// Predefined distances from 4550 Asnæs to major postal codes (round trip in km)
// This is a simplified approach for MVP - can be replaced with actual API later
export const POSTAL_CODE_DISTANCES: Record<string, number> = {
  // København (2000-2999)
  "2000": 200, // København K
  "2100": 206, // København Ø
  "2200": 208, // København N
  "2300": 200, // København S
  "2400": 210, // København NV
  "2450": 216, // København SV
  "2500": 194, // Valby
  "2600": 182, // Glostrup
  "2700": 188, // Brønshøj
  "2800": 162, // Lyngby
  "2900": 154, // Hellerup

  // Nordsjælland (3000-3999)
  "3000": 138, // Helsingør
  "3050": 132, // Humlebæk
  "3100": 128, // Hornbæk
  "3200": 110, // Helsinge
  "3300": 92, // Frederiksværk
  "3400": 112, // Hillerød
  "3460": 144, // Birkerød
  "3500": 116, // Værløse
  "3600": 90, // Frederikssund

  // Vestsjælland (4000-4999)
  "4000": 66, // Roskilde
  "4100": 56, // Ringsted
  "4200": 86, // Slagelse
  "4300": 32, // Holbæk
  "4400": 20, // Kalundborg
  "4500": 16, // Nykøbing Sjælland
  "4550": 0, // Asnæs (hjemmebase)
  "4600": 70, // Køge
  "4700": 132, // Næstved
  "4800": 216, // Nykøbing F
  "4900": 256, // Nakskov

  // Fyn (5000-5999)
  "5000": 290, // Odense C
  "5100": 330, // Odense C
  "5200": 300, // Odense V
  "5220": 296, // Odense SØ
  "5250": 284, // Odense SV
  "5260": 288, // Odense S
  "5270": 292, // Odense N
  "5500": 350, // Middelfart
  "5600": 360, // Faaborg
  "5700": 340, // Svendborg
  "5800": 380, // Nyborg
  "5900": 370, // Rudkøbing
}

// Default distances based on first two digits of postal code
const DEFAULT_DISTANCES: Record<string, number> = {
  "20": 200, // København området
  "21": 206,
  "22": 208,
  "23": 200,
  "24": 210,
  "25": 194,
  "26": 182,
  "27": 188,
  "28": 162,
  "29": 154,
  "30": 138, // Nordsjælland
  "31": 128,
  "32": 110,
  "33": 92,
  "34": 112,
  "35": 116,
  "36": 90,
  "40": 66, // Vestsjælland
  "41": 56,
  "42": 86,
  "43": 32,
  "44": 20,
  "45": 16,
  "46": 70,
  "47": 132,
  "48": 216, // Lolland-Falster
  "49": 256,
  "50": 290, // Fyn
  "51": 330,
  "52": 296,
  "53": 310,
  "54": 320,
  "55": 350,
  "56": 360,
  "57": 340,
  "58": 380,
  "59": 370,
}

export function getDistance(postalCode: string): number {
  // First check if we have an exact match
  if (POSTAL_CODE_DISTANCES[postalCode]) {
    return POSTAL_CODE_DISTANCES[postalCode]
  }

  // Otherwise use default based on first two digits
  const prefix = postalCode.slice(0, 2)
  if (DEFAULT_DISTANCES[prefix]) {
    return DEFAULT_DISTANCES[prefix]
  }

  // If still no match, estimate based on region
  const firstDigit = postalCode[0]
  switch (firstDigit) {
    case "2":
      return 190 // København average
    case "3":
      return 110 // Nordsjælland average
    case "4":
      return 100 // Vestsjælland average
    case "5":
      return 320 // Fyn average
    default:
      return 200 // Default fallback
  }
}

export function isInCoverageArea(postalCode: string): boolean {
  const firstDigit = postalCode[0]
  const postalNumber = parseInt(postalCode)

  // Check main coverage areas
  if (["2", "3", "4", "5"].includes(firstDigit)) {
    // Special check for Lolland-Falster (4800-4899)
    if (postalNumber >= 4800 && postalNumber <= 4899) {
      return true
    }
    // Exclude other 4900+ areas
    if (postalNumber >= 4900 && postalNumber < 5000) {
      return false
    }
    return true
  }

  return false
}

export function validateDanishPostalCode(postalCode: string): boolean {
  // Danish postal codes are 4 digits
  if (!/^\d{4}$/.test(postalCode)) {
    return false
  }

  // Valid ranges for Danish postal codes
  const code = parseInt(postalCode)
  return code >= 1000 && code <= 9999
}