// Peach Codex — generation view.
//
// Two-step flow (see peach_codex_addendum.md):
//   1. words  — show the 12 recovery words and require the user to type 3
//               randomly-chosen ones correctly before generation can proceed.
//               The Codex PDF never contains recovery words; this is the
//               due-diligence gate that pushes the user to commit them to
//               paper separately.
//   2. gen    — run the popup-side `generateCodex` pipeline, surface progress,
//               trigger the PDF download.
//   3. done   — reminder to store the Codex and recovery words separately.
//
// Pro-gated: a non-Pro user is bounced to the license section on mount.
// Restoration (CodexRestoreView) stays free — a printed Codex must restore
// regardless of license state.

import { createSignal, createMemo, For, onMount, Show } from "solid-js";
import { sendMessage } from "../../shared/bridge";
import { isNativePlatform } from "../../shared/native";
import { RecoveryRuneBackground } from "../components/RecoveryRuneBackground";
import type {
  CodexDeps,
  CodexError,
  CodexManifest,
  CodexProgress,
  CodexVaultSnapshot,
} from "../../shared/codex-types";
import { STORAGE_KEY_LAST_GENERATED } from "../../shared/codex-types";
import {
  estimateCodexPages,
  generateCodex,
  pickConfirmationPositions,
} from "../codex/generate";
import { getReedSolomon } from "../codex/rs-loader";
import type { VaultEntry } from "../../shared/types";

interface CodexGenerateViewProps {
  isPro: boolean;
  onBack: () => void;
  onUpgradePro: () => void;
  onOpenSecurity: () => void;
  onVaultLocked: () => void;
}

type Step = "words" | "generating" | "done";


export function CodexGenerateView(props: CodexGenerateViewProps) {
  const [snapshot, setSnapshot] = createSignal<CodexVaultSnapshot | null>(null);
  const [estimatedPages, setEstimatedPages] = createSignal<number | null>(null);
  const [estimatedParity, setEstimatedParity] = createSignal<number | null>(null);
  const [loading, setLoading] = createSignal(true);
  const [loadError, setLoadError] = createSignal<string | null>(null);
  const [missingRecoveryWords, setMissingRecoveryWords] = createSignal(false);

  const [step, setStep] = createSignal<Step>("words");
  const [confirmPositions, setConfirmPositions] = createSignal<
    [number, number, number]
  >([3, 7, 11]);
  const [confirmInputs, setConfirmInputs] = createSignal<
    [string, string, string]
  >(["", "", ""]);

  const [progressStep, setProgressStep] = createSignal<string>("");
  const [progressCurrent, setProgressCurrent] = createSignal<number>(0);
  const [progressTotal, setProgressTotal] = createSignal<number>(0);

  const [genError, setGenError] = createSignal<string | null>(null);
  const [completed, setCompleted] = createSignal<CodexManifest | null>(null);

  onMount(async () => {
    if (!props.isPro) {
      props.onUpgradePro();
      return;
    }

    const res = (await sendMessage({
      type: "GET_CODEX_VAULT_DATA",
    })) as { ok: boolean; data?: CodexVaultSnapshot; error?: string };

    if (!res.ok || !res.data) {
      // Service worker restarted (MV3) and the vault re-locked in memory.
      // Route back to the lock screen exactly like the rest of the app does.
      if (res.error?.startsWith("VAULT_LOCKED")) {
        props.onVaultLocked();
        return;
      }
      setLoadError(res.error ?? "could not load vault data");
      setLoading(false);
      return;
    }

    setSnapshot(res.data);

    const words = res.data.recoveryWords;
    if (!words || words.length !== 12) {
      setMissingRecoveryWords(true);
      setLoading(false);
      return;
    }

    setConfirmPositions(pickConfirmationPositions());

    // Pre-warm the Reed-Solomon WASM so load failures surface before the
    // user completes the word-confirmation flow.
    try {
      await getReedSolomon();
    } catch (err) {
      setLoadError(
        `Failed to load Codex library: ${err instanceof Error ? err.message : String(err)}`
      );
      setLoading(false);
      return;
    }

    if (res.data.slotA) {
      try {
        const { pages, parityShards } = await estimateCodexPages(
          res.data.slotA,
          res.data.slotB,
        );
        setEstimatedPages(pages);
        setEstimatedParity(parityShards);
      } catch {
        // Estimation is informational; failure is non-fatal.
        setEstimatedPages(null);
        setEstimatedParity(null);
      }
    }

    setLoading(false);
  });

