'use client'

// IdeaMdEditor — bewerk grill_md of plan_md.
//
// - kind='grill': geen yaml-validatie (vrije markdown).
// - kind='plan' : preflight via parsePlanMd (server-side action herhaalt
//   validation, dit is alleen UX om eerder te falen).
//
// Save → updateGrillMdAction / updatePlanMdAction. Cmd/Ctrl+S triggert save.
// LocalStorage-backed draft per idea+kind, restore bij heropening.

import { useEffect, useMemo, useState, useTransition } from 'react'
import { useRouter } from 'next/navigation'
import { Save, X } from 'lucide-react'
import { toast } from 'sonner'

import { Button } from '@/components/ui/button'
import { Textarea } from '@/components/ui/textarea'
import { parsePlanMd, type PlanParseError } from '@/lib/idea-plan-parser'
import { updateGrillMdAction, updatePlanMdAction } from '@/actions/ideas'

type Kind = 'grill' | 'plan'

interface Props {
  ideaId: string
  kind: Kind
  initialValue: string
  onCancel: () => void
}

// Lazily compute the seed: read draft from localStorage on first render, fall
// back to initialValue. Avoids setState-in-useEffect for hydration.
function readSeed(draftKey: string, initialValue: string): {
  value: string
  restored: boolean
} {
  if (typeof window === 'undefined') return { value: initialValue, restored: false }
  const draft = window.localStorage.getItem(draftKey)
  if (draft && draft !== initialValue) return { value: draft, restored: true }
  return { value: initialValue, restored: false }
}

export function IdeaMdEditor({ ideaId, kind, initialValue, onCancel }: Props) {
  const router = useRouter()
  const draftKey = `idea-md-draft-${ideaId}-${kind}`
  const [seed] = useState(() => readSeed(draftKey, initialValue))
  const [value, setValue] = useState(seed.value)
  const [submitErrors, setSubmitErrors] = useState<PlanParseError[]>([])
  const [submitting, startSubmit] = useTransition()

  // Eenmalige toast voor restore — de seed is al toegepast bij mount.
  useEffect(() => {
    if (seed.restored) {
      toast.info('Niet-opgeslagen wijziging hersteld uit lokale draft.')
    }
  }, [seed.restored])

  // Auto-save naar localStorage on change.
  useEffect(() => {
    if (typeof window === 'undefined') return
    if (value === initialValue) {
      window.localStorage.removeItem(draftKey)
    } else {
      window.localStorage.setItem(draftKey, value)
    }
  }, [value, initialValue, draftKey])

  // Live yaml-validatie als afgeleide state — geen useEffect nodig.
  const validationErrors = useMemo<PlanParseError[]>(() => {
    if (kind !== 'plan') return []
    if (value === '' || value === initialValue) return []
    const r = parsePlanMd(value)
    return r.ok ? [] : r.errors
  }, [value, initialValue, kind])

  // Combine: validation errors voor live feedback, submitErrors voor server-side details.
  const errors = submitErrors.length > 0 ? submitErrors : validationErrors

  function save() {
    if (errors.length > 0 && kind === 'plan') {
      toast.error('Frontmatter heeft fouten — fix die eerst.')
      return
    }
    setSubmitErrors([])
    startSubmit(async () => {
      const r =
        kind === 'grill'
          ? await updateGrillMdAction(ideaId, value)
          : await updatePlanMdAction(ideaId, value)
      if ('error' in r) {
        toast.error(r.error)
        if ('details' in r && Array.isArray(r.details)) {
          setSubmitErrors(r.details as PlanParseError[])
        }
        return
      }
      toast.success('Opgeslagen')
      window.localStorage.removeItem(draftKey)
      router.refresh()
      onCancel()
    })
  }

  // Cmd/Ctrl+S → save
  function onKeyDown(e: React.KeyboardEvent<HTMLTextAreaElement>) {
    if ((e.metaKey || e.ctrlKey) && e.key.toLowerCase() === 's') {
      e.preventDefault()
      save()
    }
  }

  const dirty = value !== initialValue

  return (
    <div className="space-y-3">
      {errors.length > 0 && (
        <div className="rounded-md border border-status-blocked/30 bg-status-blocked/10 p-3 space-y-1">
          <p className="text-xs font-medium text-status-blocked">
            {kind === 'plan' ? 'YAML-frontmatter fouten' : 'Validatiefouten'}
          </p>
          <ul className="text-xs text-status-blocked space-y-0.5">
            {errors.map((err, i) => (
              <li key={i}>
                {err.line ? `Regel ${err.line}: ` : ''}
                {err.message}
                {err.hint && (
                  <div className="mt-1 text-foreground/80">Tip: {err.hint}</div>
                )}
              </li>
            ))}
          </ul>
        </div>
      )}

      <Textarea
        value={value}
        onChange={(e) => setValue(e.target.value)}
        onKeyDown={onKeyDown}
        rows={24}
        className="font-mono text-sm leading-relaxed"
        placeholder={
          kind === 'grill'
            ? '# Idee — ...\n## Scope\n...'
            : '---\npbi:\n  title: ...\n  priority: 2\nstories:\n  - title: ...\n---\n\n# Overwegingen\n...'
        }
        disabled={submitting}
      />

      <div className="flex items-center justify-between">
        <p className="text-xs text-muted-foreground">
          {dirty ? 'Niet-opgeslagen wijzigingen — Cmd/Ctrl+S om op te slaan' : 'Geen wijzigingen'}
        </p>
        <div className="flex gap-2">
          <Button variant="outline" size="sm" onClick={onCancel} disabled={submitting}>
            <X className="size-3.5 mr-1" />
            Annuleer
          </Button>
          <Button
            size="sm"
            onClick={save}
            disabled={!dirty || submitting || (errors.length > 0 && kind === 'plan')}
          >
            <Save className="size-3.5 mr-1" />
            Opslaan
          </Button>
        </div>
      </div>
    </div>
  )
}
