# Activity Metadata Schema
#
# Extends PostMetadata with activity-specific fields (talks, workshops, events).
# The `metadata` field carries event-specific data: type, location, slides, downloads.
#
# Usage — preferred (make_activity factory):
#
#   let schema = import "content/metadata/activity_metadata.ncl" in
#   schema.make_activity {
#     id       = "rust-async-patterns-2026",
#     title    = "Rust Async Patterns in Production",
#     slug     = "rust-async-patterns",
#     date     = "2026-03-15",
#     category = "talks",
#   }

let c    = import "contracts.ncl" in
let post = import "post_metadata.ncl" in
let d    = import "defaults.ncl" in

{
  ActivityEventMetadata = {
    event_type
      | String
      | doc "Activity kind: 'talk' | 'workshop' | 'webinar' | 'panel' | 'other'"
      | optional,

    event_date
      | String
      | c.DateContract
      | doc "Date of the event (ISO 8601). May differ from the post date."
      | optional,

    event_location
      | String
      | doc "City or venue name. Empty string or absent for online events."
      | optional,

    slides_id
      | String
      | doc "Identifier used to derive the slides URL or file path."
      | optional,

    pdf_filename
      | String
      | doc "Filename of the downloadable PDF (relative to the slides asset directory)."
      | optional,

    repository_url
      | String
      | doc "URL to the companion source code repository."
      | optional,

    questionnaire_type
      | String
      | doc "Gating mechanism for downloads: 'internal' | 'external' | 'none'."
      | optional,

    questionnaire_config
      | String
      | doc "Identifier of the questionnaire configuration used for gating."
      | optional,

    download_requires_auth
      | Bool
      | doc "Require authenticated session before allowing download."
      | default = false,

    download_requires_questionnaire
      | Bool
      | doc "Require questionnaire completion before allowing download."
      | default = false,

    gallery
      | Array String
      | doc "List of image filenames or URLs for the activity photo gallery."
      | default = [],

    ..
  },

  ActivityMetadata = post.PostMetadata & {
    sort_order
      | Number
      | doc "Display order within the category listing. Lower values appear first."
      | default = 100,

    metadata
      | ActivityEventMetadata
      | doc "Activity-specific event metadata (location, slides, downloads, etc.)."
      | default = {},
  },

  make_activity
    | not_exported
    | doc "Create a validated activity metadata record. Provide at minimum: title, slug, date, category."
    = fun overrides =>
        d & overrides | ActivityMetadata,
}