“use strict”;

Object.defineProperty(exports, “__esModule”, {

value: true

}); exports.default = void 0;

var _helperPluginUtils = require(“@babel/helper-plugin-utils”);

var _tdz = require(“./tdz”);

var _values = _interopRequireDefault(require(“lodash/values”));

var _extend = _interopRequireDefault(require(“lodash/extend”));

var _core = require(“@babel/core”);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

const DONE = new WeakSet();

var _default = (0, _helperPluginUtils.declare)((api, opts) => {

api.assertVersion(7);
const {
  throwIfClosureRequired = false,
  tdz: tdzEnabled = false
} = opts;

if (typeof throwIfClosureRequired !== "boolean") {
  throw new Error(`.throwIfClosureRequired must be a boolean, or undefined`);
}

if (typeof tdzEnabled !== "boolean") {
  throw new Error(`.tdz must be a boolean, or undefined`);
}

return {
  name: "transform-block-scoping",
  visitor: {
    VariableDeclaration(path) {
      const {
        node,
        parent,
        scope
      } = path;
      if (!isBlockScoped(node)) return;
      convertBlockScopedToVar(path, null, parent, scope, true);

      if (node._tdzThis) {
        const nodes = [node];

        for (let i = 0; i < node.declarations.length; i++) {
          const decl = node.declarations[i];

          const assign = _core.types.assignmentExpression("=", decl.id, decl.init || scope.buildUndefinedNode());

          assign._ignoreBlockScopingTDZ = true;
          nodes.push(_core.types.expressionStatement(assign));
          decl.init = this.addHelper("temporalUndefined");
        }

        node._blockHoist = 2;

        if (path.isCompletionRecord()) {
          nodes.push(_core.types.expressionStatement(scope.buildUndefinedNode()));
        }

        path.replaceWithMultiple(nodes);
      }
    },

    Loop(path, state) {
      const {
        parent,
        scope
      } = path;
      path.ensureBlock();
      const blockScoping = new BlockScoping(path, path.get("body"), parent, scope, throwIfClosureRequired, tdzEnabled, state);
      const replace = blockScoping.run();
      if (replace) path.replaceWith(replace);
    },

    CatchClause(path, state) {
      const {
        parent,
        scope
      } = path;
      const blockScoping = new BlockScoping(null, path.get("body"), parent, scope, throwIfClosureRequired, tdzEnabled, state);
      blockScoping.run();
    },

    "BlockStatement|SwitchStatement|Program"(path, state) {
      if (!ignoreBlock(path)) {
        const blockScoping = new BlockScoping(null, path, path.parent, path.scope, throwIfClosureRequired, tdzEnabled, state);
        blockScoping.run();
      }
    }

  }
};

});

exports.default = _default;

function ignoreBlock(path) {

return _core.types.isLoop(path.parent) || _core.types.isCatchClause(path.parent);

}

const buildRetCheck = (0, _core.template)(`

if (typeof RETURN === "object") return RETURN.v;

`);

function isBlockScoped(node) {

if (!_core.types.isVariableDeclaration(node)) return false;
if (node[_core.types.BLOCK_SCOPED_SYMBOL]) return true;
if (node.kind !== "let" && node.kind !== "const") return false;
return true;

}

function isInLoop(path) {

const loopOrFunctionParent = path.find(path => path.isLoop() || path.isFunction());
return loopOrFunctionParent && loopOrFunctionParent.isLoop();

}

function convertBlockScopedToVar(path, node, parent, scope, moveBindingsToParent = false) {

if (!node) {
  node = path.node;
}

if (isInLoop(path) && !_core.types.isFor(parent)) {
  for (let i = 0; i < node.declarations.length; i++) {
    const declar = node.declarations[i];
    declar.init = declar.init || scope.buildUndefinedNode();
  }
}

node[_core.types.BLOCK_SCOPED_SYMBOL] = true;
node.kind = "var";

if (moveBindingsToParent) {
  const parentScope = scope.getFunctionParent() || scope.getProgramParent();

  for (const name of Object.keys(path.getBindingIdentifiers())) {
    const binding = scope.getOwnBinding(name);
    if (binding) binding.kind = "var";
    scope.moveBindingTo(name, parentScope);
  }
}

