//! 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::{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: &Path, 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);
}

/// Write a one-segment lesson with a `file-tree` shell target whose `run` is the
/// given command. Returns nothing; the caller runs `run_shell_target`.
fn write_shell_target_lesson(tmp: &Path, run: &str) {
    std::fs::write(
        tmp.join("manifest.toml"),
        format!(
            r#"
[project]
id = "sh"
name = "sh"

[info]
title = "sh"

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

[targets.assets]
artifact = {{ type = "file-tree", root = "build/assets", outputs = "**/*" }}
[[targets.assets.steps]]
type = "shell"
run = "{run}"
"#
        ),
    )
    .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"), "Hi.\n").unwrap();
}

#[test]
fn target_is_shell_detects_shape() {
    let tmp = tempdir();
    write_shell_target_lesson(&tmp, "true");
    assert!(cph_check::target_is_shell(&tmp, "assets"));
    assert!(!cph_check::target_is_shell(&tmp, "nonexistent"));
    cleanup(&tmp);
}

#[test]
fn run_shell_target_executes_in_engineering_root() {
    // The command writes a file under the engineering root; cwd must be the root.
    let tmp = tempdir();
    write_shell_target_lesson(
        &tmp,
        "mkdir -p build/assets && printf ok > build/assets/marker.txt",
    );

    let report = cph_check::run_shell_target(&tmp, &engine(), "assets");
    assert!(report.ok, "shell target should succeed: {:#?}", report);
    assert_eq!(report.outcomes.len(), 1);
    assert!(report.outcomes[0].ok());

    // The side effect landed in the engineering root.
    let marker = tmp.join("build").join("assets").join("marker.txt");
    assert_eq!(std::fs::read_to_string(&marker).unwrap(), "ok");
    cleanup(&tmp);
}

#[test]
fn run_shell_target_reports_nonzero_exit() {
    let tmp = tempdir();
    write_shell_target_lesson(&tmp, "exit 3");

    let report = cph_check::run_shell_target(&tmp, &engine(), "assets");
    assert!(!report.ok, "non-zero exit must fail the run");
    assert_eq!(report.outcomes.len(), 1);
    assert_eq!(report.outcomes[0].status, Some(3));
    cleanup(&tmp);
}

#[test]
fn run_shell_target_refuses_broken_lesson() {
    // A part path that doesn't exist → check error → shell steps never run.
    let tmp = tempdir();
    std::fs::write(
        tmp.join("manifest.toml"),
        r#"
[project]
id = "sh"
name = "sh"

[info]
title = "sh"

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

[targets.assets]
artifact = { type = "file-tree", root = "build/assets", outputs = "**/*" }
[[targets.assets.steps]]
type = "shell"
run = "printf SHOULD_NOT_RUN > build/ran.txt"
"#,
    )
    .unwrap();

    let report = cph_check::run_shell_target(&tmp, &engine(), "assets");
    assert!(!report.ok);
    assert!(
        report.outcomes.is_empty(),
        "no command should run on a broken lesson"
    );
    assert!(report.check.has_errors());
    assert!(
        !tmp.join("build").join("ran.txt").exists(),
        "the command must not have executed"
    );
    cleanup(&tmp);
}

// --- assemble-markdown target (ADR-0015) ---------------------------------------

/// Write a two-segment lesson where each segment carries a `slides.md` markdown
/// content file, plus a `slides` target that assembles them. The `which` slice
/// controls which segments get a `slides.md` (so the "skip absent" path can be
/// exercised). Returns nothing; the caller runs `run_markdown_assemble_target`.
fn write_markdown_assemble_target_lesson(tmp: &Path, slides: &[(&str, &str)]) {
    let mut parts = String::new();
    for (i, (name, _)) in slides.iter().enumerate() {
        if i > 0 {
            parts.push('\n');
        }
        parts.push_str(&format!(
            "[[parts]]\nkind = \"segment\"\npath = \"segments/{name}\"\n"
        ));
    }
    std::fs::write(
        tmp.join("manifest.toml"),
        format!(
            r#"
[project]
id = "md"
name = "md"

[info]
title = "md"

