import * as t from "@babel/types";

import {
  compareUnicodeCodePoints,
  compositeKey,
} from "../unicodeCodePointOrder.js";
import { stripQueryAndFragment } from "../artifactPathSyntax.js";
import type { ElectronNativeAddonBindingFinding } from "./electronStaticAnalysisTypes.js";
import {
  isTypeOnlyExportDeclaration,
  isTypeOnlyExportSpecifier,
  isTypeOnlyImportDeclaration,
  isTypeOnlyImportSpecifier,
} from "./javascriptModuleDeclaration.js";
import { addLocatedFinding } from "./javascriptStaticAnalysisFindings.js";
import {
  argumentNode,
  range,
  stringValue,
} from "./javascriptStaticAnalysisHelpers.js";
import {
  propertyName,
  semanticStaticPropertyKey,
  unwrapJavaScriptExpression,
} from "./javascriptAstValues.js";
import { semanticRequireCallAt } from "./javascriptSemanticRequireOrigin.js";
import {
  commonJsExportApplicability,
  commonJsRuntimeExportValues,
  indexCommonJsExportReceiversSteps,
  type CommonJsExportReceiverEffect,
  type CommonJsExportSite,
} from "./javascriptCommonJsExportReceivers.js";
import type { JavaScriptReceiverIndex } from "./javascriptSemanticAnalysis.js";
import type { JavaScriptSemanticAnalysisState } from "./javascriptSemanticState.js";
import type { JavaScriptFindingContext } from "./javascriptStaticAnalysisState.js";

interface NativeBindingInput {
  readonly context: JavaScriptFindingContext;
  readonly node: t.Node;
  readonly specifier: string;
  readonly kind: ElectronNativeAddonBindingFinding["binding_kind"];
  readonly moduleKind: ElectronNativeAddonBindingFinding["module_kind"];
  readonly members: readonly string[];
  readonly namespaceAccess: boolean;
  readonly dynamicMemberAccess: boolean;
}

/** Inspect JavaScript-side imports and re-exports of native .node addons. */
export const inspectElectronNativeNode = (
  node: t.Node,
  context: JavaScriptFindingContext,
): void => {
  if (t.isImportDeclaration(node)) inspectImport(node, context);
  else if (t.isExportNamedDeclaration(node)) inspectNamedExport(node, context);
  else if (t.isExportAllDeclaration(node)) inspectExportAll(node, context);
  else if (t.isVariableDeclarator(node) || t.isAssignmentExpression(node)) {
    const value = nativeCallReceiver(
      t.isVariableDeclarator(node) ? node.init : node.right,
    );
    // Admission is syntax only; the shared call owner proves loader and arguments later.
    if (
      value !== undefined &&
      value.arguments.some((argument) =>
        t.isArrayExpression(argument)
          ? argument.elements.some((element) =>
              isNativeSpecifier(stringValue(element) ?? "", "require"),
            )
          : isNativeSpecifier(stringValue(argument) ?? "", "require"),
      )
    )
      context.accumulator.pendingNativeAddonBindings.push(node);
  }
};

/** Shared loader, argument and receiver facts settle before native projection. */
export function* finishElectronNativeBindingsSteps(
  context: JavaScriptFindingContext,
  index: JavaScriptReceiverIndex,
): Generator<void, void> {
  const pending = context.accumulator.pendingNativeAddonBindings;
  if (pending.length === 0) return;
  yield* index.indexMemberMutationFactsSteps();
  const receivers = pending.some((node) => t.isAssignmentExpression(node))
    ? yield* indexCommonJsExportReceiversSteps(index.bindings)
    : new Map<CommonJsExportSite, CommonJsExportReceiverEffect>();
  for (const node of pending) {
    if (t.isVariableDeclarator(node))
      inspectRequireBinding(node, context, index.bindings);
    else inspectReExport(node, context, index.bindings, receivers.get(node));
  }
  pending.length = 0;
}