}

function isVar(node) {

return _core.types.isVariableDeclaration(node, {
  kind: "var"
}) && !isBlockScoped(node);

}

const letReferenceBlockVisitor = _core.traverse.visitors.merge([{

Loop: {
  enter(path, state) {
    state.loopDepth++;
  },

  exit(path, state) {
    state.loopDepth--;
  }

},

Function(path, state) {
  if (state.loopDepth > 0) {
    path.traverse(letReferenceFunctionVisitor, state);
  } else {
    path.traverse(_tdz.visitor, state);
  }

  return path.skip();
}

}, _tdz.visitor]);

const letReferenceFunctionVisitor = _core.traverse.visitors.merge([{

ReferencedIdentifier(path, state) {
  const ref = state.letReferences[path.node.name];
  if (!ref) return;
  const localBinding = path.scope.getBindingIdentifier(path.node.name);
  if (localBinding && localBinding !== ref) return;
  state.closurify = true;
}

}, _tdz.visitor]);

const hoistVarDeclarationsVisitor = {

enter(path, self) {
  const {
    node,
    parent
  } = path;

  if (path.isForStatement()) {
    if (isVar(node.init, node)) {
      const nodes = self.pushDeclar(node.init);

      if (nodes.length === 1) {
        node.init = nodes[0];
      } else {
        node.init = _core.types.sequenceExpression(nodes);
      }
    }
  } else if (path.isFor()) {
    if (isVar(node.left, node)) {
      self.pushDeclar(node.left);
      node.left = node.left.declarations[0].id;
    }
  } else if (isVar(node, parent)) {
    path.replaceWithMultiple(self.pushDeclar(node).map(expr => _core.types.expressionStatement(expr)));
  } else if (path.isFunction()) {
    return path.skip();
  }
}

}; const loopLabelVisitor = {

LabeledStatement({
  node
}, state) {
  state.innerLabels.push(node.label.name);
}

}; const continuationVisitor = {

enter(path, state) {
  if (path.isAssignmentExpression() || path.isUpdateExpression()) {
    for (const name of Object.keys(path.getBindingIdentifiers())) {
      if (state.outsideReferences[name] !== path.scope.getBindingIdentifier(name)) {
        continue;
      }

      state.reassignments[name] = true;
    }
  } else if (path.isReturnStatement()) {
    state.returnStatements.push(path);
  }
}

};

function loopNodeTo(node) {

if (_core.types.isBreakStatement(node)) {
  return "break";
} else if (_core.types.isContinueStatement(node)) {
  return "continue";
}

}

const loopVisitor = {

Loop(path, state) {
  const oldIgnoreLabeless = state.ignoreLabeless;
  state.ignoreLabeless = true;
  path.traverse(loopVisitor, state);
  state.ignoreLabeless = oldIgnoreLabeless;
  path.skip();
},

Function(path) {
  path.skip();
},

SwitchCase(path, state) {
  const oldInSwitchCase = state.inSwitchCase;
  state.inSwitchCase = true;
  path.traverse(loopVisitor, state);
  state.inSwitchCase = oldInSwitchCase;
  path.skip();
},

"BreakStatement|ContinueStatement|ReturnStatement"(path, state) {
  const {
    node,
    scope
  } = path;
  if (node[this.LOOP_IGNORE]) return;
  let replace;
  let loopText = loopNodeTo(node);

  if (loopText) {
    if (node.label) {
      if (state.innerLabels.indexOf(node.label.name) >= 0) {
        return;
      }

      loopText = `${loopText}|${node.label.name}`;
    } else {
      if (state.ignoreLabeless) return;
      if (_core.types.isBreakStatement(node) && state.inSwitchCase) return;
    }

    state.hasBreakContinue = true;
    state.map[loopText] = node;
    replace = _core.types.stringLiteral(loopText);
  }

  if (path.isReturnStatement()) {
    state.hasReturn = true;
    replace = _core.types.objectExpression([_core.types.objectProperty(_core.types.identifier("v"), node.argument || scope.buildUndefinedNode())]);
  }

  if (replace) {
    replace = _core.types.returnStatement(replace);
    replace[this.LOOP_IGNORE] = true;
    path.skip();
    path.replaceWith(_core.types.inherits(replace, node));
  }
}

