jsslint-core 1.0.1

//! Code-style rules — mirrors `journals/jss/rules/code_style.py`
//! (JSS-CODE-001/002/003).

use super::tex_common::tex_violation_with_fix;
use crate::report::{Fix, FixConfidence, Violation};
use crate::tex::extract;
use crate::tex::node::{GroupNode, MacroNode, Node};
use crate::tex::prose::{walk, Slot, CODE_INPUT_ENVS};
use crate::tex::{position::LineIndex, ParsedTex};
use regex::Regex;
use std::sync::LazyLock;

static COMMENT_LINE_RE: LazyLock<Regex> = LazyLock::new(|| {
    // Python's `(?m)#+[^\S\n]+\S[^\n]*` — Rust: match per-line via
    // `(?m)` multi-line mode (`regex` crate supports it); `[^\S\n]`
    // (whitespace-but-not-newline) has no single-char Rust class, so
    // spell it as `[ \t\r\x0c\x0b]` (ASCII horizontal/vertical
    // whitespace minus `\n`, matching Python's `\s` minus `\n` for the
    // ASCII case this corpus uses).
    Regex::new(r"(?m)#+[ \t\r\x0c\x0b]+\S[^\n]*").unwrap()
});

static LIBRARY_UNQUOTED_RE: LazyLock<Regex> = LazyLock::new(|| {
    Regex::new(r"\b(?:library|data|require|requireNamespace)\(\s*([A-Za-z][A-Za-z0-9_.]*)\s*[,)]")
        .unwrap()
});

static MISSING_SPACES_RE: LazyLock<Regex> = LazyLock::new(|| {
    Regex::new(
        r"(?:[A-Za-z0-9_.)\]](?:<<-|<-|->|==|!=|<=|>=)[A-Za-z0-9_.(\[])|(?:[A-Za-z0-9_.)\]][=+\-*/][A-Za-z0-9_.(\[])|(?:,[A-Za-z0-9_.(\[])",
    )
    .unwrap()
});

static CODE_ENV_MISSING_COMMA_SPACE_RE: LazyLock<Regex> =
    LazyLock::new(|| Regex::new(r#",[A-Za-z0-9_.(\["']"#).unwrap());
static CODE_ENV_COMMENT_RE: LazyLock<Regex> = LazyLock::new(|| Regex::new(r"#[^\n]*").unwrap());
static CODE_ENV_STRING_RE: LazyLock<Regex> =
    LazyLock::new(|| Regex::new(r#""[^"\n]*"|'[^'\n]*'"#).unwrap());
static CLEAN_R_IDENT_RE: LazyLock<Regex> =
    LazyLock::new(|| Regex::new(r"^[A-Za-z][A-Za-z0-9._]*$").unwrap());
static IDENTIFIER_ONLY_RE: LazyLock<Regex> =
    LazyLock::new(|| Regex::new(r"^[A-Za-z][A-Za-z0-9_.\-]*$").unwrap());
static VERSION_OR_LABEL_RE: LazyLock<Regex> = LazyLock::new(|| {
    Regex::new(r"^(?:[0-9][\w.\-]*|[A-Za-z][\w.\-]*\s*\\?%[\w.\-\s\\]*)$").unwrap()
});
// Note: Python's `code_style.py` also defines `_KEYWORD_ARG_RE` at this
// point in the module but never references it anywhere else — dead
// code in the source being ported, not an oversight here. Omitted.
static PATH_LIKE_RE: LazyLock<Regex> =
    LazyLock::new(|| Regex::new(r"^[A-Za-z0-9_.\-]+(?:/[A-Za-z0-9_.\-]*)+/?$").unwrap());
// `\code{--fix}`, `\code{--fix --dry-run}`, `\code{.jss-lint.toml}`,
// `\code{cargo install jsslint-cli}` — command-line flags, dotfile
// names, and space-separated command words. A leading dash is option
// syntax and internal hyphens are part of the name, not subtraction;
// applied per whitespace-separated token so a real expression anywhere
// in the sample still trips the operator check.
static NAME_LIKE_TOKEN_RE: LazyLock<Regex> = LazyLock::new(|| {
    Regex::new(r"^(?:--?|\.)?[A-Za-z][A-Za-z0-9_.\-]*$|^[A-Za-z0-9_.\-]+(?:/[A-Za-z0-9_.\-]*)+/?$")
        .unwrap()
});
static SCIENTIFIC_NOTATION_RE: LazyLock<Regex> =
    LazyLock::new(|| Regex::new(r"\b\d+(?:\.\d+)?[eE][-+]?\d+\b").unwrap());
static STRING_LITERAL_RE: LazyLock<Regex> =
    LazyLock::new(|| Regex::new(r#""[^"\n]*"|'[^'\n]*'"#).unwrap());

