import type { Prisma } from "@prisma/client";
import {
  emptyTexts,
  type MaterialLine,
  type ReportContent,
  type ReportTexts,
  type ReportType,
  type SignatureBlock,
} from "@/lib/reports/content";
import { dayWindow, localDateKey } from "@/lib/reports/dates";
import type { ServiceCtx } from "@/server/services/context";
import { requireVisibleWorkOrder } from "@/server/services/work-orders/visibility";

export type BuildContentInput = {
  workOrderId: string;
  type: ReportType;
  /** YYYY-MM-DD in tenant time zone */
  reportDate: string;
  reportNumber: string;
  version: number;
  /** keep edited texts; when omitted texts are prefilled from activity notes */
  texts?: ReportTexts;
  /** id of the report whose Signature row feeds the signature block */
  reportId?: string | null;
  /** fallback when the report has no Signature row (e.g. copied into a new version) */
  previousSignature?: SignatureBlock | null;
  technicianUserId: string | null;
  now?: Date;
};

export async function tenantTimeZone(ctx: ServiceCtx): Promise<string> {
  const s = await ctx.db.tenantSettings.findFirst({ select: { timezone: true } });
  return s?.timezone || "Europe/Berlin";
}

const joinLines = (...parts: Array<string | null | undefined>) => parts.filter((p) => p && p.trim()).join("\n");
const dec = (v: Prisma.Decimal | null | undefined) => (v == null ? null : v.toString());

function address(street?: string | null, houseNumber?: string | null, postalCode?: string | null, city?: string | null) {
  const line1 = [street, houseNumber].filter(Boolean).join(" ") || null;
  const line2 = [postalCode, city].filter(Boolean).join(" ") || null;
  return { line1, line2 };
}

/**
 * Build the report snapshot from the database (ARCHITEKTUR §4.7).
 * Daily report: only time entries, notes, photos and material usages of `reportDate`.
 * Completion report: the whole work order.
 * Access: the work order must be visible to the caller (workOrderScope).
 */
export async function buildReportContent(ctx: ServiceCtx, input: BuildContentInput): Promise<ReportContent> {
  const now = input.now ?? new Date();
  await requireVisibleWorkOrder(ctx, input.workOrderId, { id: true });
  const timeZone = await tenantTimeZone(ctx);
  const daily = input.type === "daily";
  const win = dayWindow(input.reportDate, timeZone);
  const inDay = daily ? { gte: win.start, lt: win.end } : undefined;

  const [wo, settings, tenant, entries, notes, photos, usages, plans, checklist, signature, technician] = await Promise.all([
    ctx.db.workOrder.findFirstOrThrow({
      where: { id: input.workOrderId },
      include: {
        customer: true,
        site: true,
        contact: true,
        orderType: { select: { name: true } },
        assignees: { include: { user: { select: { id: true, name: true } } } },
      },
    }),
    ctx.db.tenantSettings.findFirst({ select: { orgName: true, address: true, phone: true, email: true } }),
    ctx.db.user.findFirst({ where: { id: ctx.userId }, select: { tenant: { select: { name: true } } } }),
    ctx.db.timeEntry.findMany({
      where: { workSession: { workOrderId: input.workOrderId }, ...(inDay ? { startedAt: inDay } : {}) },
      orderBy: { startedAt: "asc" },
      select: { userId: true, type: true, startedAt: true, endedAt: true },
    }),
    ctx.db.activityNote.findMany({
      where: { workOrderId: input.workOrderId, deletedAt: null, ...(inDay ? { createdAt: inDay } : {}) },
      orderBy: { createdAt: "asc" },
      select: { kind: true, text: true },
    }),
    ctx.db.photo.findMany({
      where: { workOrderId: input.workOrderId, includeInReport: true, ...(inDay ? { takenAt: inDay } : {}) },
      orderBy: { takenAt: "asc" },
      include: { photoRequirement: { select: { label: true } } },
    }),
    ctx.db.materialUsage.findMany({
      where: { workOrderId: input.workOrderId, ...(inDay ? { createdAt: inDay } : {}) },
      orderBy: { createdAt: "asc" },
      include: { materialPlan: true },
    }),
    ctx.db.materialPlan.findMany({ where: { workOrderId: input.workOrderId }, orderBy: { sortOrder: "asc" } }),
    ctx.db.checklistItem.findMany({ where: { workOrderId: input.workOrderId }, orderBy: { sortOrder: "asc" } }),
    input.reportId ? ctx.db.signature.findFirst({ where: { reportId: input.reportId } }) : Promise.resolve(null),
    input.technicianUserId ? ctx.db.user.findFirst({ where: { id: input.technicianUserId }, select: { id: true, name: true } }) : Promise.resolve(null),
  ]);