};

class BlockScoping {

constructor(loopPath, blockPath, parent, scope, throwIfClosureRequired, tdzEnabled, state) {
  this.parent = parent;
  this.scope = scope;
  this.state = state;
  this.throwIfClosureRequired = throwIfClosureRequired;
  this.tdzEnabled = tdzEnabled;
  this.blockPath = blockPath;
  this.block = blockPath.node;
  this.outsideLetReferences = Object.create(null);
  this.hasLetReferences = false;
  this.letReferences = Object.create(null);
  this.body = [];

  if (loopPath) {
    this.loopParent = loopPath.parent;
    this.loopLabel = _core.types.isLabeledStatement(this.loopParent) && this.loopParent.label;
    this.loopPath = loopPath;
    this.loop = loopPath.node;
  }
}

run() {
  const block = this.block;
  if (DONE.has(block)) return;
  DONE.add(block);
  const needsClosure = this.getLetReferences();
  this.checkConstants();

  if (_core.types.isFunction(this.parent) || _core.types.isProgram(this.block)) {
    this.updateScopeInfo();
    return;
  }

  if (!this.hasLetReferences) return;

  if (needsClosure) {
    this.wrapClosure();
  } else {
    this.remap();
  }

  this.updateScopeInfo(needsClosure);

  if (this.loopLabel && !_core.types.isLabeledStatement(this.loopParent)) {
    return _core.types.labeledStatement(this.loopLabel, this.loop);
  }
}

checkConstants() {
  const scope = this.scope;
  const state = this.state;

  for (const name of Object.keys(scope.bindings)) {
    const binding = scope.bindings[name];
    if (binding.kind !== "const") continue;

    for (const violation of binding.constantViolations) {
      const readOnlyError = state.addHelper("readOnlyError");

      const throwNode = _core.types.callExpression(readOnlyError, [_core.types.stringLiteral(name)]);

      if (violation.isAssignmentExpression()) {
        violation.get("right").replaceWith(_core.types.sequenceExpression([throwNode, violation.get("right").node]));
      } else if (violation.isUpdateExpression()) {
        violation.replaceWith(_core.types.sequenceExpression([throwNode, violation.node]));
      } else if (violation.isForXStatement()) {
        violation.ensureBlock();
        violation.node.body.body.unshift(_core.types.expressionStatement(throwNode));
      }
    }
  }
}

updateScopeInfo(wrappedInClosure) {
  const blockScope = this.blockPath.scope;
  const parentScope = blockScope.getFunctionParent() || blockScope.getProgramParent();
  const letRefs = this.letReferences;

  for (const key of Object.keys(letRefs)) {
    const ref = letRefs[key];
    const binding = blockScope.getBinding(ref.name);
    if (!binding) continue;

    if (binding.kind === "let" || binding.kind === "const") {
      binding.kind = "var";

      if (wrappedInClosure) {
        if (blockScope.hasOwnBinding(ref.name)) {
          blockScope.removeBinding(ref.name);
        }
      } else {
        blockScope.moveBindingTo(ref.name, parentScope);
      }
    }
  }
}

remap() {
  const letRefs = this.letReferences;
  const outsideLetRefs = this.outsideLetReferences;
  const scope = this.scope;
  const blockPathScope = this.blockPath.scope;

  for (const key of Object.keys(letRefs)) {
    const ref = letRefs[key];

    if (scope.parentHasBinding(key) || scope.hasGlobal(key)) {
      if (scope.hasOwnBinding(key)) {
        scope.rename(ref.name);
      }

      if (blockPathScope.hasOwnBinding(key)) {
        blockPathScope.rename(ref.name);
      }
    }
  }

  for (const key of Object.keys(outsideLetRefs)) {
    const ref = letRefs[key];

    if (isInLoop(this.blockPath) && blockPathScope.hasOwnBinding(key)) {
      blockPathScope.rename(ref.name);
    }
  }
}

wrapClosure() {
  if (this.throwIfClosureRequired) {
    throw this.blockPath.buildCodeFrameError("Compiling let/const in this block would add a closure " + "(throwIfClosureRequired).");
  }

  const block = this.block;
  const outsideRefs = this.outsideLetReferences;

  if (this.loop) {
    for (const name of Object.keys(outsideRefs)) {
      const id = outsideRefs[name];

