/**
 * Turns lines typed (or pasted) onto the daily board into board items.
 *
 * The board replaces a shared doc, so the input is whatever someone would
 * have typed there:
 *
 *   WATER DROPS:
 *   DH2_VFX_027_210 still do (CHRIS)
 *   DH2_VFX_005_010 gfx required for update @michelle wait: client GFX ADH_GFX_005_020
 *
 * - The first shot-code-shaped token is the line's shot. It is matched against
 *   the project's shot codes and client aliases; a code that matches nothing
 *   is kept as typed so the board can flag it.
 * - `(NAME)` or `@name` assigns the line when NAME is a user's first or full
 *   name. A parenthesised group can carry more than the name — "(MICHELLE
 *   ROTO)" assigns Michelle and keeps "ROTO" in the text.
 * - `wait: …` (also `waiting on:`, `blocked by:`) marks what the line is
 *   blocked on. The colon is required so prose like "awaiting gfx" stays text.
 * - A line with no shot code that ends in ":" or is all capitals is a heading;
 *   the lines after it are grouped under it.
 */

export interface BoardShot {
  id: string;
  shotCode: string;
  clientCode?: string | null;
}

export interface BoardUser {
  id: string;
  name: string | null;
  email: string;
}

export interface ParsedBoardLine {
  text: string;
  /** The shot code as typed (canonical shotCode when it matched); null = no code on the line */
  code: string | null;
  shotId: string | null;
  assigneeId: string | null;
  waitingOn: string | null;
  group: string;
}

// Three or more underscore-separated segments, starting with a letter:
// DH2_VFX_027_090, UNG_117_023_010, ADH_GFX_005_020.
export const CODE_RE = /\b[A-Za-z][A-Za-z0-9]*(?:_[A-Za-z0-9]+){2,}\b/;
const WAIT_RE = /\b(?:wait(?:ing)?(?:\s+(?:on|for))?|blocked(?:\s+(?:on|by))?)\s*:\s*(.*)$/i;
const BULLET_RE = /^(?:[-*•–]|\d+[.)])\s+/;

export function findShot(code: string, shots: BoardShot[]): BoardShot | null {
  const c = code.toUpperCase();
  return (
    shots.find((s) => s.shotCode.toUpperCase() === c) ??
    shots.find((s) => s.clientCode?.trim().toUpperCase() === c) ??
    null
  );
}

/**
 * A likely intended shot for a code that matched nothing — same leading
 * segment and same numeric segments, so "DH2_004_100" suggests
 * "DH2_VFX_004_100". Only a unique candidate is suggested.
 */
export function suggestShot(code: string, shots: BoardShot[]): BoardShot | null {
  const sig = (c: string) => {
    const parts = c.toUpperCase().split("_");
    return `${parts[0]}|${parts.filter((p) => /^\d+$/.test(p)).join("_")}`;
  };
  const want = sig(code);
  if (want.endsWith("|")) return null; // no numeric segments to go on
  const hits = shots.filter((s) => sig(s.shotCode) === want);
  return hits.length === 1 ? hits[0] : null;
}

function userNames(u: BoardUser): string[] {
  const names = [u.email.split("@")[0]];
  if (u.name) {
    names.push(u.name);
    names.push(u.name.split(/\s+/)[0]);
  }
  return names.map((n) => n.toLowerCase());
}

function findUser(word: string, users: BoardUser[]): BoardUser | null {
  const w = word.toLowerCase();
  const hits = users.filter((u) => userNames(u).includes(w));
  return hits.length === 1 ? hits[0] : null;
}

function isHeading(line: string): boolean {
  if (CODE_RE.test(line)) return false;
  if (line.endsWith(":")) return true;
  const letters = line.replace(/[^A-Za-z]/g, "");
  return letters.length >= 3 && letters === letters.toUpperCase();
}

export function parseBoardLine(
  raw: string,
  ctx: { shots: BoardShot[]; users: BoardUser[] },
  group = "",
): ParsedBoardLine {
  let line = raw.trim().replace(BULLET_RE, "");

  let waitingOn: string | null = null;
  const wait = WAIT_RE.exec(line);
  if (wait) {
    waitingOn = wait[1].trim() || null;
    line = line.slice(0, wait.index);
  }

  let code: string | null = null;
  let shotId: string | null = null;
  const codeMatch = CODE_RE.exec(line);
  if (codeMatch) {
    const shot = findShot(codeMatch[0], ctx.shots);
    code = shot?.shotCode ?? codeMatch[0].toUpperCase();
    shotId = shot?.id ?? null;
    line = line.slice(0, codeMatch.index) + line.slice(codeMatch.index + codeMatch[0].length);
  }

  let assigneeId: string | null = null;
  // (NAME …) — first word a user's name; the rest of the group stays as text
  line = line.replace(/\(([^)]*)\)/g, (whole, inner: string) => {
    if (assigneeId) return whole;
    const words = inner.trim().split(/\s+/);
    // Full name first ("Chris Pinto"), then first word
    const full = findUser(words.slice(0, 2).join(" "), ctx.users);
    const user = full ?? findUser(words[0] ?? "", ctx.users);
    if (!user) return whole;
    assigneeId = user.id;
    const rest = words.slice(full ? 2 : 1).join(" ");
    return rest ? ` ${rest} ` : " ";
  });
  line = line.replace(/@([A-Za-z][\w.-]*)/g, (whole, name: string) => {
    if (assigneeId) return whole;
    const user = findUser(name, ctx.users);
    if (!user) return whole;
    assigneeId = user.id;
    return " ";
  });

  const text = line
    .replace(/\s+/g, " ")
    .replace(/^[\s:\-–,.]+|[\s:\-–,]+$/g, "")
    .trim();

  return { text, code, shotId, assigneeId, waitingOn, group };
}

/** Every non-blank line of `input` as a board item, headings applied as groups. */
export function parseBoardText(
  input: string,
  ctx: { shots: BoardShot[]; users: BoardUser[]; group?: string },
): ParsedBoardLine[] {
  const out: ParsedBoardLine[] = [];
  let group = ctx.group ?? "";
  const lines = input.split(/\r?\n/).map((l) => l.trim()).filter(Boolean);
  for (const raw of lines) {
    const line = raw.replace(BULLET_RE, "");
    // A single line is always an item — someone typing "Deposit received"
    // into the quick-add box means a note, not a heading.
    if (lines.length > 1 && isHeading(line)) {
      group = line.replace(/:$/, "").trim();
      continue;
    }
    const parsed = parseBoardLine(line, ctx, group);
    if (parsed.text || parsed.code || parsed.waitingOn) out.push(parsed);
  }
  return out;
}