import { Prisma } from '@vector/db';
import type {
  CreateRepairCommentRequest,
  CreateRepairJobRequest,
  RepairCommentListQuery,
  RepairJobListQuery,
  UpdateRepairJobRequest,
} from '@vector/shared';
import { errors } from '../lib/http-error.js';
import type { Actor, Tx } from './types.js';

const repairInclude = {
  host: true,
  assignee: { select: { id: true, username: true, email: true, role: true } },
  problemParts: {
    include: {
      part: {
        include: { partModel: true, manufacturer: true },
      },
    },
  },
} satisfies Prisma.RepairJobInclude;

const commentInclude = {
  user: { select: { id: true, username: true } },
} satisfies Prisma.RepairCommentInclude;

export async function list(tx: Tx, q: RepairJobListQuery) {
  const { page, pageSize, status, hostId, assigneeId, openOnly, problemPartId } = q;
  const where: Prisma.RepairJobWhereInput = {};
  if (status) where.status = status;
  if (hostId) where.hostId = hostId;
  if (assigneeId) where.assigneeId = assigneeId;
  if (openOnly) where.status = { in: ['PENDING', 'IN_PROGRESS'] };
  if (problemPartId) where.problemParts = { some: { partId: problemPartId } };

  const [data, total] = await Promise.all([
    tx.repairJob.findMany({
      where,
      orderBy: [{ status: 'asc' }, { openedAt: 'desc' }],
      include: repairInclude,
      skip: (page - 1) * pageSize,
      take: pageSize,
    }),
    tx.repairJob.count({ where }),
  ]);
  return { data, page, pageSize, total };
}

export function get(tx: Tx, id: string) {
  return tx.repairJob.findUnique({ where: { id }, include: repairInclude });
}

export function listForHost(tx: Tx, hostId: string) {
  return tx.repairJob.findMany({
    where: { hostId },
    orderBy: { openedAt: 'desc' },
    include: repairInclude,
  });
}

// Validates that the submitted problem-part ids are all attached to the named host.
// Parts that aren't on the host, or that don't exist, cause the whole repair create/update to fail
// — no silent skipping. Parts can be in any state (a repair can target a SPARE that was tagged as
// faulty during intake); the host-membership check is what matters.
async function validateProblemParts(tx: Tx, hostId: string, partIds: string[] | undefined) {
  if (!partIds || partIds.length === 0) return;
  const uniqueIds = [...new Set(partIds)];
  const rows = await tx.part.findMany({
    where: { id: { in: uniqueIds } },
    select: { id: true, hostId: true },
  });
  const found = new Map(rows.map((r) => [r.id, r]));
  for (const id of uniqueIds) {
    const row = found.get(id);
    if (!row) throw errors.badRequest(`Part ${id} does not exist`);
    if (row.hostId !== hostId) {
      throw errors.badRequest(`Part ${id} is not on the selected host`);
    }
  }
}

export async function create(
  tx: Tx,
  input: CreateRepairJobRequest,
  actor: Actor | null,
) {
  const host = await tx.host.findUnique({ where: { id: input.hostId } });
  if (!host) throw errors.notFound('Host');

  await validateProblemParts(tx, input.hostId, input.problemPartIds);

  try {
    const repair = await tx.repairJob.create({
      data: {
        hostId: input.hostId,
        assigneeId: input.assigneeId ?? null,
        notes: input.notes ?? null,
        problem: input.problem,
        status: 'PENDING',
        problemParts: input.problemPartIds && input.problemPartIds.length > 0
          ? { create: [...new Set(input.problemPartIds)].map((partId) => ({ partId })) }
          : undefined,
      },
      include: repairInclude,
    });
    if (input.problemPartIds && input.problemPartIds.length > 0) {
      await tx.partEvent.createMany({
        data: [...new Set(input.problemPartIds)].map((partId) => ({
          partId,
          userId: actor?.id ?? null,
          type: 'REPAIR_STARTED',
          newValue: repair.id,
        })),
      });
    }
    return repair;
  } catch (err) {
    if (err instanceof Prisma.PrismaClientKnownRequestError && err.code === 'P2003') {
      throw errors.badRequest('Invalid host, assignee, or part id');
    }
    throw err;
  }
}

export async function update(
  tx: Tx,
  id: string,
  input: UpdateRepairJobRequest,
  actor: Actor | null,
) {
  const current = await tx.repairJob.findUnique({
    where: { id },
    include: { problemParts: { select: { partId: true } }, host: true },
  });
  if (!current) throw errors.notFound('Repair');