const inspectImport = (
  node: t.ImportDeclaration,
  context: JavaScriptFindingContext,
): void => {
  if (!isNativeSpecifier(node.source.value, "import")) return;
  // TypeScript erases `import type` and per-binding `type` imports; they never
  // request a runtime native-addon member.
  if (isTypeOnlyImportDeclaration(node)) return;
  const valueSpecifiers = node.specifiers.filter(
    (specifier) =>
      !(t.isImportSpecifier(specifier) && isTypeOnlyImportSpecifier(specifier)),
  );
  if (node.specifiers.length > 0 && valueSpecifiers.length === 0) return;
  const members = valueSpecifiers.flatMap((specifier) => {
    if (t.isImportDefaultSpecifier(specifier)) return ["default"];
    if (t.isImportNamespaceSpecifier(specifier)) return [];
    return [propertyName(specifier.imported)];
  });
  addBinding({
    context,
    node,
    specifier: node.source.value,
    kind: "import",
    moduleKind: "import",
    members,
    namespaceAccess: valueSpecifiers.some((value) =>
      t.isImportNamespaceSpecifier(value),
    ),
    dynamicMemberAccess: false,
  });
};

const inspectNamedExport = (
  node: t.ExportNamedDeclaration,
  context: JavaScriptFindingContext,
): void => {
  if (
    node.source === null ||
    node.source === undefined ||
    !isNativeSpecifier(node.source.value, "import")
  )
    return;
  if (isTypeOnlyExportDeclaration(node)) return;
  const valueSpecifiers = node.specifiers.filter(
    (specifier) =>
      !(t.isExportSpecifier(specifier) && isTypeOnlyExportSpecifier(specifier)),
  );
  if (node.specifiers.length > 0 && valueSpecifiers.length === 0) return;
  const members = valueSpecifiers.flatMap((specifier) => {
    if (t.isExportSpecifier(specifier)) return [propertyName(specifier.local)];
    if (t.isExportDefaultSpecifier(specifier)) return ["default"];
    return [];
  });
  addBinding({
    context,
    node,
    specifier: node.source.value,
    kind: "re-export",
    moduleKind: "import",
    members,
    namespaceAccess: valueSpecifiers.some((value) =>
      t.isExportNamespaceSpecifier(value),
    ),
    dynamicMemberAccess: false,
  });
};

const inspectExportAll = (
  node: t.ExportAllDeclaration,
  context: JavaScriptFindingContext,
): void => {
  if (
    node.source === undefined ||
    !isNativeSpecifier(node.source.value, "import") ||
    isTypeOnlyExportDeclaration(node)
  )
    return;
  addBinding({
    context,
    node,
    specifier: node.source.value,
    kind: "re-export",
    moduleKind: "import",
    members: [],
    namespaceAccess: true,
    dynamicMemberAccess: false,
  });
};

const inspectRequireBinding = (
  node: t.VariableDeclarator,
  context: JavaScriptFindingContext,
  bindings: JavaScriptSemanticAnalysisState,
): void => {
  const required = nativeRequire(node.init, context, bindings);
  if (required === undefined) return;
  addBinding({
    context,
    node,
    specifier: required.specifier,
    kind: "require",
    moduleKind: "require",
    ...(required.hasMemberAccess ? required.access : bindingMembers(node.id)),
  });
};

const inspectReExport = (
  node: t.AssignmentExpression,
  context: JavaScriptFindingContext,
  bindings: JavaScriptSemanticAnalysisState,
  receiver: CommonJsExportReceiverEffect | undefined,
): void => {
  const exported = commonJsRuntimeExportValues(node, bindings)[0];
  if (exported === undefined) return;
  const applicability = commonJsExportApplicability(
    receiver,
    exported.exportedName,
  );
  if (applicability === "detached") return;
  if (applicability === "uncertain") {
    context.accumulator.unknownFindings += 1;
    return;
  }
  // The export owner leaves arithmetic/logical stores without a selected RHS.
  const value = exported.value;
  if (value == null) return;
  const required = nativeRequire(value, context, bindings);
  if (required === undefined) return;
  addBinding({
    context,
    node,
    specifier: required.specifier,
    kind: "re-export",
    moduleKind: "require",
    ...required.access,
  });
};

