//! ct.1: E2E coverage for the CLI surface of the canonical-type-names
//! validator. The unit tests in `workspace.rs` already prove the
//! validator fires; these tests prove the diagnostic survives the
//! `WorkspaceLoadError -> Diagnostic` translation in
//! `crates/ail/src/main.rs::workspace_error_to_diagnostic` AND is
//! observable on the CLI in both `--json` and human modes (exit code
//! + diagnostic code in the output stream).
//!
//! Companion to the happy-path test below: post-migration
//! `examples/ordering_match.ail.json` must `ail check` cleanly. If
//! someone reverts the migration (or breaks the canonical-form
//! acceptance path in the registry), that test goes red.

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

fn ail_bin() -> PathBuf {
    // CARGO_BIN_EXE_<name> is set by cargo when building integration tests.
    PathBuf::from(env!("CARGO_BIN_EXE_ail"))
}

fn examples_dir() -> PathBuf {
    // CARGO_MANIFEST_DIR points at `crates/ail`; examples/ sits at the
    // workspace root, two levels up.
    PathBuf::from(env!("CARGO_MANIFEST_DIR"))
        .join("..")
        .join("..")
        .join("examples")
}

/// Property: a workspace whose entry module contains a bare
/// cross-module Type::Con / Term::Ctor reference — here `Ordering`,
/// satisfiable only via the auto-injected `prelude` — is rejected by
/// `ail check --json` with diagnostic code `bare-cross-module-type-ref`
/// and non-zero exit. Guards against `workspace_error_to_diagnostic`
/// losing the `BareCrossModuleTypeRef` arm or the validator no longer
/// firing through the CLI loader path.
#[test]
fn check_json_emits_bare_cross_module_type_ref() {
    let fixture = examples_dir().join("test_ct1_bare_xmod_rejected.ail.json");
    let output = Command::new(ail_bin())
        .args(["check", "--json", fixture.to_str().unwrap()])
        .output()
        .expect("ail binary must launch");
    assert!(
        !output.status.success(),
        "ail check must fail on bare cross-module ref; stdout={} stderr={}",
        String::from_utf8_lossy(&output.stdout),
        String::from_utf8_lossy(&output.stderr),
    );
    let stdout = String::from_utf8(output.stdout).expect("stdout is utf-8");
    let diags: serde_json::Value =
        serde_json::from_str(&stdout).expect("--json mode emits a JSON array on stdout");
    let arr = diags.as_array().expect("diagnostics is a JSON array");
    assert!(
        arr.iter().any(|d| d["code"] == "bare-cross-module-type-ref"),
        "expected `bare-cross-module-type-ref` in diagnostics array; got {stdout}"
    );
}

/// Property: a qualified `<owner>.<name>` Type::Con where `<owner>` is
/// not a known module is rejected by `ail check --json` with
/// diagnostic code `bad-cross-module-type-ref` and non-zero exit.
/// Guards against `workspace_error_to_diagnostic` losing the
/// `BadCrossModuleTypeRef` arm.
#[test]
fn check_json_emits_bad_cross_module_type_ref() {
    let fixture = examples_dir().join("test_ct1_bad_qualifier.ail.json");
    let output = Command::new(ail_bin())
        .args(["check", "--json", fixture.to_str().unwrap()])
        .output()
        .expect("ail binary must launch");
    assert!(
        !output.status.success(),
        "ail check must fail on unknown qualifier; stdout={} stderr={}",
        String::from_utf8_lossy(&output.stdout),
        String::from_utf8_lossy(&output.stderr),
    );
    let stdout = String::from_utf8(output.stdout).expect("stdout is utf-8");
    let diags: serde_json::Value =
        serde_json::from_str(&stdout).expect("--json mode emits a JSON array on stdout");
    let arr = diags.as_array().expect("diagnostics is a JSON array");
    assert!(
        arr.iter().any(|d| d["code"] == "bad-cross-module-type-ref"),
        "expected `bad-cross-module-type-ref` in diagnostics array; got {stdout}"
    );
}

