// SPDX-FileCopyrightText: 2026 Milovann Yanatchkov
// SPDX-License-Identifier: MIT

//! cli end-to-end (plan 3, S5): `bimr-cli build` on the wall corpus
//! produces the compact BIMR source — master's format, with the
//! documented self-reference fix (`Wall(l1, …)` not `Wall(w1, …)`).

use std::fs;
use std::path::PathBuf;
use std::process::Command;

/// Master's checked-in ifcx artifact for the corpus — the byte-parity target.
const EXPECTED_IFCX: &str = include_str!("../../samples/bimr/wall.ifcx");

/// Per-user, cargo-managed temp dir — never the shared /tmp (sticky-bit
/// collisions across users, see the PermissionDenied incident).
fn tmp(name: &str) -> PathBuf {
    PathBuf::from(env!("CARGO_TARGET_TMPDIR")).join(name)
}

fn run_build(sample: &str, output: &PathBuf) -> Result<String, String> {
    let root = env!("CARGO_MANIFEST_DIR");
    let input = PathBuf::from(root).join("../samples/bimr").join(sample);
    let out = Command::new(env!("CARGO_BIN_EXE_bimr-cli"))
        .args([
            "build",
            input.to_str().expect("utf8 path"),
            "--output",
            output.to_str().expect("utf8 path"),
        ])
        .output()
        .map_err(|e| format!("spawn: {e}"))?;
    if !out.status.success() {
        return Err(format!(
            "bimr-cli failed: {}",
            String::from_utf8_lossy(&out.stderr)
        ));
    }
    fs::read_to_string(output).map_err(|e| format!("read output: {e}"))
}

#[test]
fn build_wall_bimr_emits_master_ifcx() {
    let content = run_build("wall.bimr", &tmp("wall_out.ifcx")).expect("build ok");
    assert_eq!(content, EXPECTED_IFCX);
}

#[test]
fn build_rejects_unknown_constructors_cleanly() {
    let sample = tmp("reject.bimr");
    fs::write(&sample, "x = Frob(p1)\n").expect("write sample");
    let out = Command::new(env!("CARGO_BIN_EXE_bimr-cli"))
        .args(["build", sample.to_str().expect("utf8")])
        .output()
        .expect("spawn");
    assert!(!out.status.success(), "List must be rejected");
    let stderr = String::from_utf8_lossy(&out.stderr);
    assert!(
        stderr.contains("not supported"),
        "rejection must name the failure: {stderr}"
    );
}

#[test]
fn build_output_defaults_to_ifcx_extension() {
    // The cli default is <input>.ifcx (master parity) — run on a copy in the
    // target tmpdir so the copied corpus is never rewritten.
    let input = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("../samples/bimr/wall.bimr");
    let copy = tmp("wall_copy.bimr");
    fs::copy(&input, &copy).expect("copy");
    let out = Command::new(env!("CARGO_BIN_EXE_bimr-cli"))
        .args(["build", copy.to_str().expect("utf8")])
        .output()
        .expect("spawn");
    assert!(out.status.success());
    let default_out = copy.with_extension("ifcx");
    assert_eq!(
        fs::read_to_string(&default_out).expect("read"),
        EXPECTED_IFCX
    );
}