// Turns an everyday instruction (English or Indonesian) into schedule rules, e.g.
// "make 2 summaries per day and 1 quiz per week about leadership, research the internet daily about sales"
// "bikin 2 summary per hari dan 1 kuis per minggu soal leadership, riset internet tiap hari soal sales".
// Deterministic on purpose: the user always sees and can correct the result before anything is created.
import { t, type Key } from '../i18n'

export type ContentKind = 'summary' | 'quiz' | 'flashcards' | 'roleplay' | 'simulator' | 'slide_deck' | 'video' | 'audio' | 'scorm'

export const KINDS: ContentKind[] = ['summary', 'quiz', 'flashcards', 'roleplay', 'simulator', 'slide_deck', 'video', 'audio', 'scorm']

// Every kind runs on the engine's agents, in one of two ways:
// - recurring content production (content_goal): the six Compose kinds, plus audio (a narration
//   script, played and downloaded in Express) and SCORM (a lesson + quiz pair packaged in Express);
// - one scheduled run per day or week (run_schedule): video, since the engine renders one video per run.
export const SCHEDULABLE: ReadonlySet<ContentKind> = new Set(KINDS)

export const kindLabel = (kind: ContentKind) => t(`kind.${kind}` as Key)

// Checked in order; the first match wins, so multi-word phrases come before their parts.
const KIND_WORDS: [ContentKind, RegExp][] = [
  // SCORM first: a SCORM module includes a quiz, so "SCORM module with a quiz" is still SCORM.
  ['scorm', /\b(scorm|skorm|skong|e-?learning)\b/],
  ['flashcards', /\b(flash ?cards?|kartu (belajar|hafalan))\b/],
  ['quiz', /\b(kuis|quiz|quizzes|soal latihan|tes|tests?|ujian|exams?)\b/],
  ['roleplay', /\b(role ?-?plays?|bermain peran)\b/],
  ['simulator', /\b(simulasi|simulations?|simulators?|skenario|scenarios?)\b/],
  ['slide_deck', /\b(slides?|presentasi|presentations?|decks?|ppt)\b/],
  ['video', /\b(videos?)\b/],
  ['audio', /\b(audio|podcasts?|siniar|narasi|narrations?)\b/],
  ['summary', /\b(summary|summaries|ringkasan|rangkuman|artikel|articles?|teks|texts?)\b/],
]

const NUMBER_WORDS: Record<string, number> = {
  satu: 1, se: 1, sebuah: 1, dua: 2, tiga: 3, empat: 4, lima: 5, enam: 6, tujuh: 7, delapan: 8, sembilan: 9, sepuluh: 10,
  a: 1, an: 1, one: 1, two: 2, three: 3, four: 4, five: 5, six: 6, seven: 7, eight: 8, nine: 9, ten: 10,
}

// Monday = 0, as the engine counts.
const WEEKDAYS: [RegExp, number][] = [
  [/\b(senin|monday)\b/, 0], [/\b(selasa|tuesday)\b/, 1], [/\b(rabu|wednesday)\b/, 2], [/\b(kamis|thursday)\b/, 3],
  [/\b(jum'?at|friday)\b/, 4], [/\b(sabtu|saturday)\b/, 5],
  // "minggu" is both Sunday and "week", so Indonesian Sunday needs "hari minggu".
  [/\b(hari minggu|sunday)\b/, 6],
]

export type Per = 'day' | 'week'

// The output languages the engine writes in (generation_brief.OutputLanguage, AgentVideoOptions.language).
export type OutputLanguage = 'English' | 'Bahasa Indonesia' | '中文'
export const LANGUAGES: OutputLanguage[] = ['Bahasa Indonesia', 'English', '中文']
export const languageLabel = (l: OutputLanguage) => (l === '中文' ? '中文 (Mandarin)' : l)

