// Capitalisation helpers for the free-text QSO fields (Name / QTH / Comment /
// Note).
//
// The same station reaches the log SHOUTED by QRZ, lower-cased by a hurried
// operator, and in whatever case the other logger stored it in an imported
// ADIF — so one callsign ends up as "JEAN", "jean" and "Jean" across a log,
// and sorting or reading a QTH column becomes a mess.
//
// Both helpers are meant to run on BLUR, never per keystroke: rewriting the
// value while the operator is still typing a word fights them mid-word (see
// the controlled-input note in CLAUDE.md).

// titleCase upper-cases the first letter of every word and lower-cases the
// rest. Separators are kept, so "SAINT-JULIEN" → "Saint-Julien" and
// "o'brien" → "O'Brien".
export function titleCase(s: string): string {
  return s
    .toLowerCase()
    .replace(/(^|[\s\-'’/.])(\p{L})/gu, (_m, sep: string, ch: string) => sep + ch.toUpperCase());
}

// sentenceCase upper-cases the first letter and leaves everything after it as
// typed. A comment routinely carries callsigns, modes and abbreviations
// ("TNX QSO F5ABC, FT8 59") that lower-casing would quietly destroy — which is
// why this is NOT titleCase.
export function sentenceCase(s: string): string {
  return s.replace(/^(\s*)(\p{L})/u, (_m, sp: string, ch: string) => sp + ch.toUpperCase());
}