export const INCIDENT_TYPES = ['injury', 'near_miss', 'hazard', 'asset_damage', 'environmental', 'security', 'fire', 'transport'] as const
export const MEDICAL_STATUSES = ['none', 'first_aid', 'medical_treatment', 'lti'] as const

export type IncidentType = typeof INCIDENT_TYPES[number]
export type MedicalStatus = typeof MEDICAL_STATUSES[number]

export interface IncidentInput {
  zone_token: string
  incident_type: IncidentType
  description: string
  injury_involved: boolean
  medical_status?: MedicalStatus
  asset_involved: boolean
  type_details?: Record<string, unknown>
  truck_id?: string | null
}

// Whitelisted type-specific intake fields per incident type (PRD §3).
// 's' = free text, 'b' = boolean. Near miss / hazard / injury stay minimal by design.
export const TYPE_DETAIL_FIELDS: Partial<Record<IncidentType, Record<string, 's' | 'b'>>> = {
  environmental: { substance: 's', estimated_volume: 's', containment_deployed: 'b' },
  asset_damage: { equipment_id: 's', loto_applied: 'b' },
  security: { persons_involved: 's', police_reported: 'b' },
  fire: { alarm_raised: 'b', fire_brigade_called: 'b' },
}

export function validateTypeDetails(
  incidentType: IncidentType,
  details: Record<string, unknown> | undefined,
): { ok: boolean; errors: string[]; sanitized: Record<string, unknown> | null } {
  if (details == null || Object.keys(details).length === 0) {
    return { ok: true, errors: [], sanitized: null }
  }

  const allowed = TYPE_DETAIL_FIELDS[incidentType]
  if (!allowed) {
    return { ok: false, errors: [`type_details not allowed for incident_type ${incidentType}`], sanitized: null }
  }

  const errors: string[] = []
  const sanitized: Record<string, unknown> = {}

  for (const [key, value] of Object.entries(details)) {
    const kind = allowed[key]
    if (!kind) {
      errors.push(`unknown type_details field: ${key}`)
      continue
    }
    if (kind === 's') {
      if (typeof value !== 'string') {
        errors.push(`${key} must be a string`)
        continue
      }
      const trimmed = value.trim()
      if (trimmed) sanitized[key] = trimmed.slice(0, 500)
    } else {
      if (typeof value !== 'boolean') {
        errors.push(`${key} must be a boolean`)
        continue
      }
      sanitized[key] = value
    }
  }

  return {
    ok: errors.length === 0,
    errors,
    sanitized: Object.keys(sanitized).length > 0 ? sanitized : null,
  }
}

export function validateIncidentInput(input: IncidentInput): { ok: boolean; errors: string[] } {
  const errors: string[] = []

  if (!input.zone_token?.trim()) errors.push('zone_token is required')
  if (input.description.trim().length < 10) errors.push('description must be at least 10 characters')
  if (!INCIDENT_TYPES.includes(input.incident_type)) errors.push('incident_type is invalid')
  if (input.injury_involved && !input.medical_status) errors.push('medical_status is required when injury is involved')
  if (input.medical_status && !MEDICAL_STATUSES.includes(input.medical_status)) errors.push('medical_status is invalid')
  if (input.incident_type === 'transport' && !input.truck_id?.trim())
    errors.push('truck_id is required for transport incidents')

  return { ok: errors.length === 0, errors }
}