import type { ImportableSchemaBase, CollectionSchemaBase, SchemaBase } from './dsl.js';
import { DtoField } from './dto.js';
import type { DtoMessage, DtoArrayField, DtoObjectField } from './dto.js';
import type { ComponentSchema } from './component.js';
import type { PageActionSchema } from './page-action.js';

export type { RouteDataSchema } from './route.js';
export { defineRouteData } from './route.js';

// PageDef: a page skeleton declaration. Describes what data a page needs
// and where each field comes from (route params, provider calls, or literals).
// Driver identifies the source by inspecting each field's .schema back-reference.

/** Page lifecycle events that trigger data loading. */
export interface EventSchema extends SchemaBase {
  type: 'onLoad' | 'onShow' | 'onHide' | 'onPullDownRefresh' | 'onReachBottom';
  /** Page actions that fire when this event occurs. */
  actions?: PageActionSchema[];
}

export const events = {
  onLoad(actions?: PageActionSchema[], description?: string): EventSchema {
    return { name: 'onLoad', type: 'onLoad', actions, description };
  },
  onShow(actions?: PageActionSchema[], description?: string): EventSchema {
    return { name: 'onShow', type: 'onShow', actions, description };
  },
  onHide(actions?: PageActionSchema[], description?: string): EventSchema {
    return { name: 'onHide', type: 'onHide', actions, description };
  },
  onPullDownRefresh(actions?: PageActionSchema[], description?: string): EventSchema {
    return { name: 'onPullDownRefresh', type: 'onPullDownRefresh', actions, description };
  },
  onReachBottom(actions?: PageActionSchema[], description?: string): EventSchema {
    return { name: 'onReachBottom', type: 'onReachBottom', actions, description };
  },
};

/** Page data: a named collection of fields that defines the page's data shape. */
export interface PageDataSchema extends CollectionSchemaBase {
  type: 'pageData';
  fields: Record<string, DtoField | DtoMessage | DtoArrayField | DtoObjectField>;
}

export function definePageData(fields: PageDataSchema['fields']): PageDataSchema {
  // Page data has no meaningful identity of its own; the page name already
  // scopes it, so the schema name defaults to 'data'.
  const data: PageDataSchema = { name: 'data', type: 'pageData', fields };
  // Write back field names (same convention as buildMessage) so defineRef
  // produces refs with a real field name instead of ''.
  for (const key of Object.keys(data.fields)) {
    const df = data.fields[key];
    if (df instanceof DtoField) {
      df.name = key;
      df.schema = data;
    }
  }
  return data;
}

/** Page skeleton definition. */
export interface PageDef extends ImportableSchemaBase {
  data: PageDataSchema;
  /** Lifecycle events that trigger data loading. */
  events: EventSchema[];
  /** Page actions (provider calls, navigation, etc.). */
  actions: PageActionSchema[];
  /** UI component declarations that make up the page skeleton. */
  components: ComponentSchema[];
  /** Whether the driver should generate page-level loading / error / empty state wrappers. */
  handleStates?: boolean;
}

/** Define a page skeleton. */
export function definePageDef(
  name: string,
  schema: Omit<PageDef, 'name'>,
): PageDef {
  return { name, ...schema };
}