import type { PrismaClient } from '@prisma/client'
import { createNotification, NotificationTypes } from './in-app-notification'

export type FinalDocRequirement = {
  id: string
  name: string
  acceptedMimeTypes: string[]
  isRequired: boolean
  uploaded: boolean
  file: { id: string; fileName: string; mimeType: string; bucket: string; objectKey: string; createdAt: Date } | null
}

export type FinalDocumentStatus = {
  roundId: string
  roundName: string
  deadline: Date | null
  deadlinePassed: boolean
  requirements: FinalDocRequirement[]
  allRequiredUploaded: boolean
}

/** Resolve the program's active LIVE_FINAL round, or null. */
export async function getActiveFinaleRound(prisma: PrismaClient, programId: string) {
  return prisma.round.findFirst({
    where: { competition: { programId }, roundType: 'LIVE_FINAL', status: 'ROUND_ACTIVE' },
    orderBy: { sortOrder: 'desc' },
    select: { id: true, name: true, windowCloseAt: true },
  })
}

/**
 * Per-project grand-final document status. Returns null unless the project is
 * enrolled (ProjectRoundState) in the program's active LIVE_FINAL round.
 */
export async function getFinalDocumentStatusForProject(
  prisma: PrismaClient,
  projectId: string,
): Promise<FinalDocumentStatus | null> {
  const project = await prisma.project.findUnique({
    where: { id: projectId },
    select: { id: true, programId: true },
  })
  if (!project) return null

  const round = await getActiveFinaleRound(prisma, project.programId)
  if (!round) return null

  const enrolled = await prisma.projectRoundState.findFirst({
    where: { projectId, roundId: round.id },
    select: { id: true },
  })
  if (!enrolled) return null

  const requirements = await prisma.fileRequirement.findMany({
    where: { roundId: round.id },
    orderBy: { sortOrder: 'asc' },
    select: { id: true, name: true, acceptedMimeTypes: true, isRequired: true },
  })

  const files = await prisma.projectFile.findMany({
    where: { projectId, roundId: round.id, requirementId: { in: requirements.map((r) => r.id) } },
    orderBy: { createdAt: 'desc' },
    select: { id: true, requirementId: true, fileName: true, mimeType: true, bucket: true, objectKey: true, createdAt: true },
  })
  const fileByReq = new Map<string, (typeof files)[number]>()
  for (const f of files) if (f.requirementId && !fileByReq.has(f.requirementId)) fileByReq.set(f.requirementId, f)

  const reqStatuses: FinalDocRequirement[] = requirements.map((r) => {
    const f = fileByReq.get(r.id) ?? null
    return {
      id: r.id, name: r.name, acceptedMimeTypes: r.acceptedMimeTypes, isRequired: r.isRequired,
      uploaded: !!f,
      file: f ? { id: f.id, fileName: f.fileName, mimeType: f.mimeType, bucket: f.bucket, objectKey: f.objectKey, createdAt: f.createdAt } : null,
    }
  })

  const required = reqStatuses.filter((r) => r.isRequired)
  const allRequiredUploaded = required.length > 0 && required.every((r) => r.uploaded)
  const deadline = round.windowCloseAt ?? null
  return {
    roundId: round.id,
    roundName: round.name,
    deadline,
    deadlinePassed: deadline ? new Date() > deadline : false,
    requirements: reqStatuses,
    allRequiredUploaded,
  }
}

function baseUrl(): string {
  return (process.env.NEXTAUTH_URL ?? 'http://localhost:3000').replace(/\/$/, '')
}

/** Build the reminder notification payload for one finalist team lead. */
async function remindTeam(
  prisma: PrismaClient,
  args: { projectId: string; projectTitle: string; deadline: Date | null; missing: string[]; leadUserId: string },
) {
  await createNotification({
    userId: args.leadUserId,
    type: NotificationTypes.GRAND_FINAL_DOCS_REMINDER,
    title: 'Upload your Grand Final documents',
    message: args.missing.length
      ? `Still needed for "${args.projectTitle}": ${args.missing.join(', ')}.`
      : `Please upload the final documents for "${args.projectTitle}".`,
    linkUrl: `${baseUrl()}/applicant/documents`,
    metadata: {
      projectId: args.projectId,
      projectTitle: args.projectTitle,
      deadline: args.deadline?.toISOString(),
      missing: args.missing,
    },
  })
}

/**
 * Manual admin reminder blast. Targets `projectIds` if given, else all finalist
 * teams (enrolled in the active LIVE_FINAL round) with missing required docs.
 */
export async function sendManualFinalDocReminders(
  prisma: PrismaClient,
  opts: { programId: string; projectIds?: string[]; actorId: string },
): Promise<{ sent: number }> {
  const round = await getActiveFinaleRound(prisma, opts.programId)
  if (!round) return { sent: 0 }

  const states = await prisma.projectRoundState.findMany({
    where: { roundId: round.id, ...(opts.projectIds ? { projectId: { in: opts.projectIds } } : {}) },
    select: { projectId: true },
  })

  let sent = 0
  for (const { projectId } of states) {
    const status = await getFinalDocumentStatusForProject(prisma, projectId)
    if (!status) continue
    const missing = status.requirements.filter((r) => r.isRequired && !r.uploaded).map((r) => r.name)
    // When projectIds explicitly provided, send regardless; else only if missing docs.
    if (!opts.projectIds && missing.length === 0) continue

    const project = await prisma.project.findUnique({
      where: { id: projectId },
      select: { title: true, teamMembers: { where: { role: 'LEAD' }, take: 1, select: { userId: true } } },
    })
    const leadUserId = project?.teamMembers[0]?.userId
    if (!project || !leadUserId) continue

    await remindTeam(prisma, {
      projectId, projectTitle: project.title, deadline: status.deadline, missing, leadUserId,
    })
    sent++
  }
  return { sent }
}