import * as z from "zod";
import { UserFactCategorySchema, UserFactSchema, UserProfileSchema } from "./domain.js";
import { Id } from "./ids.js";

export const USER_FACT_VALUE_MAX_LENGTH = 500;
export const USER_COMMUNICATION_STYLE_MAX_LENGTH = 500;
export const USER_PROFILE_SUMMARY_MAX_LENGTH = 4_000;

/** True when `value` is an IANA time zone this runtime can format, e.g. "Europe/Vienna". */
export function isTimeZone(value: string): boolean {
  try {
    new Intl.DateTimeFormat("en-US", { timeZone: value });
    return true;
  } catch {
    return false;
  }
}

/** True when `value` is a well-formed BCP-47 language tag, e.g. "de" or "pt-BR". */
export function isLanguageTag(value: string): boolean {
  try {
    return Intl.getCanonicalLocales(value).length === 1;
  } catch {
    return false;
  }
}

/** An IANA time zone, stored in its canonical spelling. */
export const TimeZoneSchema = z
  .string()
  .trim()
  .min(1)
  .max(64)
  .refine(isTimeZone, "Unknown time zone")
  .transform(
    (value) => new Intl.DateTimeFormat("en-US", { timeZone: value }).resolvedOptions().timeZone,
  );

/** A BCP-47 language tag, stored in its canonical spelling. */
export const LanguageTagSchema = z
  .string()
  .trim()
  .min(2)
  .max(35)
  .refine(isLanguageTag, "Invalid language tag")
  .transform((value) => Intl.getCanonicalLocales(value)[0] ?? value);

export const UserFactValueSchema = z.string().trim().min(1).max(USER_FACT_VALUE_MAX_LENGTH);

/** null shows a fact in every space; a list limits it to those spaces. */
const UserFactSpaceIds = z.array(Id).min(1).max(32).nullable();

export const UserProfileStateSchema = z.object({
  profile: UserProfileSchema,
  facts: z.array(UserFactSchema),
});
export type UserProfileState = z.infer<typeof UserProfileStateSchema>;

export const NewUserFactInput = z.object({
  category: UserFactCategorySchema,
  value: UserFactValueSchema,
  /** Answers given during onboarding keep that origin; anything else the user adds is "user". */
  source: z.enum(["user", "onboarding"]).default("user"),
  spaceIds: UserFactSpaceIds.optional(),
});

export const EditUserFactInput = z.object({
  id: Id,
  category: UserFactCategorySchema.optional(),
  value: UserFactValueSchema.optional(),
  spaceIds: UserFactSpaceIds.optional(),
});

export const UpdateUserProfileInput = z.object({
  /** The account name every bot calls the user by. */
  name: z.string().trim().min(1).max(100).optional(),
  timeZone: TimeZoneSchema.nullable().optional(),
  locale: LanguageTagSchema.nullable().optional(),
  language: LanguageTagSchema.nullable().optional(),
  communicationStyle: z.string().trim().max(USER_COMMUNICATION_STYLE_MAX_LENGTH).optional(),
  summary: z.string().trim().max(USER_PROFILE_SUMMARY_MAX_LENGTH).optional(),
  addFacts: z.array(NewUserFactInput).max(50).optional(),
  editFacts: z.array(EditUserFactInput).max(50).optional(),
  /** Pending facts the user agrees bots may use. */
  confirmFactIds: z.array(Id).max(500).optional(),
});
export type UpdateUserProfile = z.infer<typeof UpdateUserProfileInput>;

/** Hard-deletes facts by id, by category, or all of them. */
export const ForgetUserFactsInput = z
  .object({
    factIds: z.array(Id).min(1).max(500).optional(),
    category: UserFactCategorySchema.optional(),
    all: z.literal(true).optional(),
  })
  .superRefine((input, ctx) => {
    const targets = [input.factIds !== undefined, input.category !== undefined, input.all === true];
    if (targets.filter(Boolean).length !== 1) {
      ctx.addIssue({
        code: "custom",
        message: "Provide exactly one of factIds, category, or all",
        path: ["factIds"],
      });
    }
  });
export type ForgetUserFacts = z.infer<typeof ForgetUserFactsInput>;