// Pure task-engine model (spec §3–§4): the task types and the duration formula. No lib/db
// imports — the frontend imports this for the live duration preview in the crew picker
// (same precedent as tech.ts / ship-costs.ts).
import { MISMATCH_CANCEL_TRAIT, PREFERRED_ROLES, TRAIT_DURATION_MODIFIERS, WORK_POINTS } from './crew-costs'
import type { CrewMember } from './crew'

export type TaskType = 'JUMP' | 'EXPLORE' | 'SHIP_UPGRADE' | 'SHIP_EXPAND' | 'SHIP_BUILD' | 'RESEARCH'

// Work points per action (spec §4): JUMP scales with hop count, the rest are flat.
function workPoints(type: TaskType, hopCount: number): number {
  switch (type) {
    case 'JUMP':
      return hopCount * WORK_POINTS.JUMP_PER_HOP
    case 'EXPLORE':
      return WORK_POINTS.EXPLORE
    case 'RESEARCH':
      return WORK_POINTS.RESEARCH
    default:
      return WORK_POINTS.SHIP_WORK // SHIP_UPGRADE | SHIP_EXPAND | SHIP_BUILD
  }
}

// One trait's modifier for a lead on an action type: its per-type entry plus the 'ANY' entry.
// Traits without a map entry contribute 0.
function traitModifier(trait: string, type: TaskType): number {
  const mods = TRAIT_DURATION_MODIFIERS[trait]
  if (!mods) return 0
  return (mods[type] ?? 0) + (mods['ANY'] ?? 0)
}

// duration = max(1, ceil(work / totalPower) + mismatchPenalty + traitModifierSum) — spec §4.
// totalPower = Σ powerOf over the WHOLE team (lead + helpers); the default powerOf is the
// constant 1 until PR B feeds the skill band. The mismatch penalty and the trait modifiers
// apply to the LEAD only — helpers contribute power, are never penalised, and their traits do
// not apply. `hopCount` is only meaningful for JUMP (pass 1 for the other types).
export function computeDuration(
  type: TaskType,
  hopCount: number,
  lead: CrewMember,
  helpers: CrewMember[],
  powerOf: (m: CrewMember) => number = () => 1,
): number {
  const totalPower = Math.max(1, [lead, ...helpers].reduce((sum, m) => sum + powerOf(m), 0))
  const mismatchPenalty = lead.traitGood === MISMATCH_CANCEL_TRAIT || PREFERRED_ROLES[type].includes(lead.role) ? 0 : 1
  const traitModifierSum = traitModifier(lead.traitGood, type) + traitModifier(lead.traitBad, type)
  return Math.max(1, Math.ceil(workPoints(type, hopCount) / totalPower) + mismatchPenalty + traitModifierSum)
}