import {
  sendInteractiveButtons,
  sendInteractiveList,
  sendTextMessage,
  type InteractiveButton,
  type InteractiveListSection,
} from '@/lib/whatsapp/meta-api'
import { decrypt } from '@/lib/whatsapp/encryption'
import {
  sanitizePhoneForMeta,
  isValidE164,
  phoneVariants,
  isRecipientNotAllowedError,
} from '@/lib/whatsapp/phone-utils'
import { supabaseAdmin } from './admin-client'

// ------------------------------------------------------------
// Flows-side Meta sender (interactive variants).
//
// Mirrors src/lib/automations/meta-send.ts (engineSendText /
// engineSendTemplate) but emits interactive button + list messages.
// Kept separate from the automations file so the two engines don't
// fight over each other's shape — once both stabilize, the
// phone-variant retry + DB persistence are obvious extraction
// candidates into a shared base.
//
// PR #1 ships this in isolation: callers don't exist yet. PR #2
// brings the flow runner online and wires it up. Shipping it now
// keeps the foundation PR self-contained and unit-testable.
// ------------------------------------------------------------

interface SendTextEngineArgs {
  userId: string
  conversationId: string
  contactId: string
  text: string
}

/**
 * Send a plain-text WhatsApp message from the Flows engine.
 *
 * Used by the runner's `send_message` and `collect_input` nodes —
 * both prompt the customer with text and either auto-advance (the
 * send_message case) or suspend awaiting a text reply (collect_input).
 *
 * Wraps the same phone-variant retry + DB persistence pattern as the
 * interactive senders; the duplication will be DRY'd into a shared
 * `engineSendBase` once the v2 features (templates with variables,
 * media sends) settle.
 */
export async function engineSendText(
  args: SendTextEngineArgs,
): Promise<{ whatsapp_message_id: string }> {
  const db = supabaseAdmin()

  const { data: contact, error: contactErr } = await db
    .from('contacts')
    .select('id, phone')
    .eq('id', args.contactId)
    .eq('user_id', args.userId)
    .maybeSingle()
  if (contactErr || !contact?.phone) {
    throw new Error('contact not found for this user')
  }

  const sanitized = sanitizePhoneForMeta(contact.phone)
  if (!isValidE164(sanitized)) {
    throw new Error(`contact phone invalid: ${contact.phone}`)
  }

  const { data: config, error: configErr } = await db
    .from('whatsapp_config')
    .select('*')
    .eq('user_id', args.userId)
    .single()
  if (configErr || !config) {
    throw new Error('WhatsApp not configured for this account')
  }

  const accessToken = decrypt(config.access_token)

  const attempt = async (phone: string): Promise<string> => {
    const r = await sendTextMessage({
      phoneNumberId: config.phone_number_id,
      accessToken,
      to: phone,
      text: args.text,
    })
    return r.messageId
  }

  const variants = phoneVariants(sanitized)
  let workingPhone = sanitized
  let waMessageId = ''
  let lastError: unknown = null
  for (const v of variants) {
    try {
      waMessageId = await attempt(v)
      workingPhone = v
      lastError = null
      break
    } catch (err) {
      const msg = err instanceof Error ? err.message : String(err)
      if (!isRecipientNotAllowedError(msg)) throw err
      lastError = err
    }
  }
  if (lastError) throw lastError

  if (workingPhone !== sanitized) {
    await db.from('contacts').update({ phone: workingPhone }).eq('id', contact.id)
  }

  const { error: msgErr } = await db.from('messages').insert({
    conversation_id: args.conversationId,
    sender_type: 'bot',
    content_type: 'text',
    content_text: args.text,
    message_id: waMessageId,
    status: 'sent',
  })
  if (msgErr) {
    throw new Error(`sent to Meta but DB insert failed: ${msgErr.message}`)
  }

  await db
    .from('conversations')
    .update({
      last_message_text: args.text,
      last_message_at: new Date().toISOString(),
      updated_at: new Date().toISOString(),
    })
    .eq('id', args.conversationId)

  return { whatsapp_message_id: waMessageId }
}

interface SendInteractiveButtonsEngineArgs {
  userId: string
  conversationId: string
  contactId: string
  bodyText: string
  buttons: InteractiveButton[]
  headerText?: string
  footerText?: string
}

interface SendInteractiveListEngineArgs {
  userId: string
  conversationId: string
  contactId: string
  bodyText: string
  buttonLabel: string
  sections: InteractiveListSection[]
  headerText?: string
  footerText?: string
}

