// The page model of one inspection: every value the inspector shows, built
// from the library's Inspection with no DOM and no clock, so that it can be
// tested without a browser.

import {
  canonicalJSON,
  chainHashHex,
  compactDateKey,
  DKC_PRELUDE_SIZE,
  type ErrorCode,
  type Extension,
  type ExtensionRegistry,
  type Format,
  formatRFC3339,
  type Inspection,
  inspectView,
  type InspectView,
  policyName,
  STANZA_TLOCK,
  type StanzaInfo,
  toHex,
  type Unusable,
} from '../dkc/index.ts';
import { cborView, type Diagnostic } from './diagnostic.ts';
import { cliJSON, displayText, instantToEpochMs, INSPECT_STEPS, printableText, stepGloss, stepName } from './format.ts';

export type StepState = 'ok' | 'failed' | 'not-run';

/** One of the eight steps, as the CLI reports it, or not run. */
export interface StepRow {
  readonly step: number;
  /** The CLI name, for example "header validation". */
  readonly name: string;
  /** What the step checks, in Spanish. */
  readonly gloss: string;
  readonly state: StepState;
  /** The pass detail or the error message; undefined when not run. */
  readonly detail?: string;
  /** The normative code of a failed step. */
  readonly code?: ErrorCode;
}

/** A value read from the capsule next to the one the pinned profile expects. */
export interface Comparison {
  readonly label: string;
  readonly found: string | undefined;
  readonly expected: string;
  readonly match: boolean;
}

/** One PUBLIC_HEADER extension, with every view of its data. */
export interface ExtensionRow {
  readonly critical: boolean;
  /** extension_id as shown: as it is, or quoted and escaped. */
  readonly id: string;
  /** The identifier holds non-printable characters and is shown escaped. */
  readonly idEscaped: boolean;
  readonly version: number;
  /** Whether this reader implements the extension. */
  readonly known: boolean;
  /** The data error of a known noncritical extension the reader cannot use. */
  readonly unusable?: string;
  /** Data length in bytes; 0 when the extension carries no data. */
  readonly length: number;
  /** Data in lowercase hexadecimal. */
  readonly hex: string;
  /** The data as text when it is valid printable UTF-8. */
  readonly text?: string;
  /** Informative diagnostic notation when the data is CBOR of the §58 profile. */
  readonly cbor?: Diagnostic;
}

export interface CapsuleFacts {
  readonly capsuleId: string;
  readonly accessPolicy: string;
  /** The compact dk1_ DateKey. */
  readonly dateKey: string;
  /** Its decoded payload, the canonical JSON of spec §18. */
  readonly dateKeyJSON: string;
  /** The network field of the DateKey: the profile_id. */
  readonly network: string;
  readonly round: number;
}

export interface ProfileFacts {
  readonly id: string;
  readonly provider: string;
  readonly network: string;
  readonly chainHash: string;
  readonly period: number;
  readonly genesis: string;
  readonly scheme: string;
}

export interface PreludeFacts {
  /** The 16 prelude bytes in hexadecimal. */
  readonly hex: string;
  readonly magic: string;
  /**
   * VERSION, the capsule format (spec §22): format 1 does not hide the
   * number of credentials nor the exact length of the content (§55.2, §70).
   */
  readonly format: Format;
  readonly flags: string;
  readonly reserved: string;
  readonly publicHeaderLen: number;
  readonly sealedControlLen: number;
  /** Where PAYLOAD_AGE starts. */
  readonly payloadOffset: number;
  /** Bytes of PAYLOAD_AGE, when the file reaches its start. */
  readonly payloadLength?: number;
}

export interface Report {
  readonly fileName: string;
  /** Size of the whole file. */
  readonly size: number;
  /** Bytes read for the inspection (see inspectedLength). */
  readonly readLength: number;
  readonly valid: boolean;
  readonly failure?: { readonly step: number; readonly code: ErrorCode; readonly message: string };
  /** Always the eight steps, in order. */
  readonly steps: readonly StepRow[];
  /** The view of `datekeys inspect -json`. */
  readonly view: InspectView;
  /** Its exact JSON text. */
  readonly json: string;
  readonly capsule?: CapsuleFacts;
  readonly profile?: ProfileFacts;
  /** The effective round time, once step 7 passed. */
  readonly unlock?: { readonly rfc3339: string; readonly epochMs: number | undefined };
  readonly prelude?: PreludeFacts;
  readonly outerStanzas?: readonly StanzaInfo[];
  readonly payloadStanzas?: readonly StanzaInfo[];
  /** The tlock stanza arguments against the pinned profile. */
  readonly tlock?: readonly Comparison[];
  /** Critical extensions first, then noncritical; undefined until PUBLIC_HEADER decoded. */
  readonly extensions?: readonly ExtensionRow[];
  /**
   * The public note of the header (spec §24.1): text of the creator that
   * nobody has checked, or `unusable` when the header holds a note that
   * breaks the rules of text, which is not shown. Undefined without a note.
   */
  readonly note?: { readonly text: string } | { readonly unusable: true };
}

export interface ReportInput {
  readonly fileName: string;
  /** The bytes that were inspected: the file or its inspected prefix. */
  readonly bytes: Uint8Array;
  /** Size of the whole file. */
  readonly size: number;
  readonly inspection: Inspection;
  /** The extension registry given to the inspection, if any. */
  readonly extensions?: ExtensionRegistry;
}