      if (this.scope.hasGlobal(id.name) || this.scope.parentHasBinding(id.name)) {
        delete outsideRefs[id.name];
        delete this.letReferences[id.name];
        this.scope.rename(id.name);
        this.letReferences[id.name] = id;
        outsideRefs[id.name] = id;
      }
    }
  }

  this.has = this.checkLoop();
  this.hoistVarDeclarations();
  const args = (0, _values.default)(outsideRefs).map(id => _core.types.cloneNode(id));
  const params = args.map(id => _core.types.cloneNode(id));
  const isSwitch = this.blockPath.isSwitchStatement();

  const fn = _core.types.functionExpression(null, params, _core.types.blockStatement(isSwitch ? [block] : block.body));

  this.addContinuations(fn);

  let call = _core.types.callExpression(_core.types.nullLiteral(), args);

  let basePath = ".callee";

  const hasYield = _core.traverse.hasType(fn.body, "YieldExpression", _core.types.FUNCTION_TYPES);

  if (hasYield) {
    fn.generator = true;
    call = _core.types.yieldExpression(call, true);
    basePath = ".argument" + basePath;
  }

  const hasAsync = _core.traverse.hasType(fn.body, "AwaitExpression", _core.types.FUNCTION_TYPES);

  if (hasAsync) {
    fn.async = true;
    call = _core.types.awaitExpression(call);
    basePath = ".argument" + basePath;
  }

  let placeholderPath;
  let index;

  if (this.has.hasReturn || this.has.hasBreakContinue) {
    const ret = this.scope.generateUid("ret");
    this.body.push(_core.types.variableDeclaration("var", [_core.types.variableDeclarator(_core.types.identifier(ret), call)]));
    placeholderPath = "declarations.0.init" + basePath;
    index = this.body.length - 1;
    this.buildHas(ret);
  } else {
    this.body.push(_core.types.expressionStatement(call));
    placeholderPath = "expression" + basePath;
    index = this.body.length - 1;
  }

  let callPath;

  if (isSwitch) {
    const {
      parentPath,
      listKey,
      key
    } = this.blockPath;
    this.blockPath.replaceWithMultiple(this.body);
    callPath = parentPath.get(listKey)[key + index];
  } else {
    block.body = this.body;
    callPath = this.blockPath.get("body")[index];
  }

  const placeholder = callPath.get(placeholderPath);
  let fnPath;

  if (this.loop) {
    const loopId = this.scope.generateUid("loop");
    const p = this.loopPath.insertBefore(_core.types.variableDeclaration("var", [_core.types.variableDeclarator(_core.types.identifier(loopId), fn)]));
    placeholder.replaceWith(_core.types.identifier(loopId));
    fnPath = p[0].get("declarations.0.init");
  } else {
    placeholder.replaceWith(fn);
    fnPath = placeholder;
  }

  fnPath.unwrapFunctionEnvironment();
}

addContinuations(fn) {
  const state = {
    reassignments: {},
    returnStatements: [],
    outsideReferences: this.outsideLetReferences
  };
  this.scope.traverse(fn, continuationVisitor, state);

  for (let i = 0; i < fn.params.length; i++) {
    const param = fn.params[i];
    if (!state.reassignments[param.name]) continue;
    const paramName = param.name;
    const newParamName = this.scope.generateUid(param.name);
    fn.params[i] = _core.types.identifier(newParamName);
    this.scope.rename(paramName, newParamName, fn);
    state.returnStatements.forEach(returnStatement => {
      returnStatement.insertBefore(_core.types.expressionStatement(_core.types.assignmentExpression("=", _core.types.identifier(paramName), _core.types.identifier(newParamName))));
    });
    fn.body.body.push(_core.types.expressionStatement(_core.types.assignmentExpression("=", _core.types.identifier(paramName), _core.types.identifier(newParamName))));
  }
}

getLetReferences() {
  const block = this.block;
  let declarators = [];

  if (this.loop) {
    const init = this.loop.left || this.loop.init;

    if (isBlockScoped(init)) {
      declarators.push(init);
      (0, _extend.default)(this.outsideLetReferences, _core.types.getBindingIdentifiers(init));
    }
  }

  const addDeclarationsFromChild = (path, node) => {
    node = node || path.node;

