import birl.{type Time}
import gleam/dict.{type Dict}
import gleam/option.{type Option}
import gleam/order.{type Order}
import lustre/element.{type Element}
import snag.{type Result}

/// A particular organization of pages, 
/// written either in custom markup or raw HTML.
/// A collection might be a set of products, or blog posts, or wiki entries.
/// A dedicated page can be generated to show off the pages in a collection,
/// and RSS feeds and whatnot can also be generated from the set of pages.
/// The pages are pulled from a particular directory,
/// and parsed and rendered a particular way,
/// that might be different from other collections.
/// See `arctic/collection` for more.
pub type Collection {
  Collection(
    directory: String,
    parse: fn(String, String) -> Result(Page),
    index: Option(fn(List(Page)) -> Element(Nil)),
    feed: Option(#(String, fn(List(Page)) -> String)),
    ordering: fn(Page, Page) -> Order,
    render: fn(Page) -> Element(Nil),
    raw_pages: List(RawPage),
  )
}

/// A single page in a collection.
/// These must have an ID to distinguish from other pages in the collection,
/// and a body of HTML elements.
/// Any other metadata can be added (stringly typed), 
/// and there are a variety of privileged metadata fields
/// like `.title` and `.date` that are actual typed properties.
/// However, these fields are optional.
/// See `arctic/page` for more.
pub type Page {
  Page(
    id: String,
    body: List(Element(Nil)),
    metadata: Dict(String, String),
    title: String,
    blerb: String,
    tags: List(String),
    date: Option(Time),
  )
}

/// A collection whose pages have been processed from the files.
pub type ProcessedCollection {
  ProcessedCollection(collection: Collection, pages: List(Page))
}

/// A page that is just HTML produced by hand.
pub type RawPage {
  RawPage(id: String, html: Element(Nil))
}

/// An Arctic configuration, describing all the collections, pages, parsing rules, etc.
pub type Config {
  Config(
    render_home: fn(List(ProcessedCollection)) -> Element(Nil),
    main_pages: List(RawPage),
    collections: List(Collection),
  )
}