  // ---- people & time ----
  const userIds = new Set<string>(entries.map((e) => e.userId));
  if (signature?.capturedById) userIds.add(signature.capturedById);
  const users = await ctx.db.user.findMany({ where: { id: { in: [...userIds] } }, select: { id: true, name: true } });
  const nameOf = new Map(users.map((u) => [u.id, u.name]));
  for (const a of wo.assignees) nameOf.set(a.user.id, a.user.name);

  const perKey = new Map<string, { userId: string; name: string; type: (typeof entries)[number]["type"]; minutes: number }>();
  let hasRunningEntries = false;
  for (const e of entries) {
    if (!e.endedAt) hasRunningEntries = true;
    const minutes = Math.max(0, Math.round(((e.endedAt ?? now).getTime() - e.startedAt.getTime()) / 60_000));
    const key = `${e.userId}|${e.type}`;
    const cur = perKey.get(key) ?? { userId: e.userId, name: nameOf.get(e.userId) ?? "—", type: e.type, minutes: 0 };
    cur.minutes += minutes;
    perKey.set(key, cur);
  }
  const timeLines = [...perKey.values()];
  const totalsByType: Record<string, number> = {};
  const byPerson = new Map<string, { userId: string; name: string; minutes: number }>();
  let totalMinutes = 0;
  for (const l of timeLines) {
    totalsByType[l.type] = (totalsByType[l.type] ?? 0) + l.minutes;
    if (l.type === "break") continue;
    totalMinutes += l.minutes;
    const p = byPerson.get(l.userId) ?? { userId: l.userId, name: l.name, minutes: 0 };
    p.minutes += l.minutes;
    byPerson.set(l.userId, p);
  }

  const staffIds = [...new Set(entries.map((e) => e.userId))];
  const staff = (staffIds.length ? staffIds : wo.assignees.map((a) => a.userId)).map((id) => ({ userId: id, name: nameOf.get(id) ?? "—" }));

  const workDates = daily
    ? [input.reportDate]
    : [...new Set(entries.map((e) => localDateKey(e.startedAt, timeZone)))].sort();

  // ---- texts (prefill from notes on create) ----
  const byKind = (...kinds: string[]) => joinLines(...notes.filter((n) => kinds.includes(n.kind)).map((n) => n.text));
  const texts: ReportTexts = input.texts ?? {
    ...emptyTexts(),
    workPerformed: byKind("work_done", "general"),
    deviations: byKind("deviation"),
    additionalWork: byKind("additional_work"),
    problems: byKind("problem", "not_executable"),
    openItems: byKind("follow_up"),
    nextSteps: "",
    hints: byKind("recommendation", "customer_note"),
  };