/// Property: a qualified class name in an `InstanceDef.class` field
/// (here `prelude.Eq`) is rejected by `ail check --json` with
/// diagnostic code `qualified-class-name` and non-zero exit. ct.1
/// reserves module qualification for type names; classes stay bare in
/// this milestone. Guards against `workspace_error_to_diagnostic`
/// losing the `QualifiedClassName` arm.
#[test]
fn check_json_emits_qualified_class_name() {
    let fixture = examples_dir().join("test_ct1_qualified_class_rejected.ail.json");
    let output = Command::new(ail_bin())
        .args(["check", "--json", fixture.to_str().unwrap()])
        .output()
        .expect("ail binary must launch");
    assert!(
        !output.status.success(),
        "ail check must fail on qualified class name; stdout={} stderr={}",
        String::from_utf8_lossy(&output.stdout),
        String::from_utf8_lossy(&output.stderr),
    );
    let stdout = String::from_utf8(output.stdout).expect("stdout is utf-8");
    let diags: serde_json::Value =
        serde_json::from_str(&stdout).expect("--json mode emits a JSON array on stdout");
    let arr = diags.as_array().expect("diagnostics is a JSON array");
    assert!(
        arr.iter().any(|d| d["code"] == "qualified-class-name"),
        "expected `qualified-class-name` in diagnostics array; got {stdout}"
    );
}

/// Property: in non-JSON (human) mode `ail check` exits non-zero on a
/// ct.1 validator failure and writes an actionable error message to
/// stderr — naming both the offending type and the migration command
/// the author should run. Pinning the human-mode path separately
/// because in this mode the loader error short-circuits via `anyhow`
/// (no diagnostic-code prefix) and is formatted by the
/// `WorkspaceLoadError`'s `thiserror` Display impl rather than by
/// `workspace_error_to_diagnostic`. A regression that left `--json`
/// working but stripped the actionable hint from the human path
/// would otherwise ship unnoticed. The bare-cross-module fixture is
/// the representative case; the property — actionable hint in the
/// Display impl — is named per-variant.
#[test]
fn check_human_mode_emits_actionable_message_to_stderr() {
    let fixture = examples_dir().join("test_ct1_bare_xmod_rejected.ail.json");
    let output = Command::new(ail_bin())
        .args(["check", fixture.to_str().unwrap()])
        .output()
        .expect("ail binary must launch");
    assert!(
        !output.status.success(),
        "ail check (human mode) must fail on bare cross-module ref"
    );
    let stderr = String::from_utf8(output.stderr).expect("stderr is utf-8");
    assert!(
        stderr.contains("Ordering"),
        "expected the offending type name in stderr; got {stderr}"
    );
    assert!(
        stderr.contains("ail migrate-canonical-types"),
        "expected the migration-command hint in stderr; got {stderr}"
    );
}

/// Property: the post-migration `examples/ordering_match.ail.json`
/// (Term::Ctor `Ordering` -> `prelude.Ordering`) typechecks cleanly
/// through the CLI — `ail check` exits 0 with no diagnostics.
/// Guards against (a) a revert of the ct.1.5 migration, (b) a
/// regression in `Registry::normalize_type_for_lookup` that would make
/// the canonical (qualified) form fail to dispatch where the bare
/// form used to succeed.
#[test]
fn check_ordering_match_post_migration_is_clean() {
    let fixture = examples_dir().join("ordering_match.ail.json");
    let output = Command::new(ail_bin())
        .args(["check", "--json", fixture.to_str().unwrap()])
        .output()
        .expect("ail binary must launch");
    assert!(
        output.status.success(),
        "ail check must succeed on migrated ordering_match; stdout={} stderr={}",
        String::from_utf8_lossy(&output.stdout),
        String::from_utf8_lossy(&output.stderr),
    );
    let stdout = String::from_utf8(output.stdout).expect("stdout is utf-8");
    let diags: serde_json::Value =
        serde_json::from_str(&stdout).expect("--json mode emits a JSON array on stdout");
    let arr = diags.as_array().expect("diagnostics is a JSON array");
    assert!(
        arr.is_empty(),
        "expected zero diagnostics on migrated fixture; got {stdout}"
    );
}