import { Prisma } from '@vector/db';
import type { LogRepairRequest, RepairListQuery } from '@vector/shared';
import { errors } from '../lib/http-error.js';
import { emit } from '../lib/webhook-emitter.js';
import * as partsSvc from './parts.js';
import * as partModelsSvc from './part-models.js';
import { resolveHost } from './fms.js';
import type { Actor, Tx } from './types.js';

// A Repair is the persistent log of a physical part swap on a host. The tech enters the broken
// serial + mpn + replacement serial; if the broken part isn't in the catalog we ingest it. The
// broken part is placed into the tech's custody (dropped in a bin later via the custody flow).
const repairInclude = {
  host: true,
  brokenPart: { include: { partModel: true, manufacturer: true } },
  replacement: { include: { partModel: true, manufacturer: true } },
  performedBy: { select: { id: true, username: true } },
  fm: { select: { id: true, status: true } },
} satisfies Prisma.RepairInclude;

export type RepairWithRelations = Prisma.RepairGetPayload<{ include: typeof repairInclude }>;

function buildWhere(q: RepairListQuery): Prisma.RepairWhereInput {
  const where: Prisma.RepairWhereInput = {};
  if (q.hostId) where.hostId = q.hostId;
  if (q.performedById) where.performedById = q.performedById;
  if (q.fmId) where.fmId = q.fmId;
  if (q.since) where.performedAt = { gte: new Date(q.since) };
  return where;
}

export async function list(tx: Tx, q: RepairListQuery) {
  const { page, pageSize } = q;
  const where = buildWhere(q);
  const [data, total] = await Promise.all([
    tx.repair.findMany({
      where,
      orderBy: { performedAt: 'desc' },
      include: repairInclude,
      skip: (page - 1) * pageSize,
      take: pageSize,
    }),
    tx.repair.count({ where }),
  ]);
  return { data, page, pageSize, total };
}

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

function repairPayload(r: RepairWithRelations) {
  return {
    id: r.id,
    host: { id: r.host.id, assetId: r.host.assetId, name: r.host.name },
    brokenPart: {
      id: r.brokenPart.id,
      serialNumber: r.brokenPart.serialNumber,
      mpn: r.brokenPart.partModel.mpn,
      state: r.brokenPart.state,
    },
    replacement: {
      id: r.replacement.id,
      serialNumber: r.replacement.serialNumber,
      mpn: r.replacement.partModel.mpn,
      state: r.replacement.state,
    },
    performedBy: r.performedBy,
    performedAt: r.performedAt.toISOString(),
    fmId: r.fmId,
  };
}

export async function log(
  tx: Tx,
  input: LogRepairRequest,
  actor: Actor,
): Promise<RepairWithRelations> {
  const host = await resolveHost(tx, input);

  // 1. Resolve replacement — must exist; must be SPARE, or a PENDING_REPAIR held by the actor.
  const replacement = await tx.part.findUnique({
    where: { serialNumber: input.replacementSerial },
    include: { partModel: true },
  });
  if (!replacement) {
    throw errors.badRequest(`Replacement part ${input.replacementSerial} not found`);
  }
  const heldForRepairByActor =
    replacement.state === 'PENDING_REPAIR' && replacement.custodianId === actor.id;
  if (replacement.state !== 'SPARE' && !heldForRepairByActor) {
    throw errors.badRequest(
      `Replacement part ${input.replacementSerial} is ${replacement.state}, must be SPARE or PENDING_REPAIR held by you`,
    );
  }

  // 2. Resolve broken — reuse if found, else ingest.
  let broken = await tx.part.findUnique({
    where: { serialNumber: input.brokenSerial },
    include: { partModel: true },
  });
  if (broken) {
    if (broken.hostId && broken.hostId !== host.id) {
      throw errors.badRequest(
        `Broken part ${input.brokenSerial} is currently on a different host`,
      );
    }
  } else {
    let pm: { id: string; manufacturerId: string };
    if (input.brokenPartModelId) {
      const existing = await tx.partModel.findUnique({ where: { id: input.brokenPartModelId } });
      if (!existing) throw errors.badRequest('Broken part model does not exist');
      pm = { id: existing.id, manufacturerId: existing.manufacturerId };
    } else {
      if (!input.brokenMpn || !input.brokenManufacturerId) {
        throw errors.badRequest(
          'Provide brokenPartModelId or both brokenMpn and brokenManufacturerId',
        );
      }
      pm = await partModelsSvc.upsertByMpn(tx, {
        manufacturerId: input.brokenManufacturerId,
        mpn: input.brokenMpn,
      });
    }
    const created = await tx.part.create({
      data: {
        serialNumber: input.brokenSerial,
        partModelId: pm.id,
        manufacturerId: pm.manufacturerId,
        state: 'DEPLOYED',
        hostId: host.id,
      },
      include: { partModel: true },
    });
    await tx.partEvent.create({
      data: {
        partId: created.id,
        userId: actor.id,
        type: 'CREATED',
        newValue: created.serialNumber,
      },
    });
    broken = created;
  }

  // 3. Optional FM link — must belong to the same host; we do NOT auto-close it.
  if (input.fmId) {
    const fm = await tx.fm.findUnique({ where: { id: input.fmId } });
    if (!fm) throw errors.badRequest('FM does not exist');
    if (fm.hostId !== host.id) {
      throw errors.badRequest('FM is on a different host than the repair');
    }
  }

  // 4. Custody state is driven by the broken model's destroyOnFail flag.
  const custodyState = broken.partModel.destroyOnFail
    ? 'PENDING_DESTRUCTION_IN_CUSTODY'
    : 'PENDING_DROP_IN_CUSTODY';

  // 5. Transition both parts through the standard parts.update machinery so every state
  //    and location change emits the usual PartEvents. The resolver clears host/bin
  //    automatically when entering custody / DEPLOYED.
  await partsSvc.update(
    tx,
    broken.id,
    { state: custodyState, custodianId: actor.id },
    actor,
  );
  await partsSvc.update(
    tx,
    replacement.id,
    { state: 'DEPLOYED', hostId: host.id },
    actor,
  );

  // 6. Persist the Repair row.
  const repair = await tx.repair.create({
    data: {
      hostId: host.id,
      brokenPartId: broken.id,
      replacementPartId: replacement.id,
      performedById: actor.id,
      fmId: input.fmId ?? null,
    },
    include: repairInclude,
  });

  // 7. Swap event on each part — so the part timeline shows the repair link.
  await tx.partEvent.createMany({
    data: [
      {
        partId: broken.id,
        userId: actor.id,
        type: 'PART_SWAPPED',
        field: 'role',
        oldValue: 'DEPLOYED',
        newValue: repair.id,
      },
      {
        partId: replacement.id,
        userId: actor.id,
        type: 'PART_SWAPPED',
        field: 'role',
        oldValue: 'SPARE',
        newValue: repair.id,
      },
    ],
  });

  void emit({ event: 'repair.logged', payload: { repair: repairPayload(repair) } });
  return repair;
}