import type { IconType, ThemeType } from '../../types'

/**
 * A single board column. In **controlled / server mode** the caller supplies the
 * full array of columns (each owning its own `items` + `total`). In **group-by
 * mode** columns are derived from flat `data` and only `columnsDef` (id/title/…)
 * is needed for ordering & labels.
 */
export interface KanbanColumn<T = any> {
	id: string
	title: string
	items?: T[]
	/** Total available for this column (server mode). When set, "Load more" shows while items.length < total. */
	total?: number
	/** This column is currently fetching (server mode) — disables the load-more button + shows a spinner. */
	loading?: boolean
	color?: ThemeType
	icon?: IconType
}

/** Lean card field map — a board card has a fixed shape, unlike a table row. */
export interface KanbanCardSchema<T = any> {
	/** Field used as the card title (bold, first line). */
	title?: keyof T | ((item: T) => string)
	/** Optional secondary line. */
	subtitle?: keyof T | ((item: T) => string)
	/** Small monospace identifier shown in the footer (e.g. an id). */
	id?: keyof T | ((item: T) => string)
	/** Fields rendered as badges in the card body. */
	badges?: Array<keyof T | ((item: T) => { label: string; color?: ThemeType } | string | undefined)>
}

export interface KanbanMoveEvent<T = any> {
	item: T
	fromColumn: string
	toColumn: string
	/** Insertion index within the destination column. */
	newIndex: number
}

export interface KanbanBoardProps<T = any> {
	/* ── group-by mode ── */
	/** Flat data; provide with `groupBy` to derive columns client-side. */
	data?: T[]
	/** Field on each item that maps to a column id. */
	groupBy?: keyof T | ((item: T) => string)
	/** Column order + labels (group-by mode). Items not matching any def are dropped. */
	columnsDef?: KanbanColumn<T>[]

	/* ── controlled / server mode ── */
	/** Supplying `columns` switches the board to controlled (server) mode. */
	columns?: KanbanColumn<T>[]

	/** Stable key for each item (defaults to `item.id`). */
	itemKey?: keyof T | ((item: T) => string | number)

	/** Default card rendering. Ignored when the `#card` slot is used. */
	cardSchema?: KanbanCardSchema<T>

	/** Enable drag & drop between/within columns. The board stays controlled — handle `@move`. */
	draggable?: boolean

	/**
	 * Single load-more handler for every column. The board tracks the next page
	 * per column and calls this with the column id + page. The caller fetches and
	 * appends to that column's `items` (and updates `total`).
	 */
	loadMore?: (columnId: string, page: number) => void | Promise<void>

	/** Label for empty columns. */
	emptyText?: string
}