frontend/src/lib/personaWizardInitialState.ts

import { loadPersonaDraft } from './drafts'
import { getPersonaById } from './creations'
import { normalizePersonaFormRecord } from './personaFormModel'
import { isPersonaFormFieldKey, PERSONA_FIELD_STEP } from './personaWizardFieldStep'

const STEPNAMES = ['You & the advisor', 'Creativity & expertise', 'Voice & guidelines', 'Review']

export type PersonaWizardSnapshot = {
  editingId: string | null
  data: Record<string, string>
  step: number
}

/** Read draft + URL in one place so useState(initializer) matches the load effect (avoids empty save wiping localStorage). */
export function readPersonaWizardState(searchParams: URLSearchParams): PersonaWizardSnapshot {
  const focusRaw = searchParams.get('focus')
  const focusKey = focusRaw && isPersonaFormFieldKey(focusRaw) ? focusRaw : null
  const stepFromFocus = focusKey != null ? PERSONA_FIELD_STEP[focusKey] : null

  const stepParam = searchParams.get('step')
  let parsedStep: number | null = null
  if (stepParam != null) {
    const n = Number.parseInt(stepParam, 10)
    if (!Number.isNaN(n) && n >= 0 && n < STEPNAMES.length) parsedStep = n
  }

  const edit = searchParams.get('edit')
  if (edit) {
    const p = getPersonaById(edit)
    if (p) {
      const normalized = normalizePersonaFormRecord(p as unknown as Record<string, unknown>)
      let step = 0
      if (stepFromFocus != null) step = stepFromFocus
      else if (parsedStep != null) step = parsedStep
      return {
        editingId: edit,
        data: normalized,
        step,
      }
    }
  }
  const d = loadPersonaDraft() as Record<string, unknown>
  let step = 0
  const ws = d._wizardStep
  if (typeof ws === 'number' && ws >= 0 && ws < STEPNAMES.length) step = ws
  if (stepFromFocus != null) step = stepFromFocus
  else if (parsedStep != null) step = parsedStep
  const normalized = normalizePersonaFormRecord(d)

  const savedId = typeof d._editingId === 'string' && d._editingId ? d._editingId : null
  const editingId = savedId && getPersonaById(savedId) ? savedId : null

  return {
    editingId,
    data: normalized,
    step,
  }
}