trusty-analyze 0.7.2

//! Blocking diagnostics dispatch logic for `GET /indexes/{id}/diagnostics`.
//!
//! Why: the dispatch logic grew with Phase 1 (project-scoped tool support) to
//! the point where keeping it in `service/mod.rs` would push that file past
//! its 500-line-cap allowlist budget. Extracting it here keeps each file
//! focused: `mod.rs` owns the axum handler wiring; this module owns the
//! "how to run tools against an index corpus" logic.
//! What: exports `run_diagnostics_blocking`, which is called from
//! `diagnostics_for_index` under `tokio::task::spawn_blocking`. The function
//! splits tools into file-scoped (scratch dir) and project-scoped (real disk)
//! buckets and dispatches each correctly.
//! Test: `run_diagnostics_blocking_skips_unknown_languages`,
//! `run_diagnostics_blocking_respects_language_filter`, and
//! `run_diagnostics_blocking_project_scoped_skips_when_no_root` in
//! `service/mod.rs` exercise this via the public interface.

use std::collections::HashMap;
use std::path::Path;

use crate::core::{DiagnosticsReport, ToolDiagnostic};

/// Abs-to-rel mapping: given the absolute on-disk path of a diagnostic and
/// the `(rel, real)` pairs for the current language bucket, return the
/// index-relative path to use for `diag.file`, or `None` if no match.
///
/// Why: project-scoped tools (Roslyn) emit absolute paths; the caller needs
/// to map them back to the index-relative paths that the HTTP response uses.
/// What: tries exact equality first, then a component-anchored suffix match.
/// The suffix branches strip the leading `/` from absolute paths before
/// building the format string to avoid the `//…` double-slash trap: when
/// `real` = `/home/user/proj/src/Foo.cs`, naively forming `"/{real}"` yields
/// `"//home/user/proj/src/Foo.cs"` which no absolute path ever ends with.
/// Without the strip, both suffix branches are logically dead when `real` is
/// absolute (which it always is — it is `Path::new(root).join(rel)`), so any
/// case where exact equality fails (symlink resolution, case differences on a
/// case-insensitive FS like macOS) silently drops all diagnostics.
/// Test: `abs_to_rel_exact_match`, `abs_to_rel_suffix_match_absolute_real`,
/// and `abs_to_rel_no_match_returns_none` in `diagnostics_dispatch_tests.rs`.
pub(crate) fn abs_to_rel<'a>(
    abs_diag_file: &str,
    rel_real_pairs: &'a [(String, String)],
) -> Option<&'a str> {
    for (rel, real) in rel_real_pairs {
        // Exact match — the common production path.
        if abs_diag_file == real.as_str() || abs_diag_file == rel.as_str() {
            return Some(rel.as_str());
        }
        // Component-anchored suffix match. We strip the leading `/` from
        // absolute `real` and `rel` before interpolating into the format
        // string so we get `"/suffix"` not `"//suffix"`.
        let real_suffix = real.trim_start_matches('/');
        let rel_suffix = rel.trim_start_matches('/');
        if abs_diag_file.ends_with(&format!("/{real_suffix}"))
            || abs_diag_file.ends_with(&format!("/{rel_suffix}"))
            || real.ends_with(&format!("/{abs_diag_file}"))
            || rel.ends_with(&format!("/{abs_diag_file}"))
        {
            return Some(rel.as_str());
        }
    }
    None
}

/// Blocking core of the diagnostics endpoint, using the process-wide global
/// tool registry.
///
/// Why: the production call site uses the global (lazily-discovered) registry
/// of whatever tools are installed on the host. Returns a `DiagnosticsReport`
/// so callers can distinguish "ran tools, found nothing" from "no tools
/// available" (#915).
/// What: delegates to `run_diagnostics_blocking_with_registry` with
/// `global_registry()`.
/// Test: `run_diagnostics_blocking_skips_unknown_languages`,
/// `run_diagnostics_blocking_respects_language_filter`.
pub fn run_diagnostics_blocking(
    by_file: HashMap<String, String>,
    language_filter: Option<String>,
    tool_filter: Option<Vec<String>>,
    root_path: Option<String>,
) -> DiagnosticsReport {
    use crate::core::global_registry;
    run_diagnostics_blocking_with_registry(
        by_file,
        language_filter,
        tool_filter,
        root_path,
        global_registry(),
    )
}