  const data: Prisma.RepairJobUpdateInput = {};
  let terminalTransition: 'COMPLETED' | 'CANCELLED' | null = null;
  if (input.status !== undefined && input.status !== current.status) {
    data.status = input.status;
    const nowTerminal = input.status === 'COMPLETED' || input.status === 'CANCELLED';
    const wasTerminal = current.status === 'COMPLETED' || current.status === 'CANCELLED';
    if (nowTerminal && !wasTerminal) {
      data.closedAt = new Date();
      terminalTransition = input.status as 'COMPLETED' | 'CANCELLED';
    }
    if (!nowTerminal && wasTerminal) data.closedAt = null;
  }
  if (input.problem !== undefined) data.problem = input.problem;
  if (input.assigneeId !== undefined) {
    data.assignee = input.assigneeId
      ? { connect: { id: input.assigneeId } }
      : { disconnect: true };
  }
  if (input.notes !== undefined) data.notes = input.notes;

  // Problem-parts follow full-replace semantics: the request carries the final desired set.
  let addedPartIds: string[] = [];
  if (input.problemPartIds !== undefined) {
    await validateProblemParts(tx, current.hostId, input.problemPartIds);
    const existing = new Set(current.problemParts.map((p) => p.partId));
    const desired = new Set(input.problemPartIds);
    addedPartIds = [...desired].filter((p) => !existing.has(p));
    const removed = [...existing].filter((p) => !desired.has(p));
    if (removed.length > 0) {
      await tx.repairJobPart.deleteMany({
        where: { repairJobId: id, partId: { in: removed } },
      });
    }
    if (addedPartIds.length > 0) {
      await tx.repairJobPart.createMany({
        data: addedPartIds.map((partId) => ({ repairJobId: id, partId })),
      });
    }
  }

  const repair = await tx.repairJob.update({
    where: { id },
    data,
    include: repairInclude,
  });

  const userId = actor?.id ?? null;
  if (addedPartIds.length > 0) {
    await tx.partEvent.createMany({
      data: addedPartIds.map((partId) => ({
        partId,
        userId,
        type: 'REPAIR_STARTED',
        newValue: repair.id,
      })),
    });
  }
  if (terminalTransition !== null) {
    const partIds = repair.problemParts.map((p) => p.partId);
    if (partIds.length > 0) {
      await tx.partEvent.createMany({
        data: partIds.map((partId) => ({
          partId,
          userId,
          type: terminalTransition === 'COMPLETED' ? 'REPAIR_COMPLETED' : 'REPAIR_CANCELLED',
          newValue: repair.id,
        })),
      });
    }
  }

  return repair;
}

export async function remove(tx: Tx, id: string) {
  try {
    await tx.repairJob.delete({ where: { id } });
  } catch (err) {
    if (err instanceof Prisma.PrismaClientKnownRequestError && err.code === 'P2025') {
      throw errors.notFound('Repair');
    }
    throw err;
  }
}

export async function listComments(tx: Tx, repairJobId: string, q: RepairCommentListQuery) {
  const { page, pageSize } = q;
  const repair = await tx.repairJob.findUnique({ where: { id: repairJobId }, select: { id: true } });
  if (!repair) throw errors.notFound('Repair');
  const [data, total] = await Promise.all([
    tx.repairComment.findMany({
      where: { repairJobId },
      orderBy: { createdAt: 'asc' },
      include: commentInclude,
      skip: (page - 1) * pageSize,
      take: pageSize,
    }),
    tx.repairComment.count({ where: { repairJobId } }),
  ]);
  return { data, page, pageSize, total };
}

export async function addComment(
  tx: Tx,
  repairJobId: string,
  input: CreateRepairCommentRequest,
  actor: Actor | null,
) {
  const repair = await tx.repairJob.findUnique({
    where: { id: repairJobId },
    include: { problemParts: { select: { partId: true } } },
  });
  if (!repair) throw errors.notFound('Repair');

  const comment = await tx.repairComment.create({
    data: {
      repairJobId,
      userId: actor?.id ?? null,
      content: input.content,
    },
    include: commentInclude,
  });

  // Surface the comment on each problem-part's timeline so a part owner sees the activity
  // without having to navigate through to the repair.
  if (repair.problemParts.length > 0) {
    await tx.partEvent.createMany({
      data: repair.problemParts.map((p) => ({
        partId: p.partId,
        userId: actor?.id ?? null,
        type: 'REPAIR_COMMENTED',
        newValue: repair.id,
      })),
    });
  }

  return comment;
}