  const allCorrect = createMemo(() => {
    const snap = snapshot();
    const words = snap?.recoveryWords;
    if (!words || words.length !== 12) return false;
    const positions = confirmPositions();
    const inputs = confirmInputs();
    return positions.every(
      (pos, i) =>
        inputs[i]!.toLowerCase().trim() === words[pos - 1]!.toLowerCase(),
    );
  });

  function buildDeps(snap: CodexVaultSnapshot): CodexDeps {
    return {
      getSlotA: async () => snap.slotA,
      getSlotB: async () => snap.slotB,
      getLastModified: async () => snap.lastModified,
      // `getAllEntries` is consumed only as a count filter inside the
      // generator — synthesise placeholders so real entries don't cross
      // the popup boundary.
      getAllEntries: async () =>
        Array.from(
          { length: snap.entryCount },
          () => ({ deletedAt: null, archived: false }) as unknown as VaultEntry,
        ),
      getVerifyCode: async () => snap.verifyCode,
      isVaultUnlocked: () => snap.vaultUnlocked,
    };
  }

  function codexFilename(): string {
    const d = new Date();
    const y = d.getFullYear();
    const m = String(d.getMonth() + 1).padStart(2, "0");
    const day = String(d.getDate()).padStart(2, "0");
    return `peach-codex-${y}-${m}-${day}.pdf`;
  }

  function downloadPdf(bytes: Uint8Array): void {
    const a = document.createElement("a");
    a.download = codexFilename();
    if (isNativePlatform()) {
      // Capacitor WebView: blob: URLs are opaque to native, but data: URLs
      // are intercepted by MainActivity and written to public Downloads via
      // MediaStore. Encode in chunks to avoid blowing the call stack on
      // large PDFs.
      let bin = "";
      const chunk = 0x8000;
      for (let i = 0; i < bytes.length; i += chunk) {
        const slice = bytes.subarray(i, Math.min(i + chunk, bytes.length));
        bin += String.fromCharCode(...slice);
      }
      a.href = `data:application/pdf;base64,${btoa(bin)}`;
    } else {
      // Browser: copy into a fresh Uint8Array to ensure a tightly-owned
      // ArrayBuffer (Blob is happier with this than a subarray view).
      const owned = new Uint8Array(bytes);
      const blob = new Blob([owned.buffer], { type: "application/pdf" });
      a.href = URL.createObjectURL(blob);
      setTimeout(() => URL.revokeObjectURL(a.href), 4000);
    }
    document.body.appendChild(a);
    a.click();
    a.remove();
  }

  function explainCodexError(code: string, message: string): string {
    switch (code) {
      case "VAULT_LOCKED":
        return "your vault is locked. unlock and try again.";
      case "VAULT_EMPTY":
        return "your vault is empty — nothing to print yet.";
      case "PRO_REQUIRED":
        return "Codex generation is a Pro feature.";
      case "PDF_GENERATION_FAILED":
      case "AZTEC_GENERATION_FAILED":
        return "could not render the Codex. please try again.";
      case "COMPRESSION_ROUNDTRIP_FAILED":
      case "ERASURE_CODING_VERIFICATION_FAILED":
      case "ERASURE_CODING_CONTENT_MISMATCH":
      case "AZTEC_ROUNDTRIP_FAILED":
      case "AZTEC_CONTENT_MISMATCH":
      case "RECONSTRUCTION_SIMULATION_FAILED":
      case "RECONSTRUCTION_VERIFY_CODE_MISMATCH":
      case "RECONSTRUCTION_FINGERPRINT_MISMATCH":
      case "RECONSTRUCTION_COUNT_MISMATCH":
        return "a self-check failed while building the Codex. nothing was saved. please try again.";
      default:
        return message || "Codex generation failed.";
    }
  }

  const onProgress: CodexProgress = (s, current, total) => {
    setProgressStep(s);
    setProgressCurrent(current ?? 0);
    setProgressTotal(total ?? 0);
  };

  async function handleGenerate() {
    const snap = snapshot();
    if (!snap || !allCorrect() || step() === "generating") return;

    setGenError(null);
    setStep("generating");
    setProgressStep("compress");

    try {
      const result = await generateCodex(buildDeps(snap), onProgress);
      downloadPdf(result.pdfBytes);
      setCompleted(result.manifest);
      setStep("done");