    if (_core.types.isClassDeclaration(node) || _core.types.isFunctionDeclaration(node) || isBlockScoped(node)) {
      if (isBlockScoped(node)) {
        convertBlockScopedToVar(path, node, block, this.scope);
      }

      declarators = declarators.concat(node.declarations || node);
    }

    if (_core.types.isLabeledStatement(node)) {
      addDeclarationsFromChild(path.get("body"), node.body);
    }
  };

  if (block.body) {
    const declarPaths = this.blockPath.get("body");

    for (let i = 0; i < block.body.length; i++) {
      addDeclarationsFromChild(declarPaths[i]);
    }
  }

  if (block.cases) {
    const declarPaths = this.blockPath.get("cases");

    for (let i = 0; i < block.cases.length; i++) {
      const consequents = block.cases[i].consequent;

      for (let j = 0; j < consequents.length; j++) {
        const declar = consequents[j];
        addDeclarationsFromChild(declarPaths[i], declar);
      }
    }
  }

  for (let i = 0; i < declarators.length; i++) {
    const declar = declarators[i];

    const keys = _core.types.getBindingIdentifiers(declar, false, true);

    (0, _extend.default)(this.letReferences, keys);
    this.hasLetReferences = true;
  }

  if (!this.hasLetReferences) return;
  const state = {
    letReferences: this.letReferences,
    closurify: false,
    loopDepth: 0,
    tdzEnabled: this.tdzEnabled,
    addHelper: name => this.state.addHelper(name)
  };

  if (isInLoop(this.blockPath)) {
    state.loopDepth++;
  }

  this.blockPath.traverse(letReferenceBlockVisitor, state);
  return state.closurify;
}

checkLoop() {
  const state = {
    hasBreakContinue: false,
    ignoreLabeless: false,
    inSwitchCase: false,
    innerLabels: [],
    hasReturn: false,
    isLoop: !!this.loop,
    map: {},
    LOOP_IGNORE: Symbol()
  };
  this.blockPath.traverse(loopLabelVisitor, state);
  this.blockPath.traverse(loopVisitor, state);
  return state;
}

hoistVarDeclarations() {
  this.blockPath.traverse(hoistVarDeclarationsVisitor, this);
}

pushDeclar(node) {
  const declars = [];

  const names = _core.types.getBindingIdentifiers(node);

  for (const name of Object.keys(names)) {
    declars.push(_core.types.variableDeclarator(names[name]));
  }

  this.body.push(_core.types.variableDeclaration(node.kind, declars));
  const replace = [];

  for (let i = 0; i < node.declarations.length; i++) {
    const declar = node.declarations[i];
    if (!declar.init) continue;

    const expr = _core.types.assignmentExpression("=", _core.types.cloneNode(declar.id), _core.types.cloneNode(declar.init));

    replace.push(_core.types.inherits(expr, declar));
  }

  return replace;
}

buildHas(ret) {
  const body = this.body;
  let retCheck;
  const has = this.has;
  const cases = [];

  if (has.hasReturn) {
    retCheck = buildRetCheck({
      RETURN: _core.types.identifier(ret)
    });
  }

  if (has.hasBreakContinue) {
    for (const key of Object.keys(has.map)) {
      cases.push(_core.types.switchCase(_core.types.stringLiteral(key), [has.map[key]]));
    }

    if (has.hasReturn) {
      cases.push(_core.types.switchCase(null, [retCheck]));
    }

    if (cases.length === 1) {
      const single = cases[0];
      body.push(_core.types.ifStatement(_core.types.binaryExpression("===", _core.types.identifier(ret), single.test), single.consequent[0]));
    } else {
      if (this.loop) {
        for (let i = 0; i < cases.length; i++) {
          const caseConsequent = cases[i].consequent[0];

          if (_core.types.isBreakStatement(caseConsequent) && !caseConsequent.label) {
            if (!this.loopLabel) {
              this.loopLabel = this.scope.generateUidIdentifier("loop");
            }

            caseConsequent.label = _core.types.cloneNode(this.loopLabel);
          }
        }
      }

      body.push(_core.types.switchStatement(_core.types.identifier(ret), cases));
    }
  } else {
    if (has.hasReturn) {
      body.push(retCheck);
    }
  }
}

}