CG_GCC_VM_DIR")
                    .map(|dir| PathBuf::from(dir))
                    .unwrap_or_else(|_| std::env::current_dir().unwrap());
                let vm_dir = "vm";
                let exe_filename = exe.file_name().unwrap();
                let vm_home_dir = vm_parent_dir.join(vm_dir).join("home");
                let vm_exe_path = vm_home_dir.join(exe_filename);
                // FIXME(antoyo): panicking here makes the test pass.
                let inside_vm_exe_path = PathBuf::from("/home").join(&exe_filename);
                let mut copy = Command::new("sudo");
                copy.arg("cp");
                copy.args(&[&exe, &vm_exe_path]);

                let mut runtime = Command::new("sudo");
                runtime.args(&["chroot", vm_dir, "qemu-m68k-static"]);
                runtime.arg(inside_vm_exe_path);
                runtime.current_dir(vm_parent_dir);
                vec![
                    ("Compiler", compiler),
                    ("Copy", copy),
                    ("Run-time", runtime),
                ]
            }
            else {
                let runtime = Command::new(exe);
                vec![
                    ("Compiler", compiler),
                    ("Run-time", runtime),
                ]
            }
        })
        .run();
}