const addBinding = (input: NativeBindingInput): void => {
  const { context, node, specifier, kind } = input;
  const members = [...new Set(input.members)].sort(compareUnicodeCodePoints);
  addLocatedFinding(context, {
    collection: context.accumulator.nativeAddonBindings,
    // Members are a variable-length source-derived list: compositeKey keeps
    // ["a\0b"] distinct from ["a", "b"] instead of collapsing one binding.
    key: compositeKey([
      "native-addon-binding",
      kind,
      specifier,
      members,
      input.namespaceAccess,
      input.dynamicMemberAccess,
    ]),
    node,
    value: {
      specifier,
      binding_kind: kind,
      module_kind: input.moduleKind,
      members,
      namespace_access: input.namespaceAccess,
      dynamic_member_access: input.dynamicMemberAccess,
      module_key: null,
      location: range(node),
    },
  });
};

const nativeCallReceiver = (
  node: t.Node | null | undefined,
): t.CallExpression | t.OptionalCallExpression | undefined => {
  if (node == null) return undefined;
  node = unwrapJavaScriptExpression(node).node;
  while (t.isMemberExpression(node) || t.isOptionalMemberExpression(node))
    node = unwrapJavaScriptExpression(node.object).node;
  return t.isCallExpression(node) || t.isOptionalCallExpression(node)
    ? node
    : undefined;
};

const nativeRequire = (
  node: t.Node | null | undefined,
  context: JavaScriptFindingContext,
  bindings: JavaScriptSemanticAnalysisState,
):
  | {
      readonly specifier: string;
      readonly hasMemberAccess: boolean;
      readonly access: NativeMemberAccess;
    }
  | undefined => {
  if (node == null) return undefined;
  node = unwrapJavaScriptExpression(node).node;
  let member: string | null = null;
  let hasMemberAccess = false;
  while (t.isMemberExpression(node) || t.isOptionalMemberExpression(node)) {
    if (!t.isNode(node.object)) return undefined;
    const property = semanticStaticPropertyKey(node.property, node.computed);
    // Walking inward leaves the first member consumed from the addon itself.
    member = property;
    hasMemberAccess = true;
    node = unwrapJavaScriptExpression(node.object).node;
  }
  if (!t.isCallExpression(node) && !t.isOptionalCallExpression(node))
    return undefined;
  const call = semanticRequireCallAt(
    node,
    bindings,
    context.accumulator.factoryRequireBindingIds,
  );
  if (
    call === undefined ||
    call.loader === "local" ||
    call.operation !== "load"
  )
    return undefined;
  const specifier = stringValue(argumentNode(call.arguments?.[0]));
  if (specifier === undefined || !isNativeSpecifier(specifier, "require"))
    return undefined;
  if (
    call.loader === "unknown" ||
    !call.sourceRelative ||
    call.sourceRelativePath !== undefined
  ) {
    context.accumulator.unknownFindings += 1;
    return undefined;
  }
  return {
    specifier,
    hasMemberAccess,
    access: {
      members: member === null ? [] : [member],
      namespaceAccess: !hasMemberAccess,
      dynamicMemberAccess: hasMemberAccess && member === null,
    },
  };
};

interface NativeMemberAccess {
  readonly members: readonly string[];
  readonly namespaceAccess: boolean;
  readonly dynamicMemberAccess: boolean;
}

const bindingMembers = (pattern: t.Node): NativeMemberAccess => {
  if (!t.isObjectPattern(pattern))
    return { members: [], namespaceAccess: true, dynamicMemberAccess: false };
  const members: string[] = [];
  let namespaceAccess = false;
  let dynamicMemberAccess = false;
  for (const property of pattern.properties) {
    if (t.isRestElement(property)) {
      namespaceAccess = true;
      continue;
    }
    const key = semanticStaticPropertyKey(property.key, property.computed);
    if (key === null) dynamicMemberAccess = true;
    else members.push(key);
  }
  return { members, namespaceAccess, dynamicMemberAccess };
};

const isNativeSpecifier = (
  specifier: string,
  moduleKind: ElectronNativeAddonBindingFinding["module_kind"],
): boolean => {
  const path =
    moduleKind === "require" ? specifier : stripQueryAndFragment(specifier);
  return path.toLowerCase().endsWith(".node");
};