export type ParsedBlockReference = {
  sourceNoteId: string
  blockId: string
  raw: string
}

export type StoredBlockReference = ParsedBlockReference & {
  blockContent?: string
  sourceNoteTitle?: string
}

export const LAST_BLOCK_REF_SESSION_KEY = 'memento:lastBlockRef'

/** Référence bloc copiée via « Copier la référence » : /home?openNote=…#block-… */
export function parseBlockReferenceFromText(text: string): ParsedBlockReference | null {
  const trimmed = text.trim()
  if (!trimmed || trimmed.includes('\n')) return null

  const match = trimmed.match(/openNote=([^&#\s]+)(?:[^#]*?)#block-([a-zA-Z0-9_-]+)/i)
  if (!match) return null

  try {
    return {
      sourceNoteId: decodeURIComponent(match[1]),
      blockId: match[2],
      raw: trimmed,
    }
  } catch {
    return null
  }
}

export function rememberBlockReference(
  raw: string,
  extras?: { blockContent?: string; sourceNoteTitle?: string },
) {
  if (typeof sessionStorage === 'undefined') return
  const parsed = parseBlockReferenceFromText(raw)
  if (!parsed) return
  const payload: StoredBlockReference = {
    ...parsed,
    ...(extras?.blockContent ? { blockContent: extras.blockContent } : {}),
    ...(extras?.sourceNoteTitle ? { sourceNoteTitle: extras.sourceNoteTitle } : {}),
  }
  try {
    sessionStorage.setItem(LAST_BLOCK_REF_SESSION_KEY, JSON.stringify(payload))
  } catch {
    // quota / private mode
  }
}

export function recallLastBlockReference(): StoredBlockReference | null {
  if (typeof sessionStorage === 'undefined') return null
  try {
    const stored = sessionStorage.getItem(LAST_BLOCK_REF_SESSION_KEY)
    if (!stored) return null
    if (stored.startsWith('{')) {
      const payload = JSON.parse(stored) as StoredBlockReference
      if (payload?.sourceNoteId && payload?.blockId && payload?.raw) return payload
      return null
    }
    const parsed = parseBlockReferenceFromText(stored)
    return parsed ?? null
  } catch {
    return null
  }
}