// "in English", "pakai bahasa Inggris", "dalam bahasa Mandarin". A bare country name needs "bahasa",
// so a topic such as "sales in China" is not read as a language.
const LANGUAGE_CORE = String.raw`bahasa\s+(?:indonesia|indo|inggris|english|mandarin|cina|china|tionghoa)|indonesian|english|inggris|mandarin|chinese|中文`
const LANGUAGE_PHRASE = new RegExp(
  String.raw`(?<!\p{L})(?:(?:in|dalam|pakai|pake|memakai|menggunakan|gunakan|using|use|with|berbahasa)\s+)?(?:the\s+)?(?:${LANGUAGE_CORE})(?:\s+language)?(?!\p{L})`,
  'gu',
)

/** The output language a text names, if any. */
export function languageOf(text: string): OutputLanguage | null {
  const m = text.toLowerCase().match(LANGUAGE_PHRASE)?.[0]
  if (!m) return null
  return /indo/.test(m) ? 'Bahasa Indonesia' : /english|inggris/.test(m) ? 'English' : '中文'
}

export interface ContentRule {
  type: 'content'
  kind: ContentKind
  count: number
  per: Per
  topic: string
  /** The monthly count the instruction asked for, when it had to be turned into a weekly one. */
  monthly?: number
  /** The language the content is written in; unset means the UI language. */
  language?: OutputLanguage
}

export interface ResearchRule {
  type: 'research'
  cadence: 'daily' | 'weekly'
  weekday: number
  topic: string
  autoApprove: boolean
  /** Weekly research whose instruction named no day, so Monday is only a default the agent asks about. */
  weekdayGuessed?: boolean
}

export type Rule = ContentRule | ResearchRule

export interface ParseResult {
  rules: Rule[]
  /** Clauses that said something but matched no rule, so the user can rephrase them. */
  unknown: string[]
  /** The output language the instruction named. */
  language?: OutputLanguage
}

// "dari file LLM" / "from the document onboarding" names a Brain file, which works as the topic.
const TOPIC = /\b(?:soal|tentang|mengenai|seputar|terkait|topik|bertema|perihal|about|regarding|covering|related to|on the topic of|topic|(?:dari|from)(?: the)? (?:file|berkas|dokumen|documents?|materi|material))\s+(?!latihan\b)(.+)$/
const FREQUENCY_TAIL = /\b(tiap|setiap|per|sehari|seminggu|every|each|daily|weekly|monthly|a day|a week|a month)\b.*$/

function topicOf(clause: string): string {
  return clause.match(TOPIC)?.[1].replace(FREQUENCY_TAIL, '').replace(/[\s,]+$/, '').trim() ?? ''
}

function countOf(clause: string, kindAt: number): number {
  const before = clause.slice(0, kindAt)
  const digits = before.match(/(\d+)\s*(?:buah|x|kali|new)?\s*$/)
  // "0" schedules nothing; the preview shows 1, which the user can still change.
  if (digits) return Math.max(1, Number(digits[1]))
  const word = before.match(/(\p{L}+)\s*(?:buah|new)?\s*$/u)?.[1]
  return (word && NUMBER_WORDS[word]) || 1
}

export function perOf(clause: string): Per | 'month' {
  if (/\b(per ?hari|tiap hari|setiap hari|sehari|harian|per day|a day|every day|each day|daily)\b/.test(clause)) return 'day'
  if (/\b(per ?bulan|tiap bulan|setiap bulan|sebulan|bulanan|per month|a month|every month|each month|monthly)\b/.test(clause)) return 'month'
  return 'week'
}

export function weekdayOf(clause: string): number | null {
  for (const [re, day] of WEEKDAYS) if (re.test(clause)) return day
  return null
}

const CONNECTORS = 'dan|lalu|serta|terus|kemudian|juga|and|then|also|plus'
// A connector or comma starts a new rule only when a new request follows; "about sales and marketing" stays one topic.
const NEXT_REQUEST = String.raw`(?=(?:\d|satu|dua|tiga|empat|lima|enam|tujuh|delapan|sembilan|sepuluh|se(?:buah)?\s|one|two|three|four|five|six|seven|eight|nine|ten|an?\s|riset|research|bikin|buat|cari|telusuri|pantau|make|create|generate|search|monitor|tiap|setiap|every|each))`
const SPLIT = new RegExp(String.raw`[\n.;]+|\s*,\s*(?:(?:${CONNECTORS})\s+)?${NEXT_REQUEST}|\s+(?:${CONNECTORS})\s+${NEXT_REQUEST}`)

