//! Lightweight meeting-process detection.
//!
//! Scope (per Jake's ideology note): single signal only — poll the process
//! list and match user-editable patterns. No mic-activity heuristic, no
//! calendar integration. If the user opts in, we surface a non-modal toast
//! so they can decide to start recording. We never start recording
//! ourselves from this signal.

use sysinfo::{ProcessRefreshKind, ProcessesToUpdate, RefreshKind, System};

/// Snapshot the current process list's executable/command names. Lowercased
/// for case-insensitive pattern matching.
pub fn list_running_process_names() -> Vec<String> {
    let mut system = System::new_with_specifics(
        RefreshKind::nothing().with_processes(ProcessRefreshKind::nothing()),
    );
    system.refresh_processes(ProcessesToUpdate::All, true);
    system
        .processes()
        .values()
        .map(|process| process.name().to_string_lossy().to_lowercase())
        .collect()
}

/// Match a snapshot of process names against case-insensitive substring
/// `patterns`. Returns the set of patterns that matched at least once, in
/// input order, deduped. Empty / whitespace-only patterns are skipped so
/// a stray blank entry in the user's list never matches everything.
pub fn match_meeting_patterns(process_names: &[String], patterns: &[String]) -> Vec<String> {
    let mut matches: Vec<String> = Vec::new();
    for raw_pattern in patterns {
        let needle = raw_pattern.trim().to_lowercase();
        if needle.is_empty() {
            continue;
        }
        if process_names.iter().any(|name| name.contains(&needle))
            && !matches.iter().any(|existing| existing == &needle)
        {
            matches.push(needle);
        }
    }
    matches
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn matches_are_case_insensitive_substrings() {
        let processes = vec![
            "Zoom Meeting".to_lowercase(),
            "firefox".to_lowercase(),
            "Microsoft Teams".to_lowercase(),
        ];
        let patterns = vec!["ZOOM".into(), "teams".into(), "discord".into()];

        let got = match_meeting_patterns(&processes, &patterns);

        assert_eq!(got, vec!["zoom", "teams"]);
    }

    #[test]
    fn empty_and_whitespace_patterns_are_ignored() {
        let processes = vec!["anything".to_lowercase()];
        let patterns = vec!["".into(), "   ".into()];

        assert!(match_meeting_patterns(&processes, &patterns).is_empty());
    }

    #[test]
    fn matches_are_deduped() {
        let processes = vec!["zoomclient".into(), "zoomhelper".into()];
        let patterns = vec!["zoom".into(), "zoom".into()];

        assert_eq!(match_meeting_patterns(&processes, &patterns), vec!["zoom"]);
    }

    #[test]
    fn list_running_returns_something_on_this_host() {
        // Smoke check — this is the test host and always has running procs.
        let names = list_running_process_names();
        assert!(!names.is_empty(), "expected at least one running process");
    }
}