/**
 * Hand-rolled runtime validators for IPC payloads.
 *
 * TypeScript types are erased at compile time — a compromised or buggy
 * renderer can still send arbitrary JSON across the IPC boundary. These
 * helpers enforce shape, type and range BEFORE the data hits the store.
 *
 * Philosophy: be lenient with unknown fields (drop them silently), strict
 * about known fields (reject the call if a known field is the wrong type
 * or out of range). Never throw to the renderer; return a sanitised value
 * or `null` and the caller decides what to do.
 */

import type {
  Challenge,
  Exercise,
  GameStat,
  Settings,
  Theme,
  Language,
  NotificationMode
} from '@shared/types'

const MAX_STR_LEN = 200
const VALID_THEMES: Theme[] = ['system', 'light', 'dark']
const VALID_LANGS: Language[] = ['ru', 'en']
const VALID_NOTIFY: NotificationMode[] = ['toast', 'modal', 'both']
const VALID_STATS: GameStat[] = [
  'deaths',
  'kills',
  'assists',
  'last_hits',
  'denies',
  'duration_min'
]
const HHMM_RE = /^\d{1,2}:\d{2}$/

function isObj(v: unknown): v is Record<string, unknown> {
  return typeof v === 'object' && v !== null && !Array.isArray(v)
}

function safeStr(v: unknown, max = MAX_STR_LEN): string | undefined {
  if (typeof v !== 'string') return undefined
  if (v.length === 0 || v.length > max) return undefined
  return v
}

function intInRange(v: unknown, min: number, max: number): number | undefined {
  if (typeof v !== 'number' || !Number.isFinite(v)) return undefined
  const n = Math.trunc(v)
  if (n < min || n > max) return undefined
  return n
}

function numInRange(v: unknown, min: number, max: number): number | undefined {
  if (typeof v !== 'number' || !Number.isFinite(v)) return undefined
  if (v < min || v > max) return undefined
  return v
}

function bool(v: unknown): boolean | undefined {
  return typeof v === 'boolean' ? v : undefined
}

function oneOf<T extends string>(
  v: unknown,
  allowed: readonly T[]
): T | undefined {
  return typeof v === 'string' && (allowed as readonly string[]).includes(v)
    ? (v as T)
    : undefined
}

// -----------------------------------------------------------------------
// Exercise validators
// -----------------------------------------------------------------------

export function validateExerciseInput(
  raw: unknown
): Omit<Exercise, 'id' | 'nextFireAt' | 'lastDoneAt'> | null {
  if (!isObj(raw)) return null
  const name = safeStr(raw.name)
  const reps = intInRange(raw.reps, 1, 9999)
  const intervalMinutes = intInRange(raw.intervalMinutes, 1, 24 * 60)
  const icon = safeStr(raw.icon, 64) ?? 'Activity'
  const enabled = bool(raw.enabled) ?? true
  if (
    name === undefined ||
    reps === undefined ||
    intervalMinutes === undefined
  ) {
    return null
  }
  return { name, reps, intervalMinutes, icon, enabled }
}

export function validateExercisePatch(
  raw: unknown
): Partial<Omit<Exercise, 'id'>> | null {
  if (!isObj(raw)) return null
  const out: Partial<Omit<Exercise, 'id'>> = {}
  if ('name' in raw) {
    const v = safeStr(raw.name)
    if (v === undefined) return null
    out.name = v
  }
  if ('reps' in raw) {
    const v = intInRange(raw.reps, 1, 9999)
    if (v === undefined) return null
    out.reps = v
  }
  if ('intervalMinutes' in raw) {
    const v = intInRange(raw.intervalMinutes, 1, 24 * 60)
    if (v === undefined) return null
    out.intervalMinutes = v
  }
  if ('icon' in raw) {
    const v = safeStr(raw.icon, 64)
    if (v === undefined) return null
    out.icon = v
  }
  if ('enabled' in raw) {
    const v = bool(raw.enabled)
    if (v === undefined) return null
    out.enabled = v
  }
  // Allow scheduler-controlled fields to be patched (used by store.markDone
  // through this same boundary), but range-check them.
  if ('nextFireAt' in raw) {
    const v = numInRange(raw.nextFireAt, 0, Number.MAX_SAFE_INTEGER)
    if (v === undefined) return null
    out.nextFireAt = v
  }
  if ('lastDoneAt' in raw) {
    const v = numInRange(raw.lastDoneAt, 0, Number.MAX_SAFE_INTEGER)
    if (v === undefined) return null
    out.lastDoneAt = v
  }
  return out
}