      try {
        await chrome.storage.local?.set({
          [STORAGE_KEY_LAST_GENERATED]: Date.now(),
        });
      } catch {
        // Bookkeeping; failure is non-fatal.
      }
    } catch (err) {
      const codexErr = err as CodexError;
      const code = (codexErr && (codexErr as { code?: string }).code) ?? "";
      const message =
        err instanceof Error ? err.message : "Codex generation failed.";
      console.error("[Codex] generation failed:", code, message);
      setGenError(explainCodexError(code, message));
      setStep("words");
    }
  }

  function progressLabel(): string {
    switch (progressStep()) {
      case "compress":
        return "compressing vault";
      case "erasure":
        return "building chunks";
      case "aztec": {
        const total = progressTotal();
        const current = progressCurrent();
        if (total > 0) return `generating codes (${current} of ${total})`;
        return "generating codes";
      }
      case "verify":
        return "self-checking";
      case "pdf":
        return "creating PDF";
      default:
        return "preparing";
    }
  }

  function progressPercent(): number {
    const total = progressTotal();
    const current = progressCurrent();
    // Map step to a coarse progress band so the bar advances monotonically
    // even when intra-step progress (aztec N of M) is fine-grained.
    switch (progressStep()) {
      case "compress":
        return 8;
      case "erasure":
        return 18;
      case "aztec":
        if (total <= 0) return 30;
        return 30 + Math.floor((current / total) * 55); // 30 → 85
      case "verify":
        return 90;
      case "pdf":
        return 96;
      default:
        return 4;
    }
  }

  return (
    <div class="peach-overlay-view ov-enter-right" style="display:flex">
      <div class="peach-overlay-header">
        <button
          class="peach-btn peach-btn--ghost peach-btn--sm peach-icon-btn"
          onClick={props.onBack}
          aria-label="Back"
          disabled={step() === "generating"}
        >
          <svg width="7" height="12" viewBox="0 0 7 12" fill="none"
            stroke="currentColor" stroke-width="1.1"
            stroke-linecap="round" stroke-linejoin="round">
            <path d="M6 1L1 6L6 11" />
          </svg>
        </button>
        <span class="peach-overlay-title">peach codex</span>
        <div class="peach-overlay-spacer"></div>
      </div>

      <div class="peach-settings-body peach-codex-body peach-codex-body--runes">
        <RecoveryRuneBackground />

        <Show when={!props.isPro}>
          <p class="peach-hint">redirecting…</p>
        </Show>

        <Show when={props.isPro && loading()}>
          <p class="peach-hint">loading vault…</p>
        </Show>

        <Show when={props.isPro && !loading() && loadError()}>
          <p class="peach-hint peach-hint-error">{loadError()}</p>
        </Show>

        <Show when={props.isPro && !loading() && !loadError() && missingRecoveryWords()}>
          <div class="peach-settings-group peach-codex-intro">
            <p class="peach-codex-blurb">
              the Codex prints your encrypted vault as Aztec codes. before
              you can generate one, set up your 12 recovery words in
              Settings → Security.
            </p>
          </div>
          <button
            class="peach-btn peach-btn--accent peach-btn--md peach-btn--full"
            onClick={props.onOpenSecurity}
          >
            open Security settings
          </button>
        </Show>

        <Show
          when={
            props.isPro &&
            !loading() &&
            !loadError() &&
            !missingRecoveryWords() &&
            snapshot()
          }
        >
          <Show when={step() === "words"}>
            <div class="peach-codex-recovery-headline">
              <h2 class="peach-codex-recovery-title">your recovery words.</h2>
              <p class="peach-codex-recovery-body">
                write these down — store separately from your Codex.
              </p>
            </div>

            <ol class="peach-codex-words-grid" start={1}>
              <For each={snapshot()!.recoveryWords ?? []}>
                {(word, i) => (
                  <li class="peach-codex-word-row">
                    <span class="peach-codex-word-numeral">{i() + 1}</span>
                    <span class="peach-codex-word-text">{word}</span>
                  </li>
                )}
              </For>
            </ol>

            <Show when={estimatedPages() !== null}>
              <p class="peach-codex-meta">
                <strong>{estimatedPages()}</strong>{" "}
                {estimatedPages() === 1 ? "page" : "pages"} ·{" "}
                {snapshot()!.entryCount}{" "}
                {snapshot()!.entryCount === 1 ? "entry" : "entries"}
                <Show when={estimatedParity() !== null}>
                  {" "}· {estimatedParity()} redundancy codes
                </Show>
              </p>
            </Show>