{parts}

[targets.slides]
artifact = {{ type = "single-file", filepath = "build/slides.md" }}
[[targets.slides.steps]]
type = "assemble-markdown"
field = "slides"
"#
        ),
    )
    .unwrap();
    for (name, body) in slides {
        let dir = tmp.join("segments").join(name);
        std::fs::create_dir_all(&dir).unwrap();
        std::fs::write(dir.join("element.toml"), "kind = \"segment\"\n").unwrap();
        std::fs::write(dir.join("textbook.typ"), "text.\n").unwrap();
        std::fs::write(dir.join("slides.md"), body).unwrap();
    }
}

#[test]
fn target_is_markdown_assemble_detects_shape() {
    let tmp = tempdir();
    write_markdown_assemble_target_lesson(&tmp, &[("a", "# A"), ("b", "# B")]);
    assert!(cph_check::target_is_markdown_assemble(&tmp, "slides"));
    // The student target doesn't exist here → falls through to typst path → false.
    assert!(!cph_check::target_is_markdown_assemble(&tmp, "student"));
    cleanup(&tmp);
}

#[test]
fn run_markdown_assemble_target_concatenates_in_parts_order() {
    let tmp = tempdir();
    write_markdown_assemble_target_lesson(
        &tmp,
        &[
            ("intro", "# 规则一\n- 范围"),
            ("rule2", "# 规则二\n$8\\times$"),
        ],
    );

    let report = cph_check::run_markdown_assemble_target(&tmp, &engine(), "slides");
    assert!(report.ok, "assembly should succeed: {:#?}", report);
    assert_eq!(report.outcomes.len(), 1);
    let o = &report.outcomes[0];
    assert!(o.ok());
    assert_eq!(o.parts_read, 2);
    assert_eq!(o.field, "slides");

    let out = tmp.join("build").join("slides.md");
    let body = std::fs::read_to_string(&out).unwrap();
    // Both parts present, in declared order, joined by a blank line.
    let intro_idx = body.find("规则一").unwrap();
    let rule2_idx = body.find("规则二").unwrap();
    assert!(intro_idx < rule2_idx, "parts must keep manifest order");
    assert!(body.contains("$8\\times$"), "KaTeX source survives as text");
    cleanup(&tmp);
}

#[test]
fn run_markdown_assemble_target_skips_parts_without_the_field() {
    // Only the first segment has a slides.md; the second is skipped (optional).
    let tmp = tempdir();
    let mut parts = String::new();
    parts.push_str("[[parts]]\nkind = \"segment\"\npath = \"segments/a\"\n\n");
    parts.push_str("[[parts]]\nkind = \"segment\"\npath = \"segments/b\"\n");
    std::fs::write(
        tmp.join("manifest.toml"),
        format!(
            r#"
[project]
id = "md"
name = "md"

[info]
title = "md"

{parts}

[targets.slides]
artifact = {{ type = "single-file", filepath = "build/slides.md" }}
[[targets.slides.steps]]
type = "assemble-markdown"
field = "slides"
"#
        ),
    )
    .unwrap();
    for name in ["a", "b"] {
        let dir = tmp.join("segments").join(name);
        std::fs::create_dir_all(&dir).unwrap();
        std::fs::write(dir.join("element.toml"), "kind = \"segment\"\n").unwrap();
        std::fs::write(dir.join("textbook.typ"), "text.\n").unwrap();
    }
    // Only `a` gets a slides.md.
    std::fs::write(tmp.join("segments/a/slides.md"), "# A only\n").unwrap();

    let report = cph_check::run_markdown_assemble_target(&tmp, &engine(), "slides");
    assert!(report.ok, "{:#?}", report);
    assert_eq!(report.outcomes[0].parts_read, 1);
    let body = std::fs::read_to_string(tmp.join("build/slides.md")).unwrap();
    // The assembler prepends the course title (info.title = "md") as an h1,
    // then the single part's slides.md.
    assert_eq!(body, "# md\n\n# A only\n");
    cleanup(&tmp);
}

#[test]
fn run_markdown_assemble_target_copies_referenced_images() {
    // A slides.md that references two local images; both must be copied from
    // the engineering root into the build root (same relative path) so the
    // build dir is self-contained (ADR-0015).
    let tmp = tempdir();
    std::fs::write(
        tmp.join("manifest.toml"),
        r#"
[project]
id = "md"
name = "md"

