import { api } from "./api";
import { createExportDeps } from "./exportDeps";
import { exportInvoice, issueAndArchive } from "./exportFlow";
import { parsePrefs } from "../pdf/model/prefs";
import { bytesEqual, dirOf, type StepLog } from "./selfTestSteps";
import type { BankAccount, Invoice, InvoiceInput, Settings } from "./types";

/**
 * The end-to-end invoice flow through the real IPC, run against the fresh database the self-test
 * launches with. The fresh database is neutral (no vendor, no bank), so the first step provisions a
 * fake vendor and bank the way the setup wizard would.
 */

const today = () => {
  const d = new Date();
  const p = (n: number) => String(n).padStart(2, "0");
  return `${d.getFullYear()}-${p(d.getMonth() + 1)}-${p(d.getDate())}`;
};

const hex = (bytes: Uint8Array) => Array.from(bytes.slice(0, 5), (b) => b.toString(16).padStart(2, "0")).join("");
const kb = (n: number) => `${(n / 1024).toFixed(1)} KB`;

export async function runE2eSteps(log: StepLog, reportPath: string): Promise<void> {
  const outDir = dirOf(reportPath);
  const searchablePath = `${outDir}/e2e-searchable.pdf`;
  const flattenedPath = `${outDir}/e2e-flattened.pdf`;

  let s!: Settings;
  let bank!: BankAccount;
  let invoice: Invoice | null = null;

  const loaded = await log.run("e2e: provision vendor and bank, get settings", async () => {
    s = await api.getSettings();
    let banks = await api.listBanks();
    if (banks.length === 0) {
      const saved = await api.saveBank({
        id: null,
        label: "Primary",
        bankName: "Self-test Bank",
        accountName: "Self-test Vendor",
        accountNo: "000000000000",
        branch: "000001",
        ifsc: "TEST0000001",
        isDefault: true,
      });
      s = await api.saveSettings({
        ...s,
        vendorName: s.vendorName || "Self-test Vendor",
        vendorAddress: s.vendorAddress || "1 Test Road, Bengaluru - 560001",
        vendorStateCode: s.vendorStateCode || "29",
        defaultBankId: saved.id,
        onboarded: true,
      });
      banks = await api.listBanks();
    }
    const found = banks.find((b) => b.id === s.defaultBankId) ?? banks[0];
    if (!found) throw new Error("no bank account after provisioning");
    bank = found;
    return `${s.vendorName}, ${s.gstRegistration}, state ${s.vendorStateCode}, bank "${bank.label}"`;
  });
  if (!loaded.ok) return;

  const prefs = parsePrefs(s.renderPrefs);
  const input: InvoiceInput = {
    invoiceDate: today(),
    dueDate: "",
    clientId: null,
    clientName: "Self-test Client Pvt Ltd",
    clientAddress: "42 Example Road, Indiranagar, Bengaluru - 560038",
    clientGstin: "",
    poNumber: "PO-SELFTEST",
    placeOfSupplyStateCode: "",
    discount: 0,
    taxType: s.gstRegistration === "unregistered" ? "none" : s.defaultTaxType,
    taxRate: s.gstRegistration === "unregistered" ? 0 : s.defaultTaxRate,
    reverseCharge: false,
    bankAccountId: bank.id,
    signaturePath: null,
    notes: "Self-test invoice",
    saveClient: false,
    draftId: null,
    items: [
      { description: "Voice-over, 60 second spot", mode: "fixed", rate: 0, unit: "unit", quantity: 1, amount: 4500, sortOrder: 0 },
      { description: "Studio session", mode: "rate", rate: 1200, unit: "hour", quantity: 2, amount: 0, sortOrder: 1 },
      { description: "Revision round", mode: "fixed", rate: 0, unit: "unit", quantity: 1, amount: 850.5, sortOrder: 2 },
    ],
  };

