"use server";

import { revalidatePath } from "next/cache";
import type { ReportActionState } from "@/lib/reports/action-state";
import { moduleGuard } from "@/server/action-guard";
import { ctxFromGuard, ServiceError } from "@/server/services/context";
import { requireVisibleReport } from "@/server/services/reports/common";
import { captureSignature } from "@/server/services/reports/signature";
// TODO(merge L4): signature PNG could go through POST /api/v1/uploads once available
import { storeFile } from "@/server/services/documents/store";
import { errorState, okState, str } from "./_state";

const guard = moduleGuard("reports");
const MAX_PNG_BYTES = 2 * 1024 * 1024;

/**
 * Capture signature or documented exception. Form fields: reportId, outcome, signerName, signerRole, reason,
 * confirmationText, signaturePng (data:image/png;base64,… from the signature pad; only for outcome=signed).
 */
export async function captureSignatureAction(_prev: ReportActionState, fd: FormData): Promise<ReportActionState> {
  try {
    const ctx = ctxFromGuard(await guard("report:write"));
    const reportId = str(fd, "reportId") ?? "";
    const outcome = str(fd, "outcome") ?? "";
    const report = await requireVisibleReport(ctx, reportId);

    let imageDocumentId: string | null = null;
    const png = str(fd, "signaturePng") ?? "";
    if (outcome === "signed") {
      const m = /^data:image\/png;base64,([A-Za-z0-9+/=]+)$/.exec(png);
      if (!m) throw new ServiceError("invalid", "signature image required", { field: "image" });
      const bytes = Buffer.from(m[1], "base64");
      if (bytes.byteLength > MAX_PNG_BYTES) throw new ServiceError("invalid", "signature image too large", { field: "image" });
      if (!str(fd, "signerName")?.trim()) throw new ServiceError("invalid", "signer name required", { field: "signerName" });
      const wo = await ctx.db.workOrder.findFirstOrThrow({ where: { id: report.workOrderId }, select: { id: true, customerId: true, siteId: true } });
      const doc = await storeFile(ctx, {
        bytes,
        fileName: `unterschrift-${report.id}.png`,
        declaredMime: "image/png",
        category: "signature",
        visibility: "customer_report",
        links: { customerId: wo.customerId, siteId: wo.siteId, workOrderId: wo.id },
      });
      imageDocumentId = doc.id;
    }

    try {
      await captureSignature(ctx, {
        reportId,
        outcome: outcome as Parameters<typeof captureSignature>[1]["outcome"],
        signerName: str(fd, "signerName"),
        signerRole: str(fd, "signerRole"),
        reason: str(fd, "reason"),
        confirmationText: str(fd, "confirmationText") ?? "",
        imageDocumentId,
      });
    } catch (err) {
      if (imageDocumentId) await ctx.db.document.update({ where: { id: imageDocumentId }, data: { deletedAt: new Date() } });
      throw err;
    }
    revalidatePath(`/m/orders/${report.workOrderId}/sign`);
    revalidatePath(`/m/orders/${report.workOrderId}/report`);
    revalidatePath(`/reports/${report.id}`);
    return okState(report.id);
  } catch (err) {
    return errorState(err);
  }
}