/// Registry-parameterized version of the blocking diagnostics dispatch.
///
/// Why: tests need to inject a synthetic `ToolRegistry` (containing fake
/// project-scoped tools that count `run_project` invocations) to assert the
/// skip-when-no-root contract is actually enforced rather than just not
/// panicking. Returns `DiagnosticsReport` to distinguish "ran tools, found
/// nothing" from "no tools available" (#915).
/// What: same dispatch logic as the production path, but accepts any
/// `&ToolRegistry` instead of always using `global_registry()`.
///   1. Groups `by_file` entries by language (honouring `language_filter`).
///   2. For each language, splits available tools into project-scoped and
///      file-scoped buckets (honouring `tool_filter` by name in both).
///   3. File-scoped tools: write each file to a unique numeric subdirectory
///      under the scratch tempdir (keyed by loop index), call
///      `tool.run(scratch_path, content)`, rewrite `diag.file` back to the
///      index-relative path. The per-file subdir prevents basename collisions:
///      two files `src/a/main.rs` and `src/b/main.rs` have the same basename
///      but different indices, so they never overwrite each other.
///   4. Project-scoped tools: only if `root_path` is `Some`. Build real
///      on-disk paths by joining `root` with the rel path; keep only those
///      that `exist()`. Call `tool.run_project(&real_paths)`. Map each
///      `diag.file` (absolute) back to the index-relative rel via
///      `abs_to_rel`. Drop diagnostics that don't map to any indexed file.
///      When `root_path` is `None`, log at info and skip (graceful degradation).
///   5. Returns a `DiagnosticsReport` with `tools_run`, `tools_unavailable`,
///      and `diagnostics` populated.
///
/// Test: `run_diagnostics_blocking_project_scoped_skips_when_no_root` uses
/// this directly with a `FakeProjectScopedTool` registry.
/// `run_diagnostics_blocking_with_registry_two_files_same_basename` (below)
/// proves the per-file subdir isolation prevents basename collisions.
/// `report_marks_unavailable_tool` proves that tools absent from PATH are
/// reported under `tools_unavailable`.
pub fn run_diagnostics_blocking_with_registry(
    by_file: HashMap<String, String>,
    language_filter: Option<String>,
    tool_filter: Option<Vec<String>>,
    root_path: Option<String>,
    registry: &crate::core::tool_registry::ToolRegistry,
) -> DiagnosticsReport {
    use crate::lang::LanguageDetector;

    // Collect unavailable tool names from the registry upfront.
    let tools_unavailable: Vec<String> = registry.unavailable_names().to_vec();

    let scratch = match tempfile::tempdir() {
        Ok(d) => d,
        Err(e) => {
            tracing::warn!("failed to create scratch dir for diagnostics: {e}");
            return DiagnosticsReport {
                tools_run: Vec::new(),
                tools_unavailable,
                diagnostics: Vec::new(),
            };
        }
    };

    // Group by language, applying the language filter.
    let mut by_lang: HashMap<String, Vec<(String, String)>> = HashMap::new();
    for (file, content) in by_file {
        let Some(lang) = LanguageDetector::detect_file(&file) else {
            continue;
        };
        if let Some(want) = &language_filter {
            if &lang != want {
                continue;
            }
        }
        by_lang.entry(lang).or_default().push((file, content));
    }

    let mut out: Vec<ToolDiagnostic> = Vec::new();
    // Deduplicated set of tool names that were actually invoked.
    let mut tools_run_set: std::collections::HashSet<String> = std::collections::HashSet::new();

    for (lang, file_pairs) in &by_lang {
        let tools = registry.tools_for(lang);
        if tools.is_empty() {
            continue;
        }

        // Split tools into project-scoped and file-scoped, honouring tool_filter.
        let mut proj_tools: Vec<std::sync::Arc<dyn crate::core::tools::StaticTool>> = Vec::new();
        let mut file_tools: Vec<std::sync::Arc<dyn crate::core::tools::StaticTool>> = Vec::new();
        for tool in tools {
            if let Some(names) = &tool_filter {
                if !names.iter().any(|n| n == tool.name()) {
                    continue;
                }
            }
            if tool.is_project_scoped() {
                proj_tools.push(tool);
            } else {
                file_tools.push(tool);
            }
        }

