//! Integration tests for the `cph-check` orchestrator.
//!
//! These exercise phase gating and the public API against the shared `mini`
//! fixture (`crates/cph-typst/tests/fixtures/mini/`) and small throwaway
//! fixtures built in a temp dir. The typst Engine is pointed at the repo's real
//! `render/` package via `Engine::with_render_dir`.

use std::path::PathBuf;

use cph_diag::DiagCode;
use cph_typst::Engine;

/// `<this crate>/../cph-typst/tests/fixtures/mini` — the known-good lesson.
fn mini_fixture() -> PathBuf {
    PathBuf::from(env!("CARGO_MANIFEST_DIR"))
        .join("..")
        .join("cph-typst")
        .join("tests")
        .join("fixtures")
        .join("mini")
}

/// `<this crate>/../../render` — the repo render package.
fn render_dir() -> PathBuf {
    PathBuf::from(env!("CARGO_MANIFEST_DIR"))
        .join("..")
        .join("..")
        .join("render")
}

fn engine() -> Engine {
    Engine::with_render_dir(render_dir())
}

#[test]
fn good_fixture_has_no_errors() {
    let report = cph_check::check(&mini_fixture(), &engine());
    assert!(report.lesson_loaded, "mini fixture should load");
    assert_eq!(
        report.error_count(),
        0,
        "mini fixture should have zero errors, got: {:#?}",
        report.diagnostics
    );
    assert!(!report.has_errors());
}

#[test]
fn unknown_kind_is_an_error() {
    // Build a throwaway lesson whose part declares kind "frob".
    let tmp = tempdir();
    std::fs::write(
        tmp.join("manifest.toml"),
        r#"
[project]
id = "broken"
name = "broken"

[info]
title = "broken"

[[parts]]
kind = "frob"
path = "elements/widget"
"#,
    )
    .unwrap();
    let part_dir = tmp.join("elements").join("widget");
    std::fs::create_dir_all(&part_dir).unwrap();
    std::fs::write(part_dir.join("element.toml"), "kind = \"frob\"\n").unwrap();

    let report = cph_check::check(&tmp, &engine());
    assert!(report.lesson_loaded);
    assert!(report.has_errors());
    assert!(
        report
            .diagnostics
            .iter()
            .any(|d| d.code == DiagCode::UnknownKind && d.message.contains("frob")),
        "expected an UnknownKind error mentioning 'frob', got: {:#?}",
        report.diagnostics
    );
    cleanup(&tmp);
}

#[test]
fn hard_manifest_failure_sets_lesson_not_loaded() {
    let tmp = tempdir();
    // No manifest.toml at all → cph_model::load returns None.
    let report = cph_check::check(&tmp, &engine());
    assert!(!report.lesson_loaded, "missing manifest is a hard failure");
    assert!(report.has_errors());
    cleanup(&tmp);
}

#[test]
fn build_returns_pdf_on_good_fixture() {
    let (pdf, report) = cph_check::build(&mini_fixture(), &engine(), "student");
    assert!(report.lesson_loaded);
    assert_eq!(
        report.error_count(),
        0,
        "no check errors expected, got: {:#?}",
        report.diagnostics
    );
    let pdf = pdf.expect("expected PDF bytes for the good fixture");
    assert!(pdf.starts_with(b"%PDF"), "output should be a PDF");
    assert!(pdf.len() > 1000, "PDF should be non-trivial");
}

#[test]
fn build_returns_none_on_broken_fixture() {
    // A part folder is missing → cph-model flags PartPathMissing (an error),
    // so build refuses before ever compiling.
    let tmp = tempdir();
    std::fs::write(
        tmp.join("manifest.toml"),
        r#"
[project]
id = "broken"
name = "broken"

[info]
title = "broken"

[[parts]]
kind = "segment"
path = "segments/does-not-exist"
"#,
    )
    .unwrap();

    let (pdf, report) = cph_check::build(&tmp, &engine(), "student");
    assert!(pdf.is_none(), "broken lesson must not produce a PDF");
    assert!(report.has_errors());
    cleanup(&tmp);
}

