import { tryParseJSON } from '@opentf/std';

tryParseJSON<T>(text: unknown, fallback?: T, reviverOrOptions?: ((key: string, value: unknown) => unknown) | { reviver?: (key: string, value: unknown) => unknown, temporal?: boolean }): T | undefined

tryParseJSON('{"a":1}') //=> {a:1}
tryParseJSON('[1,2,3]') //=> [1,2,3]
tryParseJSON('null') //=> null
tryParseJSON('"hi"') //=> "hi"

// Invalid JSON → fallback, not throw
tryParseJSON('bad') //=> undefined
tryParseJSON('bad', { a: 1 }) //=> {a:1}
tryParseJSON('{a:1}', 42) //=> 42 — unquoted keys
tryParseJSON('', 'fallback') //=> "fallback"

// Non-string input → fallback (e.g. missing localStorage key)
tryParseJSON(null as any, []) //=> []
tryParseJSON(undefined as any) //=> undefined
tryParseJSON(123 as any, {}) //=> {}

// localStorage pattern — the #1 use case
const cached = tryParseJSON(localStorage.getItem("prefs"), { theme: "light" });
 // getItem returns string | null — null → fallback, bad JSON → fallback

// fetch + json
const data = tryParseJSON(await res.text(), null);
// vs try { await res.json() } catch { null } — same but typed

// Generic is preserved
type User = { id: string; name: string };
const user = tryParseJSON<User>('{"id":"1","name":"Ana"}');
//    ^? User | undefined

const safeUser = tryParseJSON<User>('bad', { id: "0", name: "Guest" });
//    ^? User — fallback guarantees T

// Reviver — e.g. revive dates (legacy)
const reviver = (k: string, v: unknown) =>
  k === "createdAt" && typeof v === "string" ? new Date(v as string) : v;

tryParseJSON('{"createdAt":"2024-01-01T00:00:00.000Z"}', undefined, reviver)
//=> { createdAt: Date }

// Options form — reviver + temporal
tryParseJSON('{"a":1}', undefined, { reviver })
// same as above

// Temporal — default true (like bigint stringify)
// Date already works via toJSON, this is for DateTime/Duration/Temporal
tryParseJSON('{"t":"2024-01-01T00:00:00.000Z"}')
//=> { t: DateTime } — ISO datetime → DateTime by default

tryParseJSON('{"d":"P1DT2H"}')
//=> { d: Duration } — ISO duration → Duration

tryParseJSON('{"t":"2024-01-01"}', undefined, { temporal: false })
//=> { t: "2024-01-01" } — string when disabled

// Temporal composes with reviver
tryParseJSON('{"n":1}', undefined, {
  reviver: (k, v) => k === "n" && typeof v === "number" ? v * 10 : v
}) //=> { n: 10 } — temporal default still revives dates alongside

// Native Temporal (where runtime has Temporal) also revives with default
// {"t":"2024-01-01T00:00:00Z"} → Temporal.Instant when Temporal available
tryParseJSON('{"t":"2024-01-01T00:00:00Z"}') //=> {t: Temporal.Instant} on Temporal runtimes

// Compare with isJSON — check first vs parse with fallback
import { isJSON } from '@opentf/std';
isJSON('{"a":1}') //=> true — tells you it parses, but not the value
tryParseJSON('{"a":1}') //=> {a:1} — tells you and gives the value