const hex8 = (v: number): string => `0x${v.toString(16).padStart(2, '0')}`;

export function buildReport(input: ReportInput): Report {
  const { inspection: r, bytes, size } = input;
  const view = inspectView(r, input.fileName);
  const out: {
    -readonly [K in keyof Report]: Report[K];
  } = {
    fileName: input.fileName,
    size,
    readLength: bytes.length,
    valid: r.error === undefined,
    steps: steps(r),
    view,
    json: cliJSON(view),
  };
  if (r.error !== undefined) {
    const last = r.checks.at(-1)!;
    out.failure = { step: last.step, code: r.error.code, message: r.error.message };
  }

  if (r.prelude !== undefined && r.payloadOffset !== undefined) {
    const p: { -readonly [K in keyof PreludeFacts]: PreludeFacts[K] } = {
      hex: toHex(bytes.subarray(0, DKC_PRELUDE_SIZE)),
      magic: 'DKC1',
      format: r.prelude.format,
      flags: hex8(bytes[5]!),
      reserved: `0x${toHex(bytes.subarray(6, 8))}`,
      publicHeaderLen: r.prelude.publicHeaderLen,
      sealedControlLen: r.prelude.sealedControlLen,
      payloadOffset: r.payloadOffset,
    };
    if (size >= r.payloadOffset) p.payloadLength = size - r.payloadOffset;
    out.prelude = p;
  }

  const h = r.header;
  if (h !== undefined) {
    out.capsule = {
      capsuleId: toHex(h.capsuleId),
      accessPolicy: policyName(h.policy),
      dateKey: compactDateKey(h.dateKey),
      dateKeyJSON: canonicalJSON(h.dateKey) ?? '',
      network: h.dateKey.profileId,
      round: h.dateKey.round,
    };
    out.extensions = [
      ...h.critical.map((e) => extensionRow(e, true, r.unusableExtensions, input.extensions)),
      ...h.noncritical.map((e) => extensionRow(e, false, r.unusableExtensions, input.extensions)),
    ];
  }

  const p = r.profile;
  if (p !== undefined) {
    out.profile = {
      id: p.id,
      provider: p.provider,
      network: p.network,
      chainHash: chainHashHex(p),
      period: p.period,
      genesis: formatRFC3339({ seconds: p.genesisTime, nanos: 0 }),
      scheme: p.scheme,
    };
  }

  if (r.unlockAt !== undefined) {
    out.unlock = { rfc3339: formatRFC3339(r.unlockAt), epochMs: instantToEpochMs(r.unlockAt) };
  }
  if (r.outerStanzas !== undefined) out.outerStanzas = r.outerStanzas;
  if (r.payloadStanzas !== undefined) out.payloadStanzas = r.payloadStanzas;

  if (r.outerStanzas !== undefined && h !== undefined && p !== undefined) {
    const t = r.outerStanzas.find((s) => s.type === STANZA_TLOCK);
    if (t !== undefined) {
      out.tlock = [
        compare('Argumentos', String(t.args.length), '2'),
        compare('Ronda', t.args[0], String(h.dateKey.round)),
        compare('Cadena (chain hash)', t.args[1], chainHashHex(p)),
      ];
    }
  }
  if (r.publicNote !== undefined) out.note = { text: r.publicNote };
  else if (r.unusableNote === true) out.note = { unusable: true };
  return out;
}

function compare(label: string, found: string | undefined, expected: string): Comparison {
  return { label, found, expected, match: found === expected };
}

function steps(r: Inspection): StepRow[] {
  return INSPECT_STEPS.map((step): StepRow => {
    const c = r.checks.find((x) => x.step === step);
    const base = { step, name: stepName(step), gloss: stepGloss(step) };
    if (c === undefined) return { ...base, state: 'not-run' };
    if (c.ok) return c.detail === undefined ? { ...base, state: 'ok' } : { ...base, state: 'ok', detail: c.detail };
    const failed: { -readonly [K in keyof StepRow]: StepRow[K] } = { ...base, state: 'failed' };
    if (c.detail !== undefined) failed.detail = c.detail;
    if (r.error !== undefined) failed.code = r.error.code;
    return failed;
  });
}

/**
 * The row of one extension of PUBLIC_HEADER, CONTROL_CBOR or a .dkk, given
 * the known noncritical extensions of that object that the registry rejects.
 */
export function extensionRow(e: Extension, critical: boolean, unusable: readonly Unusable[], reg: ExtensionRegistry | undefined): ExtensionRow {
  const id = displayText(e.id);
  const row: { -readonly [K in keyof ExtensionRow]: ExtensionRow[K] } = {
    critical,
    id: id.text,
    idEscaped: id.escaped,
    version: e.version,
    known: reg?.known(e.id, e.version) ?? false,
    length: e.data?.length ?? 0,
    hex: e.data === undefined ? '' : toHex(e.data),
  };
  const u = critical ? undefined : unusable.find((x) => x.id === e.id && x.version === e.version);
  if (u !== undefined) row.unusable = u.error.message;
  if (e.data !== undefined) {
    const text = printableText(e.data);
    if (text !== undefined) row.text = text;
    const cbor = cborView(e.data);
    if (cbor !== undefined) row.cbor = cbor;
  }
  return row;
}