import { ref, readonly } from 'vue'
import type { AlbionPriceEntry, AlbionCity, ManualPriceEntry, ManualPriceCache } from '../types/api'

// ─── Override duration ────────────────────────────────────────────────────────

export const OVERRIDE_DURATION_OPTIONS: { label: string; ms: number }[] = [
  { label: '30 min',  ms: 30 * 60 * 1000 },
  { label: '1 hour',  ms: 60 * 60 * 1000 },
  { label: '2 hours', ms: 2 * 60 * 60 * 1000 },
  { label: '4 hours', ms: 4 * 60 * 60 * 1000 },
  { label: '8 hours', ms: 8 * 60 * 60 * 1000 },
  { label: '24 hours',ms: 24 * 60 * 60 * 1000 },
]

const DURATION_STORAGE_KEY = 'albion-override-duration'
const MANUAL_STORAGE_KEY   = 'albion-manual-prices'

function loadOverrideDuration(): number {
  try {
    const raw = localStorage.getItem(DURATION_STORAGE_KEY)
    if (raw) {
      const ms = Number(raw)
      if (OVERRIDE_DURATION_OPTIONS.some(o => o.ms === ms)) return ms
    }
  } catch { /* ignore */ }
  return 24 * 60 * 60 * 1000 // default 24 hours
}

function loadManualPricesFromStorage(): ManualPriceCache {
  try {
    const raw = localStorage.getItem(MANUAL_STORAGE_KEY)
    if (raw) {
      const obj = JSON.parse(raw) as Record<string, ManualPriceEntry>
      return new Map(Object.entries(obj))
    }
  } catch { /* ignore */ }
  return new Map()
}

function saveManualPricesToStorage(map: ManualPriceCache): void {
  try {
    const obj: Record<string, ManualPriceEntry> = {}
    for (const [key, val] of map) obj[key] = val
    localStorage.setItem(MANUAL_STORAGE_KEY, JSON.stringify(obj))
  } catch { /* ignore */ }
}

// ─── Module-level singleton state ────────────────────────────────────────────

const manualPrices     = ref<ManualPriceCache>(loadManualPricesFromStorage())
const overrideDurationMs = ref<number>(loadOverrideDuration())

// ─── Helpers ──────────────────────────────────────────────────────────────────

function cacheKey(itemId: string, city: string): string {
  return `${itemId}::${city}`
}

function isManualExpired(entry: ManualPriceEntry): boolean {
  return Date.now() - new Date(entry.editedAt).getTime() > overrideDurationMs.value
}

function synthesizeManualEntry(
  entry: ManualPriceEntry,
  itemId: string,
  city: AlbionCity,
): AlbionPriceEntry {
  return {
    item_id: itemId,
    city,
    quality: 1,
    sell_price_min: entry.sell_price_min,
    sell_price_min_date: entry.editedAt,
    sell_price_max: entry.sell_price_min,
    buy_price_min: 0,
    buy_price_max: 0,
  }
}

// ─── Price accessors ──────────────────────────────────────────────────────────

function getPrice(itemId: string, city: AlbionCity): AlbionPriceEntry | null {
  const key = cacheKey(itemId, city)
  const manual = manualPrices.value.get(key)
  if (manual && !isManualExpired(manual)) {
    return synthesizeManualEntry(manual, itemId, city)
  }
  return null
}

// ─── Manual price management ──────────────────────────────────────────────────

function setManualPrice(itemId: string, city: AlbionCity, price: number): void {
  const key = cacheKey(itemId, city)
  const next = new Map(manualPrices.value)
  next.set(key, { sell_price_min: price, editedAt: new Date().toISOString() })
  manualPrices.value = next
  saveManualPricesToStorage(next)
}

function clearManualPrice(itemId: string, city: AlbionCity): void {
  const key = cacheKey(itemId, city)
  if (!manualPrices.value.has(key)) return
  const next = new Map(manualPrices.value)
  next.delete(key)
  manualPrices.value = next
  saveManualPricesToStorage(next)
}

function isManualPrice(itemId: string, city: AlbionCity): boolean {
  const entry = manualPrices.value.get(cacheKey(itemId, city))
  return !!entry && !isManualExpired(entry)
}

function getManualEntry(itemId: string, city: AlbionCity): ManualPriceEntry | undefined {
  const entry = manualPrices.value.get(cacheKey(itemId, city))
  return entry && !isManualExpired(entry) ? entry : undefined
}

function setOverrideDuration(ms: number): void {
  overrideDurationMs.value = ms
  try { localStorage.setItem(DURATION_STORAGE_KEY, String(ms)) } catch { /* ignore */ }
}

// ─── Public API ───────────────────────────────────────────────────────────────

export function useAlbionPrices() {
  return {
    overrideDurationMs: readonly(overrideDurationMs),
    getPrice,
    setManualPrice,
    clearManualPrice,
    isManualPrice,
    getManualEntry,
    setOverrideDuration,
  }
}