tldr-core 0.1.3

//! TypeScript Compiler (tsc) text output parser.
//!
//! tsc outputs text in the following format (no native JSON):
//! ```text
//! src/auth.ts(42,5): error TS2339: Property 'foo' does not exist on type 'Bar'.
//! ```
//!
//! Pattern: `file(line,col): severity TScode: message`

use crate::diagnostics::{Diagnostic, Severity};
use crate::error::TldrError;
use regex::Regex;
use std::path::PathBuf;

/// Get the regex pattern for parsing tsc output lines.
///
/// Pattern captures:
/// 1. File path
/// 2. Line number
/// 3. Column number
/// 4. Severity (error/warning)
/// 5. Error code (TS####)
/// 6. Message
pub fn tsc_output_regex() -> Regex {
    // Pattern: file(line,col): severity TScode: message
    Regex::new(r"^(.+)\((\d+),(\d+)\):\s*(error|warning)\s+(TS\d+):\s*(.+)$")
        .expect("Invalid tsc regex pattern")
}

/// Parse tsc text output into unified Diagnostic structs.
///
/// # Arguments
/// * `output` - The raw text output from `tsc --noEmit --pretty false`
///
/// # Returns
/// A vector of Diagnostic structs, or an error if parsing fails.
pub fn parse_tsc_text(output: &str) -> Result<Vec<Diagnostic>, TldrError> {
    let regex = tsc_output_regex();
    let mut diagnostics = Vec::new();

    for line in output.lines() {
        let line = line.trim();
        if line.is_empty() {
            continue;
        }

        if let Some(captures) = regex.captures(line) {
            let file = captures.get(1).map(|m| m.as_str()).unwrap_or("");
            let line_num: u32 = captures
                .get(2)
                .and_then(|m| m.as_str().parse().ok())
                .unwrap_or(1);
            let column: u32 = captures
                .get(3)
                .and_then(|m| m.as_str().parse().ok())
                .unwrap_or(1);
            let severity_str = captures.get(4).map(|m| m.as_str()).unwrap_or("error");
            let code = captures.get(5).map(|m| m.as_str().to_string());
            let message = captures
                .get(6)
                .map(|m| m.as_str())
                .unwrap_or("")
                .to_string();

            let severity = match severity_str.to_lowercase().as_str() {
                "error" => Severity::Error,
                "warning" => Severity::Warning,
                _ => Severity::Error,
            };

            diagnostics.push(Diagnostic {
                file: PathBuf::from(file),
                line: line_num,
                column,
                end_line: None,
                end_column: None,
                severity,
                message,
                code,
                source: "tsc".to_string(),
                url: None,
            });
        }
        // Lines that don't match the pattern are ignored (e.g., continuation lines)
    }

    Ok(diagnostics)
}

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

    #[test]
    fn test_parse_error() {
        let output =
            "src/auth.ts(42,5): error TS2339: Property 'foo' does not exist on type 'Bar'.";

        let result = parse_tsc_text(output).unwrap();
        assert_eq!(result.len(), 1);

        let d = &result[0];
        assert_eq!(d.file, PathBuf::from("src/auth.ts"));
        assert_eq!(d.line, 42);
        assert_eq!(d.column, 5);
        assert_eq!(d.severity, Severity::Error);
        assert_eq!(d.code, Some("TS2339".to_string()));
        assert_eq!(d.source, "tsc");
    }

    #[test]
    fn test_parse_warning() {
        let output = "src/utils.ts(15,1): warning TS6385: 'x' is deprecated.";

        let result = parse_tsc_text(output).unwrap();
        assert_eq!(result.len(), 1);

        let d = &result[0];
        assert_eq!(d.severity, Severity::Warning);
        assert_eq!(d.code, Some("TS6385".to_string()));
    }

    #[test]
    fn test_parse_multiple() {
        let output = r#"src/auth.ts(42,5): error TS2339: Property 'foo' does not exist.
src/auth.ts(58,10): error TS2345: Argument type mismatch.
src/utils.ts(15,1): warning TS6385: Deprecated."#;

        let result = parse_tsc_text(output).unwrap();
        assert_eq!(result.len(), 3);
    }

    #[test]
    fn test_empty_output() {
        let result = parse_tsc_text("").unwrap();
        assert!(result.is_empty());
    }

    #[test]
    fn test_regex_pattern() {
        let regex = tsc_output_regex();
        let line = "src/auth.ts(42,5): error TS2339: Property 'foo' does not exist on type 'Bar'.";
        let captures = regex.captures(line).unwrap();

        assert_eq!(captures.get(1).unwrap().as_str(), "src/auth.ts");
        assert_eq!(captures.get(2).unwrap().as_str(), "42");
        assert_eq!(captures.get(3).unwrap().as_str(), "5");
        assert_eq!(captures.get(4).unwrap().as_str(), "error");
        assert_eq!(captures.get(5).unwrap().as_str(), "TS2339");
    }
}