/// Write a throwaway one-segment lesson into `tmp`, with the given `[targets.x]`
/// body spliced in. Returns nothing; the caller runs `check`.
fn write_segment_lesson_with_target(tmp: &PathBuf, target_body: &str) {
    std::fs::write(
        tmp.join("manifest.toml"),
        format!(
            r#"
[project]
id = "cov"
name = "cov"

[info]
title = "cov"

[[parts]]
kind = "segment"
path = "segments/intro"

{target_body}
"#
        ),
    )
    .unwrap();
    let part_dir = tmp.join("segments").join("intro");
    std::fs::create_dir_all(&part_dir).unwrap();
    std::fs::write(part_dir.join("element.toml"), "kind = \"segment\"\n").unwrap();
    std::fs::write(part_dir.join("textbook.typ"), "Hello.\n").unwrap();
}

#[test]
fn covers_omitting_used_kind_warns_render_ignored() {
    // A target that declares `covers = ["example"]` does NOT cover the lesson's
    // `segment` part → exactly one RenderIgnored warning (non-blocking).
    let tmp = tempdir();
    write_segment_lesson_with_target(
        &tmp,
        r#"[targets.handout]
artifact = { type = "single-file", filepath = "build/handout.pdf" }
covers = ["example"]
[[targets.handout.steps]]
type = "typst-compile"
template = "exports/handout.typ"
"#,
    );

    let report = cph_check::check(&tmp, &engine());
    assert!(report.lesson_loaded);
    let render_ignored: Vec<_> = report
        .diagnostics
        .iter()
        .filter(|d| d.code == DiagCode::RenderIgnored)
        .collect();
    assert_eq!(
        render_ignored.len(),
        1,
        "expected exactly one RenderIgnored warning, got: {:#?}",
        report.diagnostics
    );
    // It is a non-blocking warning, so legality is unaffected by it.
    assert_eq!(
        report.warning_count(),
        1,
        "the coverage gap is a warning: {:#?}",
        report.diagnostics
    );
    cleanup(&tmp);
}

#[test]
fn covers_including_used_kind_has_no_render_ignored() {
    // A target that covers `segment` (the only used kind) → no RenderIgnored.
    let tmp = tempdir();
    write_segment_lesson_with_target(
        &tmp,
        r#"[targets.handout]
artifact = { type = "single-file", filepath = "build/handout.pdf" }
covers = ["segment"]
[[targets.handout.steps]]
type = "typst-compile"
template = "exports/handout.typ"
"#,
    );

    let report = cph_check::check(&tmp, &engine());
    assert!(report.lesson_loaded);
    assert!(
        !report
            .diagnostics
            .iter()
            .any(|d| d.code == DiagCode::RenderIgnored),
        "a covering target should yield no RenderIgnored, got: {:#?}",
        report.diagnostics
    );
    cleanup(&tmp);
}

#[test]
fn absent_covers_defaults_to_full_coverage() {
    // No `covers` key at all → the orchestrator defaults to all known kinds, so
    // even a non-"student"/"teacher" target name covers `segment`. (This is the
    // behavior change: coverage now follows the declaration/default, not a
    // hardcoded target-name allowlist.)
    let tmp = tempdir();
    write_segment_lesson_with_target(
        &tmp,
        r#"[targets.handout]
artifact = { type = "single-file", filepath = "build/handout.pdf" }
[[targets.handout.steps]]
type = "typst-compile"
template = "exports/handout.typ"
"#,
    );

    let report = cph_check::check(&tmp, &engine());
    assert!(report.lesson_loaded);
    assert!(
        !report
            .diagnostics
            .iter()
            .any(|d| d.code == DiagCode::RenderIgnored),
        "an absent `covers` defaults to full coverage, got: {:#?}",
        report.diagnostics
    );
    cleanup(&tmp);
}

// --- tiny temp-dir helpers (no external dev-dep) ------------------------------

fn tempdir() -> PathBuf {
    let mut p = std::env::temp_dir();
    let nanos = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)
        .unwrap()
        .as_nanos();
    p.push(format!(
        "cph-check-test-{nanos}-{:?}",
        std::thread::current().id()
    ));
    std::fs::create_dir_all(&p).unwrap();
    p
}

fn cleanup(p: &PathBuf) {
    let _ = std::fs::remove_dir_all(p);
}