[info]
title = "md"

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

[targets.slides]
artifact = { type = "single-file", filepath = "build/slides.md" }
[[targets.slides.steps]]
type = "assemble-markdown"
field = "slides"
"#,
    )
    .unwrap();
    let dir = tmp.join("segments").join("a");
    std::fs::create_dir_all(&dir).unwrap();
    std::fs::write(dir.join("element.toml"), "kind = \"segment\"\n").unwrap();
    std::fs::write(dir.join("textbook.typ"), "text.\n").unwrap();
    std::fs::write(
        dir.join("slides.md"),
        "## A\n\n![one](assets/img/one.png)\n\n![two](assets/img/two.png)\n",
    )
    .unwrap();
    // The two referenced images exist at the engineering root.
    std::fs::create_dir_all(tmp.join("assets/img")).unwrap();
    std::fs::write(tmp.join("assets/img/one.png"), b"PNG1").unwrap();
    std::fs::write(tmp.join("assets/img/two.png"), b"PNG2").unwrap();

    let report = cph_check::run_markdown_assemble_target(&tmp, &engine(), "slides");
    assert!(report.ok, "{:#?}", report);

    // Both images copied into the build root, preserving the assets/img/ path.
    assert_eq!(
        std::fs::read(tmp.join("build/assets/img/one.png")).unwrap(),
        b"PNG1"
    );
    assert_eq!(
        std::fs::read(tmp.join("build/assets/img/two.png")).unwrap(),
        b"PNG2"
    );
    cleanup(&tmp);
}

#[test]
fn run_markdown_assemble_target_fails_on_missing_referenced_image() {
    // A slides.md references an image that does NOT exist at the engineering
    // root → a build-process error (self-contained build would be broken),
    // not a lesson diagnostic.
    let tmp = tempdir();
    std::fs::write(
        tmp.join("manifest.toml"),
        r#"
[project]
id = "md"
name = "md"

[info]
title = "md"

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

[targets.slides]
artifact = { type = "single-file", filepath = "build/slides.md" }
[[targets.slides.steps]]
type = "assemble-markdown"
field = "slides"
"#,
    )
    .unwrap();
    let dir = tmp.join("segments").join("a");
    std::fs::create_dir_all(&dir).unwrap();
    std::fs::write(dir.join("element.toml"), "kind = \"segment\"\n").unwrap();
    std::fs::write(dir.join("textbook.typ"), "text.\n").unwrap();
    std::fs::write(
        dir.join("slides.md"),
        "## A\n\n![ghost](assets/img/ghost.png)\n",
    )
    .unwrap();
    // No image created → reference is dangling.

    let report = cph_check::run_markdown_assemble_target(&tmp, &engine(), "slides");
    assert!(!report.ok, "a missing referenced image must fail the build");
    let o = &report.outcomes[0];
    assert!(o.error.as_deref().unwrap_or("").contains("ghost.png"));
    // The markdown was still written, but the image was not (it doesn't exist).
    assert!(tmp.join("build/slides.md").is_file());
    cleanup(&tmp);
}

#[test]
fn run_markdown_assemble_target_refuses_broken_lesson() {
    // A part path that doesn't exist → check error → assembly never runs.
    let tmp = tempdir();
    std::fs::write(
        tmp.join("manifest.toml"),
        r#"
[project]
id = "md"
name = "md"

[info]
title = "md"

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

[targets.slides]
artifact = { type = "single-file", filepath = "build/slides.md" }
[[targets.slides.steps]]
type = "assemble-markdown"
field = "slides"
"#,
    )
    .unwrap();

    let report = cph_check::run_markdown_assemble_target(&tmp, &engine(), "slides");
    assert!(!report.ok);
    assert!(report.outcomes.is_empty(), "no assembly on a broken lesson");
    assert!(report.check.has_errors());
    assert!(
        !tmp.join("build").join("slides.md").exists(),
        "nothing should have been written"
    );
    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: &Path) {
    let _ = std::fs::remove_dir_all(p);
}