function parseClause(clause: string): Rule | null {
  if (/\b(riset|research|telusuri|cari(?:kan)?|pantau|look up|search|monitor)\b/.test(clause)) {
    const per = perOf(clause)
    const day = weekdayOf(clause)
    const cadence = per === 'day' && day === null ? 'daily' : 'weekly'
    const rule: ResearchRule = { type: 'research', cadence, weekday: day ?? 0, topic: topicOf(clause), autoApprove: true }
    if (cadence === 'weekly' && day === null) rule.weekdayGuessed = true
    return rule
  }
  for (const [kind, re] of KIND_WORDS) {
    const m = re.exec(clause)
    if (!m) continue
    const count = countOf(clause, m.index)
    const per = perOf(clause)
    if (per === 'month') {
      return { type: 'content', kind, count: Math.max(1, Math.round(count / 4)), per: 'week', topic: topicOf(clause), monthly: count }
    }
    return { type: 'content', kind, count, per, topic: topicOf(clause) }
  }
  return null
}

export function parseInstruction(text: string): ParseResult {
  const language = languageOf(text)
  const clauses = text
    .toLowerCase()
    .replace(LANGUAGE_PHRASE, ' ')
    .replace(/[“”"]/g, '')
    .split(SPLIT)
    .map(s => s.trim())
    .filter(Boolean)

  const rules: Rule[] = []
  const unknown: string[] = []
  let shared = ''
  for (const clause of clauses) {
    const rule = parseClause(clause)
    if (rule) rules.push(rule)
    // A clause that only names a topic ("about leadership") applies to the rules around it.
    else if (topicOf(clause) || /^(soal|tentang|topik|about|topic)\b/.test(clause)) shared = topicOf(clause) || clause.replace(/^\S+\s*/, '')
    else if (!/^(tolong|bikin|buat|buatkan|ya|please|make|create|ok)$/.test(clause)) unknown.push(clause)
  }

  // One topic mentioned anywhere also covers rules that did not name their own.
  const topics = new Set(rules.map(r => r.topic).filter(Boolean))
  const fallback = shared || (topics.size === 1 ? [...topics][0] : '')
  for (const r of rules) if (!r.topic) r.topic = fallback
  // Topics are found in lower case; they keep the user's own capitals ("LLM", "HR").
  const lowered = text.toLowerCase()
  if (lowered.length === text.length) {
    for (const r of rules) {
      const at = r.topic ? lowered.indexOf(r.topic) : -1
      if (at >= 0) r.topic = text.slice(at, at + r.topic.length)
    }
  }
  return language ? { rules, unknown, language } : { rules, unknown }
}

export function weeklyTarget(rule: ContentRule): number {
  return rule.per === 'day' ? rule.count * 7 : rule.count
}

/** A video schedule is one engine run per day or per week; other counts have no matching cadence. */
export function videoCadence(rule: ContentRule): 'daily' | 'weekly' | null {
  const target = weeklyTarget(rule)
  return target === 7 ? 'daily' : target === 1 ? 'weekly' : null
}

export const dayName = (weekday: number) => t(`day.${weekday >= 0 && weekday <= 6 ? weekday : 0}` as Key)

export function describeRule(rule: Rule): string {
  const about = rule.topic ? t('rule.about', { topic: rule.topic }) : ''
  if (rule.type === 'research') {
    const when = rule.cadence === 'daily' ? t('rule.everyDay') : t('rule.everyWeekday', { day: dayName(rule.weekday) })
    return t('rule.research', { when, about })
  }
  return t('rule.content', {
    kind: kindLabel(rule.kind),
    count: rule.count,
    per: t(rule.per === 'day' ? 'ins.perDay' : 'ins.perWeek'),
    about: about || t('rule.wholeBrain'),
  })
}

export const monthNote = (rule: ContentRule) =>
  rule.monthly ? t('rule.monthNote', { count: rule.monthly, weekly: rule.count }) : null