const FIELD_HELP_BY_LABEL: Record<string, string> = {
  "API base URL": "Optional backend URL. Leave empty to use the current origin and the configured Vite/backend proxy.",
  "Automation API key": "Fallback API key for scripted or non-login access. Interactive browser sessions should use login tokens instead.",
  "Email": "Email address used to identify the user account for login or address entry.",
  "Password": "Password for the selected account or mail server. Stored and transmitted according to the configured backend flow.",
  "Name": "Human-readable display name shown in lists, reports or outgoing address headers.",
  "Email address": "The mailbox address, for example office@example.org.",

  "Campaign ID": "Stable technical identifier used in JSON, reports, filenames and backend references.",
  "Campaign name": "Human-readable campaign name shown in lists, review screens and reports.",
  "Mode": "Campaign operating mode. Use draft while editing, test for trial runs and send when preparing the real campaign.",
  "Scenario": "High-level campaign pattern used by guided setup to prefill sensible defaults.",
  "Description": "Internal explanation of the campaign purpose. This is not sent to recipients.",

  "Default From address": "Default sender address used for outgoing messages unless individual senders are allowed and set per recipient.",
  "From name": "Display name shown with the sender address in outgoing messages.",
  "From email": "Mailbox address used as the sender of outgoing messages.",
  "Global Reply-To address": "Default reply destination for recipient responses. Leave empty to let replies go to the From address.",
  "Reply-To": "Address recipients should reply to when it differs from the sender address.",
  "To": "Global To recipients added to every message in addition to recipient-specific recipients.",
  "Global recipients": "Default recipients included in every generated message.",
  "CC": "Global carbon-copy recipients included in every generated message.",
  "BCC": "Global blind-copy recipients included in every generated message.",

  "Template source": "Where this campaign template comes from. Inline means it is stored directly in the campaign draft.",
  "Library template": "Reusable template record this campaign should refer to once the template backend is available.",
  "Subject": "Message subject. Placeholders can reference campaign/global/recipient fields.",
  "Body": "Template body content shown for review. Placeholders are checked against campaign fields.",
  "Plain text body": "Plain text version of the email body. It should remain readable without HTML rendering.",
  "HTML body": "Optional HTML version of the email body for richer formatting.",

  "Attachment base path": "Base folder used to resolve campaign attachment rules and relative file patterns.",
  "Campaign attachment base path": "Base folder used during campaign creation to resolve attachment files and patterns.",
  "Default missing behavior": "Default review behavior when an expected attachment cannot be found.",
  "Default ambiguous behavior": "Default review behavior when a file pattern matches more than one attachment.",
  "Base directory": "Folder below the campaign attachment base path where this rule starts looking for files.",
  "File filter": "Filename or pattern used to select matching files. Field placeholders can be introduced later.",
  "Include subdirectories": "Whether the rule should also search below nested folders.",
  "Allow multiple matches": "Whether more than one matching file may be attached for this rule.",
  "Missing behavior": "Action or review severity when this rule finds no matching file.",
  "Ambiguous behavior": "Action or review severity when this rule finds multiple possible matches.",

  "Host": "Mail server hostname or IP address for the selected protocol.",
  "SMTP host": "SMTP server hostname or IP address used for sending messages.",
  "Port": "Network port used by the selected mail protocol.",
  "SMTP port": "Network port used by the SMTP server, commonly 587 for STARTTLS or 465 for TLS.",
  "Username": "Login name for the selected mail server. Often the same as the mailbox address.",
  "Security": "Connection security mode expected by the server: plain, TLS or STARTTLS.",
  "Timeout seconds": "Maximum time to wait for the mail server before the connection test or send attempt fails.",
  "Detected/saved sent folder": "IMAP folder name used as the detected or manually configured Sent folder.",
  "Append folder": "Folder where successfully sent messages should be appended via IMAP.",
  "IMAP append to Sent": "Whether sent messages should also be copied into the configured Sent folder via IMAP.",

  "Messages per minute": "Rate limit for outgoing messages. Lower values are safer for mail providers and throttled accounts.",
  "Concurrency": "Number of send operations that may run in parallel. Keep low until account and provider limits are clear.",
  "Max attempts": "Maximum retry attempts for a message before it remains failed for review.",

  "Source type": "Recipient data source format. Inline data is edited in the campaign; external sources will be parsed later.",
  "Source path": "Path or identifier for an external recipient source such as a CSV file.",

  "Remember previously used addresses": "Planned opt-in collection for autocomplete across campaigns. Currently autocomplete is campaign-local only.",
  "External address-book sync": "Placeholder for CardDAV, Google, LDAP or similar address sources.",
  "Allow individual senders": "Permit recipient rows to override the campaign's default sender address.",
  "Allow individual From": "Permit per-recipient sender overrides when building messages.",
  "Allow individual Reply-To": "Permit recipient rows to override the global Reply-To address.",
  "Allow individual To": "Permit recipient rows to define their own To recipients in addition to global headers.",
  "Allow individual CC": "Permit recipient rows to define their own CC recipients.",
  "Allow individual BCC": "Permit recipient rows to define their own BCC recipients.",
  "Allow individual attachments": "Permit recipient-specific attachment rules in addition to global files.",
  "Send without attachments": "Allow messages to be sent even when no attachment is resolved. Disable to force review or blocking.",
  "Status tracking": "Store per-message build, validation, queue, send and IMAP status for review and reporting.",
  "Suggest addresses from this campaign": "Use addresses already present in this campaign as autocomplete suggestions.",
  "Remember newly used addresses": "Prepare newly entered addresses for a future user-level address memory.",
  "Show guided warnings while editing": "Show inline guidance and warnings while campaign data is being edited.",
  "Required": "Mark this item as mandatory. Missing required data should become a validation or review issue.",
  "Subdirs": "Search nested folders below the configured base directory.",
  "Can override": "Allow recipient-specific values to override the global value for this field.",
  "Append successfully sent messages to Sent": "After SMTP send succeeds, append a copy of the message to the selected IMAP Sent folder.",
  "Append successful messages to Sent via IMAP": "After SMTP send succeeds, append a copy of the message to the configured IMAP Sent folder."
};

export function helpForFieldLabel(label: unknown): string | undefined {
  if (typeof label !== "string") return undefined;
  return FIELD_HELP_BY_LABEL[label];
}