  // ---- materials ----
  const used: MaterialLine[] = [];
  const notUsed: MaterialLine[] = [];
  const additional: MaterialLine[] = [];
  const plansWithUsage = new Set<string>();
  for (const u of usages) {
    if (u.materialPlanId) plansWithUsage.add(u.materialPlanId);
    const planned = u.materialPlan ? dec(u.materialPlan.plannedQuantity) : null;
    const quantityDiffers = u.materialPlan ? !u.materialPlan.plannedQuantity.equals(u.actualQuantity) : false;
    const line: MaterialLine = {
      usageId: u.id,
      planId: u.materialPlanId,
      name: u.name,
      articleNumber: u.articleNumber,
      plannedQuantity: planned,
      actualQuantity: dec(u.actualQuantity),
      unit: u.unit,
      status: u.usageStatus,
      deviation: u.usageStatus !== "fully_used" || quantityDiffers,
      deviationReason: u.deviationReason,
      notes: u.notes,
      documented: true,
    };
    if (u.usageStatus === "additional" || !u.materialPlanId) additional.push({ ...line, deviation: true });
    else if (u.usageStatus === "not_used") notUsed.push(line);
    else used.push(line);
  }
  if (!daily) {
    for (const p of plans) {
      if (plansWithUsage.has(p.id)) continue;
      notUsed.push({
        usageId: null,
        planId: p.id,
        name: p.name,
        articleNumber: p.articleNumber,
        plannedQuantity: dec(p.plannedQuantity),
        actualQuantity: null,
        unit: p.unit,
        status: null,
        deviation: true,
        deviationReason: null,
        notes: p.notes,
        documented: false,
      });
    }
  }

  // ---- signature ----
  let signatureBlock: SignatureBlock | null = input.previousSignature ?? null;
  if (signature) {
    signatureBlock = {
      outcome: signature.outcome,
      signerName: signature.signerName,
      signerRole: signature.signerRole,
      signedAt: signature.signedAt.toISOString(),
      reason: signature.reason,
      confirmationText: signature.confirmationText,
      imageDocumentId: signature.imageDocumentId,
      capturedByName: signature.capturedById ? (nameOf.get(signature.capturedById) ?? null) : null,
    };
  }

  const customerName =
    wo.customer.companyName || [wo.customer.firstName, wo.customer.lastName].filter(Boolean).join(" ") || wo.customer.customerNumber || "—";

  return {
    schemaVersion: 1,
    type: input.type,
    reportNumber: input.reportNumber,
    version: input.version,
    reportDate: input.reportDate,
    generatedAt: now.toISOString(),
    tenant: {
      name: settings?.orgName || tenant?.tenant.name || "—",
      address: settings?.address ?? null,
      phone: settings?.phone ?? null,
      email: settings?.email ?? null,
      logoDocumentId: null, // TODO(settings): TenantSettings.logoKey is not a Document yet
    },
    customer: {
      id: wo.customer.id,
      number: wo.customer.customerNumber,
      name: customerName,
      address: address(wo.customer.street, wo.customer.houseNumber, wo.customer.postalCode, wo.customer.city),
    },
    site: wo.site ? { id: wo.site.id, name: wo.site.name, address: address(wo.site.street, wo.site.houseNumber, wo.site.postalCode, wo.site.city) } : null,
    contact: wo.contact
      ? { name: wo.contact.name, role: wo.contact.role, phone: wo.contact.phone ?? wo.contact.mobile, email: wo.contact.email }
      : null,
    workOrder: {
      id: wo.id,
      number: wo.number,
      externalOrderNumber: wo.externalOrderNumber,
      title: wo.title,
      description: wo.description,
      scope: wo.scope,
      orderType: wo.orderType?.name ?? null,
      signatureRequired: wo.signatureRequired,
    },
    workDates,
    staff,
    time: {
      entries: timeLines,
      totalsByType,
      totalsByPerson: [...byPerson.values()],
      totalMinutes,
      hasRunningEntries,
    },
    texts,
    materials: { used, notUsed, additional },
    photos: photos.map((p) => ({
      photoId: p.id,
      documentId: p.documentId,
      phase: p.phase,
      comment: p.comment,
      requirement: p.photoRequirement?.label ?? null,
      takenAt: p.takenAt.toISOString(),
    })),
    checklist: checklist.map((c) => ({ label: c.label, required: c.required, checked: c.checked, comment: c.comment })),
    signature: signatureBlock,
    technician: technician ? { userId: technician.id, name: technician.name } : null,
  };
}