        // --- FILE-SCOPED tools (original scratch-dir behavior) ---
        if !file_tools.is_empty() {
            // Use an incrementing counter so each file gets a unique scratch
            // subdir. This prevents basename collisions: `src/a/main.rs` and
            // `src/b/main.rs` both have basename `main.rs`, so without a
            // unique subdir the second write overwrites the first and its
            // diagnostics are silently lost. The fix mirrors commit 16cd8eac
            // (closes #976) that applied the same isolation to
            // `run_diagnostics_blocking` in `handlers/analysis.rs`.
            for (idx, (rel_file, content)) in file_pairs.iter().enumerate() {
                let name = Path::new(rel_file)
                    .file_name()
                    .map(|n| n.to_string_lossy().into_owned())
                    .unwrap_or_else(|| "chunk.txt".to_string());
                // Unique numeric subdir prevents basename collisions.
                let file_dir = scratch.path().join(idx.to_string());
                if let Err(e) = std::fs::create_dir_all(&file_dir) {
                    tracing::warn!("failed to create scratch subdir for {name}: {e}");
                    continue;
                }
                let path = file_dir.join(&name);
                if let Err(e) = std::fs::write(&path, content) {
                    tracing::warn!("failed to write scratch file {name}: {e}");
                    continue;
                }
                for tool in &file_tools {
                    tools_run_set.insert(tool.name().to_string());
                    let result = tool.run(&path, content);
                    match result {
                        Ok(mut diags) => {
                            for d in &mut diags {
                                d.file = rel_file.clone();
                            }
                            out.extend(diags);
                        }
                        Err(e) => tracing::warn!("diagnostics for {rel_file} failed: {e:#}"),
                    }
                }
            }
        }

        // --- PROJECT-SCOPED tools (real on-disk paths) ---
        if proj_tools.is_empty() {
            continue;
        }
        let root = match &root_path {
            Some(r) => r,
            None => {
                // Raise to info so operators see why C# diagnostics return
                // zero without setting RUST_LOG=debug. The usual cause is that
                // the index was not fetched with ?details=true, so root_path
                // was not included in the corpus response — an operational
                // misconfiguration, not a normal code path.
                tracing::info!(
                    "project-scoped tools available for {lang} but root_path is None; \
                     skipping (index was not fetched with ?details=true — \
                     C# diagnostics will be empty until root_path is available)"
                );
                continue;
            }
        };

        // Build real paths and keep only those that exist on disk.
        let rel_real_pairs: Vec<(String, String)> = file_pairs
            .iter()
            .filter_map(|(rel, _)| {
                let real = Path::new(root).join(rel);
                if real.exists() {
                    Some((rel.clone(), real.to_string_lossy().into_owned()))
                } else {
                    None
                }
            })
            .collect();

        if rel_real_pairs.is_empty() {
            tracing::debug!(
                "project-scoped tools for {lang}: no files exist under root {root}; skipping"
            );
            continue;
        }

        let real_paths: Vec<std::path::PathBuf> = rel_real_pairs
            .iter()
            .map(|(_, real)| std::path::PathBuf::from(real))
            .collect();

        for tool in &proj_tools {
            tools_run_set.insert(tool.name().to_string());
            match tool.run_project(&real_paths) {
                Ok(diags) => {
                    for mut diag in diags {
                        match abs_to_rel(&diag.file, &rel_real_pairs) {
                            Some(rel) => {
                                diag.file = rel.to_string();
                                out.push(diag);
                            }
                            None => {
                                // Diagnostic for a file outside the indexed set — drop.
                                tracing::debug!(
                                    "dropping project-scoped diag for unmapped file: {}",
                                    diag.file
                                );
                            }
                        }
                    }
                }
                Err(e) => {
                    tracing::warn!("project-scoped diagnostics ({}) failed: {e:#}", tool.name())
                }
            }
        }
    }

    let mut tools_run: Vec<String> = tools_run_set.into_iter().collect();
    tools_run.sort();

    DiagnosticsReport {
        tools_run,
        tools_unavailable,
        diagnostics: out,
    }
}

#[cfg(test)]
#[path = "diagnostics_dispatch_tests.rs"]
mod tests;