/**
 * Send an interactive-button WhatsApp message from the Flows engine.
 *
 * Persists the outgoing message to `messages` with
 * `content_type='interactive'` and `sender_type='bot'` so the inbox
 * surfaces it with the "Button reply" affordance and the conversation
 * thread reflects the bot's prompt.
 *
 * Returns the Meta message id so the caller (engine) can stash it on
 * the `flow_runs.last_prompt_message_id` field for later reference.
 */
export async function engineSendInteractiveButtons(
  args: SendInteractiveButtonsEngineArgs,
): Promise<{ whatsapp_message_id: string }> {
  return sendInteractiveViaMeta({ ...args, kind: 'buttons' })
}

/**
 * Send an interactive-list WhatsApp message from the Flows engine.
 * Used when the flow needs more than 3 options (Meta's button cap).
 */
export async function engineSendInteractiveList(
  args: SendInteractiveListEngineArgs,
): Promise<{ whatsapp_message_id: string }> {
  return sendInteractiveViaMeta({ ...args, kind: 'list' })
}

type SendInput =
  | (SendInteractiveButtonsEngineArgs & { kind: 'buttons' })
  | (SendInteractiveListEngineArgs & { kind: 'list' })

async function sendInteractiveViaMeta(
  input: SendInput,
): Promise<{ whatsapp_message_id: string }> {
  const db = supabaseAdmin()

  // Scope the contact lookup by user_id — same defense-in-depth
  // rationale as automations/meta-send.ts. Service-role client
  // bypasses RLS, so an attacker who could call into the engine
  // with a contact_id from another tenant would otherwise send
  // through their own WhatsApp config to a stranger's number.
  const { data: contact, error: contactErr } = await db
    .from('contacts')
    .select('id, phone')
    .eq('id', input.contactId)
    .eq('user_id', input.userId)
    .maybeSingle()
  if (contactErr || !contact?.phone) {
    throw new Error('contact not found for this user')
  }

  const sanitized = sanitizePhoneForMeta(contact.phone)
  if (!isValidE164(sanitized)) {
    throw new Error(`contact phone invalid: ${contact.phone}`)
  }

  const { data: config, error: configErr } = await db
    .from('whatsapp_config')
    .select('*')
    .eq('user_id', input.userId)
    .single()
  if (configErr || !config) {
    throw new Error('WhatsApp not configured for this account')
  }

  const accessToken = decrypt(config.access_token)

  const attempt = async (phone: string): Promise<string> => {
    if (input.kind === 'buttons') {
      const r = await sendInteractiveButtons({
        phoneNumberId: config.phone_number_id,
        accessToken,
        to: phone,
        bodyText: input.bodyText,
        buttons: input.buttons,
        headerText: input.headerText,
        footerText: input.footerText,
      })
      return r.messageId
    }
    const r = await sendInteractiveList({
      phoneNumberId: config.phone_number_id,
      accessToken,
      to: phone,
      bodyText: input.bodyText,
      buttonLabel: input.buttonLabel,
      sections: input.sections,
      headerText: input.headerText,
      footerText: input.footerText,
    })
    return r.messageId
  }

  // Same phone-variant retry as automations/meta-send.ts. Numbers
  // registered with/without a trunk 0 + Meta's sandbox quirks all
  // need this to reliably land a message.
  const variants = phoneVariants(sanitized)
  let workingPhone = sanitized
  let waMessageId = ''
  let lastError: unknown = null
  for (const v of variants) {
    try {
      waMessageId = await attempt(v)
      workingPhone = v
      lastError = null
      break
    } catch (err) {
      const msg = err instanceof Error ? err.message : String(err)
      if (!isRecipientNotAllowedError(msg)) throw err
      lastError = err
    }
  }
  if (lastError) throw lastError

  if (workingPhone !== sanitized) {
    await db.from('contacts').update({ phone: workingPhone }).eq('id', contact.id)
  }

  // Persist the bot's prompt to the messages table so it appears in
  // the inbox. content_type='interactive' is supported as of
  // migration 010; sender_type='bot' distinguishes flow sends from
  // manual agent sends (the conversation list preview will pick up
  // last_message_text as a sensible summary).
  //
  // We do NOT set interactive_reply_id here — that column is reserved
  // for the customer's tap on this message, populated by the webhook
  // when their reply arrives.
  const { error: msgErr } = await db.from('messages').insert({
    conversation_id: input.conversationId,
    sender_type: 'bot',
    content_type: 'interactive',
    content_text: input.bodyText,
    message_id: waMessageId,
    status: 'sent',
  })
  if (msgErr) {
    throw new Error(`sent to Meta but DB insert failed: ${msgErr.message}`)
  }

  await db
    .from('conversations')
    .update({
      last_message_text: input.bodyText,
      last_message_at: new Date().toISOString(),
      updated_at: new Date().toISOString(),
    })
    .eq('id', input.conversationId)

  return { whatsapp_message_id: waMessageId }
}