/**
 * Utilities for parsing VFX filenames into shot / task metadata.
 *
 * Expected naming convention (any separator count is fine):
 *   {SHOW}_{EP}_{SCENE}_{CUT}_{TASK}_{ARTIST}_v{NNN}.{ext}
 *   e.g.  UNG_106_035_010_cmp_TT_v002.mp4
 *
 * The shot code is matched against the database – the parser itself
 * does NOT hard-code how many underscore segments belong to the shot.
 */

export interface ParsedFilename {
  originalName: string;
  /** Filename without the extension */
  nameWithoutExt: string;
  /** Lowercased extension without the leading dot (e.g. "mp4", "mov") */
  ext: string;
  /**
   * Task name base – the full name without the version suffix.
   * e.g. "UNG_106_035_010_cmp_TT"
   */
  taskNameBase: string;
  /**
   * Full task title including the version suffix (no extension).
   * This is what the task should be named after upload.
   * e.g. "UNG_106_035_010_cmp_TT_v002"
   */
  taskNameWithVersion: string;
  /**
   * Version string extracted from the filename, e.g. "v002".
   * Empty string if no version pattern was found.
   */
  version: string;
  type: "mp4" | "mov" | "other";
}

/**
 * Parse a VFX filename into its constituent parts.
 */
export function parseFilename(filename: string): ParsedFilename {
  const lastDot = filename.lastIndexOf(".");
  const ext = lastDot >= 0 ? filename.slice(lastDot + 1).toLowerCase() : "";
  const nameWithoutExt = lastDot >= 0 ? filename.slice(0, lastDot) : filename;

  // Version pattern: _v followed by one or more digits at the end (case insensitive)
  const versionMatch = nameWithoutExt.match(/_v(\d+)$/i);
  const version = versionMatch ? `v${versionMatch[1]}` : "";
  const taskNameBase = versionMatch
    ? nameWithoutExt.slice(0, nameWithoutExt.length - versionMatch[0].length)
    : nameWithoutExt;

  const type: "mp4" | "mov" | "other" =
    ext === "mp4" ? "mp4" : ext === "mov" ? "mov" : "other";

  return {
    originalName: filename,
    nameWithoutExt,
    ext,
    taskNameBase,
    taskNameWithVersion: nameWithoutExt,
    version,
    type,
  };
}

/**
 * Strip a trailing version suffix (_v###) from a task title.
 * e.g. "UNG_106_035_010_cmp_TT_v001" → "UNG_106_035_010_cmp_TT"
 */
export function stripVersionFromTitle(title: string): string {
  return title.replace(/_v\d+$/i, "");
}

/**
 * Given a taskNameBase and a list of shot codes, return the shot code that
 * is a prefix of the task name base (shot code + "_" separator).
 *
 * e.g. taskNameBase "UNG_106_035_010_cmp_TT" matches shot "UNG_106_035_010"
 */
export function findMatchingShotCode(
  taskNameBase: string,
  shotCodes: string[]
): string | null {
  // Sort by length descending so longer (more specific) codes are matched first
  const sorted = [...shotCodes].sort((a, b) => b.length - a.length);
  for (const code of sorted) {
    if (
      taskNameBase === code ||
      taskNameBase.toLowerCase().startsWith(code.toLowerCase() + "_")
    ) {
      return code;
    }
  }
  return null;
}