            <div class="peach-codex-confirm-section">
              <p class="peach-codex-confirm-label">
                to continue, enter words {confirmPositions().join(", ")}:
              </p>
              <For each={confirmPositions()}>
                {(pos, i) => (
                  <div class="peach-codex-confirm-row">
                    <span class="peach-codex-confirm-pos">word {pos}</span>
                    <input
                      class="peach-codex-confirm-input"
                      type="text"
                      autocomplete="off"
                      autocorrect="off"
                      autocapitalize="none"
                      spellcheck={false}
                      value={confirmInputs()[i()]}
                      onInput={(e) => {
                        const next = [...confirmInputs()] as [
                          string,
                          string,
                          string,
                        ];
                        next[i()] = (e.target as HTMLInputElement).value;
                        setConfirmInputs(next);
                      }}
                      onKeyDown={(e) => {
                        if (e.key === "Enter" && allCorrect())
                          void handleGenerate();
                      }}
                    />
                  </div>
                )}
              </For>
            </div>

            <Show when={genError()}>
              <p class="peach-hint peach-hint-error peach-codex-error">
                {genError()}
              </p>
            </Show>

            <button
              class="peach-btn peach-btn--accent peach-btn--md peach-btn--full peach-codex-generate-btn"
              disabled={!allCorrect()}
              onClick={() => void handleGenerate()}
            >
              generate my Codex
            </button>
          </Show>

          <Show when={step() === "generating"}>
            <div class="peach-codex-recovery-headline">
              <h2 class="peach-codex-recovery-title">
                generating your codex…
              </h2>
            </div>

            <div class="peach-codex-progress-group">
              <p class="peach-codex-progress-label">
                <span>{progressLabel()}</span>
                <span class="peach-codex-verify-tag">
                  {snapshot()?.verifyCode}
                </span>
              </p>
              <div class="peach-codex-progress-track">
                <div
                  class="peach-codex-progress-fill"
                  style={`width:${progressPercent()}%`}
                />
              </div>
            </div>
          </Show>

          <Show when={step() === "done"}>
            <div class="peach-codex-recovery-headline">
              <h2 class="peach-codex-recovery-title">
                your codex is downloading.
              </h2>
            </div>

            <Show when={completed()}>
              <p class="peach-codex-meta">
                {completed()!.pageCount}{" "}
                {completed()!.pageCount === 1 ? "page" : "pages"} ·{" "}
                {completed()!.totalChunks} codes · verify code{" "}
                <span class="peach-codex-verify">
                  {completed()!.verifyCode}
                </span>
              </p>
            </Show>

            <div class="peach-codex-done-guidance">
              <div class="peach-codex-done-item">
                <span class="peach-codex-done-item-icon">🖨</span>
                <div>
                  <p class="peach-codex-done-item-title">
                    print on a laser printer
                  </p>
                  <p class="peach-codex-done-item-body">
                    laser prints last longer and scan more reliably than
                    inkjet. print at 100% scale — do not fit to page.
                  </p>
                </div>
              </div>

              <div class="peach-codex-done-item">
                <span class="peach-codex-done-item-icon">📦</span>
                <div>
                  <p class="peach-codex-done-item-title">make two copies</p>
                  <p class="peach-codex-done-item-body">
                    store one at home (fireproof box or safe) and one
                    somewhere else (trusted person, safety deposit box).
                    fire and flood can destroy a single copy.
                  </p>
                </div>
              </div>

              <div class="peach-codex-done-item">
                <span class="peach-codex-done-item-icon">🔑</span>
                <div>
                  <p class="peach-codex-done-item-title">
                    store separately from recovery words
                  </p>
                  <p class="peach-codex-done-item-body">
                    your 12 recovery words go somewhere different. together
                    they restore your vault without your passphrase. keep
                    them apart.
                  </p>
                </div>
              </div>

              <div class="peach-codex-done-item">
                <span class="peach-codex-done-item-icon">💾</span>
                <div>
                  <p class="peach-codex-done-item-title">also save the PDF</p>
                  <p class="peach-codex-done-item-body">
                    copy the PDF to a USB drive. Peach can import it
                    directly without needing to scan printed codes.
                  </p>
                </div>
              </div>
            </div>

            <p class="peach-codex-done-regenerate">
              regenerate your codex whenever you add many new entries.
            </p>

            <button
              class="peach-btn peach-btn--subtle peach-btn--sm peach-btn--full"
              onClick={() => {
                setCompleted(null);
                setGenError(null);
                setConfirmInputs(["", "", ""]);
                setConfirmPositions(pickConfirmationPositions());
                setStep("words");
              }}
            >
              generate another
            </button>
          </Show>
        </Show>
      </div>
    </div>
  );
}