// -----------------------------------------------------------------------
// Challenge validators
// -----------------------------------------------------------------------

export function validateChallengeInput(
  raw: unknown
): Omit<Challenge, 'id'> | null {
  if (!isObj(raw)) return null
  const name = safeStr(raw.name)
  const gameId = safeStr(raw.gameId, 32)
  const stat = oneOf(raw.stat, VALID_STATS)
  const multiplier = numInRange(raw.multiplier, 0, 1000)
  const exerciseName = safeStr(raw.exerciseName)
  const icon = safeStr(raw.icon, 64) ?? 'Activity'
  const enabled = bool(raw.enabled) ?? true
  if (
    name === undefined ||
    gameId === undefined ||
    stat === undefined ||
    multiplier === undefined ||
    exerciseName === undefined
  ) {
    return null
  }
  return {
    name,
    gameId: gameId as Challenge['gameId'],
    stat,
    multiplier,
    exerciseName,
    icon,
    enabled
  }
}

export function validateChallengePatch(
  raw: unknown
): Partial<Omit<Challenge, 'id'>> | null {
  if (!isObj(raw)) return null
  const out: Partial<Omit<Challenge, 'id'>> = {}
  if ('name' in raw) {
    const v = safeStr(raw.name)
    if (v === undefined) return null
    out.name = v
  }
  if ('exerciseName' in raw) {
    const v = safeStr(raw.exerciseName)
    if (v === undefined) return null
    out.exerciseName = v
  }
  if ('stat' in raw) {
    const v = oneOf(raw.stat, VALID_STATS)
    if (v === undefined) return null
    out.stat = v
  }
  if ('multiplier' in raw) {
    const v = numInRange(raw.multiplier, 0, 1000)
    if (v === undefined) return null
    out.multiplier = v
  }
  if ('icon' in raw) {
    const v = safeStr(raw.icon, 64)
    if (v === undefined) return null
    out.icon = v
  }
  if ('enabled' in raw) {
    const v = bool(raw.enabled)
    if (v === undefined) return null
    out.enabled = v
  }
  return out
}

// -----------------------------------------------------------------------
// Settings validators
// -----------------------------------------------------------------------

export function validateSettingsPatch(raw: unknown): Partial<Settings> | null {
  if (!isObj(raw)) return null
  const out: Partial<Settings> = {}
  if ('globalEnabled' in raw) {
    const v = bool(raw.globalEnabled)
    if (v === undefined) return null
    out.globalEnabled = v
  }
  if ('startWithWindows' in raw) {
    const v = bool(raw.startWithWindows)
    if (v === undefined) return null
    out.startWithWindows = v
  }
  if ('startMinimized' in raw) {
    const v = bool(raw.startMinimized)
    if (v === undefined) return null
    out.startMinimized = v
  }
  if ('minimizeToTray' in raw) {
    const v = bool(raw.minimizeToTray)
    if (v === undefined) return null
    out.minimizeToTray = v
  }
  if ('soundEnabled' in raw) {
    const v = bool(raw.soundEnabled)
    if (v === undefined) return null
    out.soundEnabled = v
  }
  if ('voicePromptsEnabled' in raw) {
    const v = bool(raw.voicePromptsEnabled)
    if (v === undefined) return null
    out.voicePromptsEnabled = v
  }
  if ('notificationMode' in raw) {
    const v = oneOf(raw.notificationMode, VALID_NOTIFY)
    if (v === undefined) return null
    out.notificationMode = v
  }
  if ('theme' in raw) {
    const v = oneOf(raw.theme, VALID_THEMES)
    if (v === undefined) return null
    out.theme = v
  }
  if ('language' in raw) {
    const v = oneOf(raw.language, VALID_LANGS)
    if (v === undefined) return null
    out.language = v
  }
  if ('snoozeMinutes' in raw) {
    const v = intInRange(raw.snoozeMinutes, 1, 24 * 60)
    if (v === undefined) return null
    out.snoozeMinutes = v
  }
  if ('quietHours' in raw) {
    const qh = raw.quietHours
    if (!isObj(qh)) return null
    const enabled = bool(qh.enabled)
    const from = safeStr(qh.from, 8)
    const to = safeStr(qh.to, 8)
    if (
      enabled === undefined ||
      from === undefined ||
      to === undefined ||
      !HHMM_RE.test(from) ||
      !HHMM_RE.test(to)
    ) {
      return null
    }
    if (!Array.isArray(qh.days)) return null
    const days: number[] = []
    for (const d of qh.days) {
      const n = intInRange(d, 0, 6)
      if (n === undefined) return null
      if (!days.includes(n)) days.push(n)
    }
    out.quietHours = { enabled, from, to, days }
  }
  return out
}

// -----------------------------------------------------------------------
// Misc tiny validators
// -----------------------------------------------------------------------

export function validateId(raw: unknown): string | null {
  // UUIDs from store.ts via randomUUID(); accept any reasonable string id.
  const v = safeStr(raw, 64)
  return v ?? null
}

export function validateActualReps(raw: unknown): number | undefined {
  if (raw === undefined || raw === null) return undefined
  return intInRange(raw, 0, 100000) ?? undefined
}

export function validateSnoozeMinutes(raw: unknown): number | null {
  return intInRange(raw, 1, 24 * 60) ?? null
}