const SINGLE_CHAR_ESCAPE_MACROS: &[&str] = &["%", "&", "_", "#", "$", "{", "}", "\\"];

/// JSS-CODE-001 — code-display envs contain no `#`-style comments.
pub fn check_code_001(file: &str, parsed: &ParsedTex) -> Vec<Violation> {
    let line_index = LineIndex::new(&parsed.chars);
    let mut out = Vec::new();
    walk(&parsed.nodes, &mut |node, _ancestors| {
        let Node::Environment(env) = node else { return };
        if !CODE_INPUT_ENVS.contains(&env.environmentname.as_str()) {
            return;
        }
        for child in &env.nodelist {
            let Node::Chars(c) = child else { continue };
            let Some(m) = COMMENT_LINE_RE.find(&c.chars) else {
                continue;
            };
            let abs_pos = c.span.pos + c.chars[..m.start()].chars().count();
            out.push(tex_violation_with_fix(
                file,
                &line_index,
                abs_pos,
                "JSS-CODE-001",
                Some("Move the comment into the surrounding LaTeX text.".to_string()),
                None,
            ));
            break; // one violation per code block is enough
        }
    });
    out
}

/// JSS-CODE-002 — `library()`/`data()`/`require()`/`requireNamespace()`
/// quote their first argument.
pub fn check_code_002(file: &str, parsed: &ParsedTex) -> Vec<Violation> {
    let line_index = LineIndex::new(&parsed.chars);
    let mut out = Vec::new();
    walk(&parsed.nodes, &mut |node, _ancestors| {
        let Node::Environment(env) = node else { return };
        if !CODE_INPUT_ENVS.contains(&env.environmentname.as_str()) {
            return;
        }
        for child in &env.nodelist {
            let Node::Chars(c) = child else { continue };
            for m in LIBRARY_UNQUOTED_RE.captures_iter(&c.chars) {
                let whole = m.get(0).unwrap();
                let arg = m.get(1).unwrap();
                let abs_pos = c.span.pos + c.chars[..whole.start()].chars().count();
                let bareword = arg.as_str();
                // Python's `.replace()` (no count) replaces every
                // occurrence, not just the first — match that exactly
                // rather than assume `bareword` appears once.
                let quoted = whole.as_str().replace(bareword, &format!("\"{bareword}\""));
                let suggestion = format!("Quote the argument: e.g., {}.", super::py_repr(&quoted));
                let fix = if CLEAN_R_IDENT_RE.is_match(bareword) {
                    let bareword_start = c.span.pos + c.chars[..arg.start()].chars().count();
                    let bareword_end = c.span.pos + c.chars[..arg.end()].chars().count();
                    Some(Fix {
                        start: bareword_start,
                        end: bareword_end,
                        replacement: format!("\"{bareword}\""),
                        description: "quote first argument to library() / data()".to_string(),
                        confidence: FixConfidence::Safe,
                    })
                } else {
                    None
                };
                out.push(tex_violation_with_fix(
                    file,
                    &line_index,
                    abs_pos,
                    "JSS-CODE-002",
                    Some(suggestion),
                    fix,
                ));
            }
        }
    });
    out
}