  const deps = createExportDeps({ settings: s, bank });
  // What the export wrote, per path, so the checks need no way to read arbitrary files back.
  const written = new Map<string, Uint8Array>();
  const exportWith = (mode: "searchable" | "flattened", source: "original" | "rerender", path: string) =>
    exportInvoice(
      { invoice: inv, mode, source },
      {
        ...deps,
        save: async () => path,
        writeExportFile: async (p, bytes) => {
          written.set(p, bytes);
          return deps.writeExportFile(p, bytes);
        },
      },
    );

  let inv!: Invoice;
  const issued = await log.run("e2e: issue and archive", async () => {
    const outcome = await issueAndArchive(input, prefs, deps);
    invoice = outcome.invoice;
    return {
      ok: outcome.archived,
      detail: `${outcome.invoice.number} (id ${outcome.invoice.id}), total ${outcome.invoice.total}, archived=${outcome.archived}${outcome.error ? `, error: ${outcome.error}` : ""}`,
    };
  });
  if (!issued.ok || !invoice) return;
  inv = invoice as Invoice;

  await log.run("e2e: archive status", async () => {
    const st = await api.archiveStatus(inv.id);
    const matches = st.archived && st.sha256 === inv.archivedPdfSha256 && st.fingerprint === inv.archivedFingerprint;
    return { ok: matches, detail: `archived=${st.archived}, sha ${st.sha256?.slice(0, 12)}, fingerprint ${st.fingerprint?.slice(0, 12)}, matches issue result: ${matches}` };
  });

  await log.run("e2e: export searchable original", async () => {
    const r = await exportWith("searchable", "original", searchablePath);
    return { ok: r?.path === searchablePath, detail: `wrote ${r?.path}` };
  });

  await log.run("e2e: export flattened original", async () => {
    const r = await exportWith("flattened", "original", flattenedPath);
    return { ok: r?.path === flattenedPath, detail: `wrote ${r?.path}` };
  });

  await log.run("e2e: export searchable re-render", async () => {
    const r = await exportWith("searchable", "rerender", `${outDir}/e2e-rerender.pdf`);
    return { ok: !!r && r.identicalToIssued !== undefined, detail: `identicalToIssued=${r?.identicalToIssued}` };
  });

  await log.run("e2e: archive bytes equal the searchable export", async () => {
    const archived = await api.readArchive(inv.id);
    const exported = written.get(searchablePath);
    const eq = !!exported && bytesEqual(archived, exported);
    return { ok: eq, detail: `${kb(archived.byteLength)} header ${hex(archived)}, equal to export file: ${eq}` };
  });

  await log.run("e2e: last export directory", async () => {
    const dir = await api.getLastExportDir();
    return { ok: dir === outDir, detail: `${dir} (expected ${outDir})` };
  });

  await log.run("e2e: cancel keeps archive readable", async () => {
    const before = await api.readArchive(inv.id);
    const cancelled = await api.cancelInvoice(inv.id, "self-test");
    const after = await api.readArchive(inv.id);
    const st = await api.archiveStatus(inv.id);
    return {
      ok: cancelled.status === "cancelled" && st.archived && bytesEqual(before, after),
      detail: `status ${cancelled.status}, archive still ${kb(after.byteLength)}, unchanged: ${bytesEqual(before, after)}`,
    };
  });

  await log.run("e2e: archiving different bytes is refused", async () => {
    const other = new TextEncoder().encode("%PDF-1.4\n% a different file\n");
    const before = await api.readArchive(inv.id);
    try {
      await api.archivePdf(inv.id, other, "tampered");
    } catch (e) {
      const msg = String(e);
      const after = await api.readArchive(inv.id);
      const intact = bytesEqual(after, before);
      return { ok: /cannot be replaced/.test(msg) && intact, detail: `refused: ${msg}; archive unchanged: ${intact}` };
    }
    return { ok: false, detail: "the replacement was accepted" };
  });
}