import common::config;
import io::ReaderUtil;

export load_errors;
export expected_error;

type expected_error = { line: uint, kind: ~str, msg: ~str };

// Load any test directives embedded in the file
fn load_errors(testfile: &Path) -> ~[expected_error] {
    let mut error_patterns = ~[];
    let rdr = result::get(io::file_reader(testfile));
    let mut line_num = 1u;
    while !rdr.eof() {
        let ln = rdr.read_line();
        error_patterns += parse_expected(line_num, ln);
        line_num += 1u;
    }
    return error_patterns;
}

fn parse_expected(line_num: uint, line: ~str) -> ~[expected_error] unsafe {
    let error_tag = ~"//~";
    let mut idx;
    match str::find_str(line, error_tag) {
      option::none => return ~[],
      option::some(nn) => { idx = (nn as uint) + str::len(error_tag); }
    }

    // "//~^^^ kind msg" denotes a message expected
    // three lines above current line:
    let mut adjust_line = 0u;
    let len = str::len(line);
    while idx < len && line[idx] == ('^' as u8) {
        adjust_line += 1u;
        idx += 1u;
    }

    // Extract kind:
    while idx < len && line[idx] == (' ' as u8) { idx += 1u; }
    let start_kind = idx;
    while idx < len && line[idx] != (' ' as u8) { idx += 1u; }
    let kind = str::to_lower(str::slice(line, start_kind, idx));

    // Extract msg:
    while idx < len && line[idx] == (' ' as u8) { idx += 1u; }
    let msg = str::slice(line, idx, len);

    debug!("line=%u kind=%s msg=%s", line_num - adjust_line, kind, msg);

    return ~[{line: line_num - adjust_line, kind: kind, msg: msg}];
}