import { z } from 'zod';

import { COMMENT_POLICIES } from './comments';

/**
 * Pond schemas and views shared between api and web (issue #21).
 * Ponds are the top-level content container; every self-registered
 * person owns exactly one personal pond (data-model.md §ponds).
 */

export const POND_TYPES = ['personal', 'shared'] as const;
export type PondType = (typeof POND_TYPES)[number];

export const SIDEBAR_SORT_MODES = ['alpha', 'created', 'manual'] as const;
export type SidebarSortMode = (typeof SIDEBAR_SORT_MODES)[number];

/** How the sidebar presents a pond's pages (issue #108): as the page tree
 * (`folders`) or grouped under the label tree (`labels`). */
export const SIDEBAR_VIEW_MODES = ['folders', 'labels'] as const;
export type SidebarViewMode = (typeof SIDEBAR_VIEW_MODES)[number];

/** One font slot per ADR 0016; values reference the curated catalog. */
const fontSlotSchema = z.object({
  family: z.string().min(1).max(80),
  weight: z.number().int().min(100).max(900),
});

/** The three font slots, each defaulted to the vision fonts (ADR 0016). */
export const pondFontsSchema = z.object({
  heading: fontSlotSchema.default({ family: 'Roboto', weight: 400 }),
  body: fontSlotSchema.default({ family: 'Roboto', weight: 200 }),
  mono: fontSlotSchema.default({ family: 'Fira Code', weight: 400 }),
});
export type PondFonts = z.infer<typeof pondFontsSchema>;

/**
 * Pond `settings` jsonb. Parsing `{}` yields the documented defaults
 * (sidebar sort `alpha`; fonts Roboto 400 / Roboto 200 / Fira Code,
 * ADR 0016) — persisted settings therefore only need to store what the
 * pond actually changed.
 */
/**
 * Pond accent theme (issue #186, ADR 0018 stage C): `null` inherits the
 * viewer's own theme. Only the accent family is pond-themable; the hex is
 * validated here, WCAG conformance arises at render time via
 * `deriveAccentTokens` — never as a server-side check.
 */
export const pondThemeSchema = z.object({
  accent: z
    .string()
    .regex(/^#[0-9a-f]{6}$/i, 'validation.invalid')
    .nullable()
    .default(null),
});
export type PondTheme = z.infer<typeof pondThemeSchema>;

export const pondSettingsSchema = z.object({
  sidebarSort: z.enum(SIDEBAR_SORT_MODES).default('alpha'),
  /** The pond default for the sidebar's page presentation (issue #108);
   * every member can override it locally (`ui.sidebar.view.<pondId>`). */
  sidebarView: z.enum(SIDEBAR_VIEW_MODES).default('folders'),
  fonts: pondFontsSchema.default({}),
  /** Who may write comments (issue #91): every reader, or editors only. */
  commentPolicy: z.enum(COMMENT_POLICIES).default('readers'),
  /** Per-pond opt-in to the public REST API (issue #104, default off):
   * without it the pond and its content answer 404 through the API even
   * for a token whose user could see them in the app. */
  apiEnabled: z.boolean().default(false),
  /** Per-pond opt-in to the built-in MCP endpoint (issue #105, default
   * off) — independent of the REST opt-in. */
  mcpEnabled: z.boolean().default(false),
  theme: pondThemeSchema.default({}),
});
export type PondSettings = z.infer<typeof pondSettingsSchema>;

/** The machine-access surfaces a pond can opt into (issues #104/#105). */
export type PondExposureFeature = 'api' | 'mcp';

export function pondFeatureEnabled(settings: PondSettings, feature: PondExposureFeature): boolean {
  return feature === 'api' ? settings.apiEnabled : settings.mcpEnabled;
}

export const pondNameSchema = z
  .string()
  .trim()
  .min(1, 'validation.required')
  .max(80, 'validation.tooLong');

export const createPondInputSchema = z.object({
  name: pondNameSchema,
  description: z.string().trim().max(500, 'validation.tooLong').default(''),
});
export type CreatePondInput = z.infer<typeof createPondInputSchema>;

export const updatePondInputSchema = z
  .object({
    name: pondNameSchema,
    description: z.string().trim().max(500, 'validation.tooLong'),
    sidebarSort: z.enum(SIDEBAR_SORT_MODES),
    sidebarView: z.enum(SIDEBAR_VIEW_MODES),
    fonts: pondFontsSchema,
    commentPolicy: z.enum(COMMENT_POLICIES),
    apiEnabled: z.boolean(),
    mcpEnabled: z.boolean(),
    theme: pondThemeSchema,
  })
  .partial();
export type UpdatePondInput = z.infer<typeof updatePondInputSchema>;

/** What the api returns for a pond; settings come fully defaulted. */
export interface PondView {
  id: string;
  slug: string;
  name: string;
  description: string;
  type: PondType;
  ownerId: string;
  settings: PondSettings;
  createdAt: string;
  deletedAt: string | null;
}

const MAX_SLUG_LENGTH = 60;

/**
 * Derives a URL-safe slug: German transliteration (ä→ae …), diacritics
 * stripped, everything else collapsed to single hyphens. Returns '' when
 * nothing survives — callers pick their fallback (e.g. the username).
 * Uniqueness (numeric suffixes) is the caller's job, not slugify's.
 */
export function slugify(input: string): string {
  return (
    input
      // Precompose first (#127): macOS file names arrive NFD-decomposed, and
      // the umlaut digraphs below only match the precomposed forms.
      .normalize('NFC')
      .toLowerCase()
      .replace(/ä/g, 'ae')
      .replace(/ö/g, 'oe')
      .replace(/ü/g, 'ue')
      .replace(/ß/g, 'ss')
      .normalize('NFKD')
      .replace(/[\u0300-\u036f]/g, '')
      .replace(/[^a-z0-9]+/g, '-')
      .replace(/^-+|-+$/g, '')
      .slice(0, MAX_SLUG_LENGTH)
      .replace(/-+$/, '')
  );
}