// Pure ship-system model: the known system types, base values and the action cost model.
// No DB imports — both lib/game/ship.ts (server) and the frontend import from here so the
// UI's affordability/cap logic can never drift from what the API enforces.

export interface ShipTypeDef {
  type: string
  builtAtStart: boolean // part of the starting ship? (otherwise unbuilt until BUILD)
}

// The known system types — display order. Reuses the placeholder SHIP SYSTEMS tab card names
// for continuity, plus HULL so the vessel-metrics hull bar can be driven by a real level.
export const SHIP_TYPES: ShipTypeDef[] = [
  { type: 'HULL', builtAtStart: true },
  { type: 'REACTOR', builtAtStart: true },
  { type: 'LIFE SUPPORT', builtAtStart: true },
  { type: 'NAV COMPUTER', builtAtStart: true },
  { type: 'COMMS ARRAY', builtAtStart: true },
  { type: 'WEAPONS', builtAtStart: false },
]

export const BASE_LEVEL = 1 // what a system starts at when built (starting ship or BUILD)
export const BASE_CAPACITY = 2
export const MAX_LEVEL = 5 // UPGRADE cap
export const MAX_CAPACITY = 10 // EXPAND cap

// Display-only cap for the VESSEL METRICS crew roster bar (no gameplay effect yet).
export const CREW_CAPACITY = 6

// Cost model — all costs are in inventory items, consumed from the oldest cargo row of the
// required kind first (see spendItems in lib/game/ship.ts):
//   UPGRADE {systemId} — `level` units of any resource (scales with current level)
//   EXPAND  {systemId} — `capacity` units of any resource (scales with current capacity)
//   BUILD   {type}     — a flat amount of parts (parts are rarer than resources, so builds
//                        are the bigger investment)
export function upgradeCost(level: number): number {
  return level
}

export function expandCost(capacity: number): number {
  return capacity
}

export const BUILD_PART_COST = 3

// Total qty of one kind across the cargo hold — used for affordability checks.
export function totalQty(items: { kind: string; qty: number }[], kind: 'resource' | 'part'): number {
  return items.filter((i) => i.kind === kind).reduce((sum, i) => sum + i.qty, 0)
}