/// JSS-CODE-003 — code samples use spaces around operators and after
/// commas, checked both inside code-display envs and `\code{...}`.
pub fn check_code_003(file: &str, parsed: &ParsedTex) -> Vec<Violation> {
    let line_index = LineIndex::new(&parsed.chars);
    let mut out = Vec::new();

    walk(&parsed.nodes, &mut |node, _ancestors| {
        let Node::Environment(env) = node else { return };
        if !CODE_INPUT_ENVS.contains(&env.environmentname.as_str()) {
            return;
        }
        if let Some(v) = scan_code_env_for_spacing(file, &line_index, env) {
            out.push(v);
        }
    });

    extract::iter_with_parent_visit(&parsed.nodes, &mut |parent: &[Slot], idx, node| {
        let Node::Macro(m) = node else { return };
        if m.macroname != "code" {
            return;
        }
        let Some(group) = first_group_arg(m, parent, idx) else {
            return;
        };
        let text = group_plain_text(group);
        if text.is_empty() {
            return;
        }
        let stripped = text.trim();
        if IDENTIFIER_ONLY_RE.is_match(stripped)
            || VERSION_OR_LABEL_RE.is_match(stripped)
            || PATH_LIKE_RE.is_match(stripped)
        {
            return;
        }
        // Command line made of flag / name / path tokens only.
        if !stripped.is_empty()
            && stripped
                .split_whitespace()
                .all(|t| NAME_LIKE_TOKEN_RE.is_match(t))
        {
            return;
        }
        let cleaned = SCIENTIFIC_NOTATION_RE.replace_all(&text, "");
        let cleaned = STRING_LITERAL_RE.replace_all(&cleaned, "S");
        if MISSING_SPACES_RE.is_match(&cleaned) {
            out.push(tex_violation_with_fix(
                file,
                &line_index,
                m.span.pos,
                "JSS-CODE-003",
                Some("Add spaces around operators and after commas in the code sample (e.g., 'y = a + b * x').".to_string()),
                None,
            ));
        }
    });

    out
}

fn scan_code_env_for_spacing(
    file: &str,
    line_index: &LineIndex,
    env: &crate::tex::node::EnvironmentNode,
) -> Option<Violation> {
    for child in &env.nodelist {
        let Node::Chars(c) = child else { continue };
        let cleaned = CODE_ENV_COMMENT_RE.replace_all(&c.chars, "");
        let cleaned = SCIENTIFIC_NOTATION_RE.replace_all(&cleaned, "");
        let cleaned = CODE_ENV_STRING_RE.replace_all(&cleaned, "S");
        if CODE_ENV_MISSING_COMMA_SPACE_RE.is_match(&cleaned)
            || MISSING_SPACES_RE.is_match(&cleaned)
        {
            return Some(tex_violation_with_fix(
                file,
                line_index,
                env.span.pos,
                "JSS-CODE-003",
                Some(
                    "Add spaces around operators and after commas in the code sample (e.g., 'f(x = 1, y = 2)' rather than 'f(x=1,y=2)')."
                        .to_string(),
                ),
                None,
            ));
        }
    }
    None
}

fn first_group_arg<'a>(
    macro_node: &'a MacroNode,
    parent: &[Slot<'a>],
    idx: usize,
) -> Option<&'a GroupNode> {
    for arg in &macro_node.args {
        if let Some(Node::Group(g)) = arg {
            return Some(g);
        }
    }
    extract::next_group_arg(parent, idx)
}

/// Mirrors `code_style.py::_group_plain_text` — reconstructs
/// `\code{...}` content preserving LaTeX special escapes, including
/// the `\?`-is-really-`\%` remap left by `neutralize::verbatim_args`
/// (see that function's doc comment).
fn group_plain_text(group: &GroupNode) -> String {
    let mut out = String::new();
    for child in &group.nodelist {
        match child {
            Node::Chars(c) => out.push_str(&c.chars),
            Node::Specials(s) => out.push_str(&s.chars),
            Node::Macro(m) if SINGLE_CHAR_ESCAPE_MACROS.contains(&m.macroname.as_str()) => {
                out.push_str(&m.macroname);
            }
            Node::Macro(m) if m.macroname == "?" => out.push('%'),
            _ => {}
        }
    }
    out.trim().to_string()
}