import {LooseParser} from "./state"
import {isDummy} from "./parseutil"
import {tokTypes as tt} from ".."

const lp = LooseParser.prototype

lp.checkLVal = function(expr) {
  if (!expr) return expr;
  switch (expr.type) {
  case "Identifier":
  case "MemberExpression":
  case "ObjectPattern":
  case "ArrayPattern":
  case "RestElement":
  case "AssignmentPattern":
    return expr;

  default:
    return this.dummyIdent();
  }
};

lp.parseExpression = function(noIn) {
  var start = this.storeCurrentPos();
  var expr = this.parseMaybeAssign(noIn);
  if (this.tok.type === tt.comma) {
    var node = this.startNodeAt(start);
    node.expressions = [expr];
    while (this.eat(tt.comma)) node.expressions.push(this.parseMaybeAssign(noIn));
    return this.finishNode(node, "SequenceExpression");
  }
  return expr;
};

lp.parseParenExpression = function() {
  this.pushCx();
  this.expect(tt.parenL);
  var val = this.parseExpression();
  this.popCx();
  this.expect(tt.parenR);
  return val;
};

lp.parseMaybeAssign = function(noIn) {
  var start = this.storeCurrentPos();
  var left = this.parseMaybeConditional(noIn);
  if (this.tok.type.isAssign) {
    var node = this.startNodeAt(start);
    node.operator = this.tok.value;
    node.left = this.tok.type === tt.eq ? this.toAssignable(left) : this.checkLVal(left);
    this.next();
    node.right = this.parseMaybeAssign(noIn);
    return this.finishNode(node, "AssignmentExpression");
  }
  return left;
};

lp.parseMaybeConditional = function(noIn) {
  var start = this.storeCurrentPos();
  var expr = this.parseExprOps(noIn);
  if (this.eat(tt.question)) {
    var node = this.startNodeAt(start);
    node.test = expr;
    node.consequent = this.parseMaybeAssign();
    node.alternate = this.expect(tt.colon) ? this.parseMaybeAssign(noIn) : this.dummyIdent();
    return this.finishNode(node, "ConditionalExpression");
  }
  return expr;
};

lp.parseExprOps = function(noIn) {
  var start = this.storeCurrentPos();
  var indent = this.curIndent, line = this.curLineStart;
  return this.parseExprOp(this.parseMaybeUnary(noIn), start, -1, noIn, indent, line);
};

lp.parseExprOp = function(left, start, minPrec, noIn, indent, line) {
  if (this.curLineStart != line && this.curIndent < indent && this.tokenStartsLine()) return left;
  var prec = this.tok.type.binop;
  if (prec != null && (!noIn || this.tok.type !== tt._in)) {
    if (prec > minPrec) {
      var node = this.startNodeAt(start);
      node.left = left;
      node.operator = this.tok.value;
      this.next();
      if (this.curLineStart != line && this.curIndent < indent && this.tokenStartsLine()) {
        node.right = this.dummyIdent();
      } else {
        var rightStart = this.storeCurrentPos();
        node.right = this.parseExprOp(this.parseMaybeUnary(noIn), rightStart, prec, noIn, indent, line);
      }
      this.finishNode(node, /&&|\|\|/.test(node.operator) ? "LogicalExpression" : "BinaryExpression");
      return this.parseExprOp(node, start, minPrec, noIn, indent, line);
    }
  }
  return left;
};

lp.parseMaybeUnary = function(noIn) {
  if (this.tok.type.prefix) {
    var node = this.startNode(), update = this.tok.type === tt.incDec;
    node.operator = this.tok.value;
    node.prefix = true;
    this.next();
    node.argument = this.parseMaybeUnary(noIn);
    if (update) node.argument = this.checkLVal(node.argument);
    return this.finishNode(node, update ? "UpdateExpression" : "UnaryExpression");
  } else if (this.tok.type === tt.ellipsis) {
    var node = this.startNode();
    this.next();
    node.argument = this.parseMaybeUnary(noIn);
    return this.finishNode(node, "SpreadElement");
  }
  var start = this.storeCurrentPos();
  var expr = this.parseExprSubscripts();
  while (this.tok.type.postfix && !this.canInsertSemicolon()) {
    var node = this.startNodeAt(start);
    node.operator = this.tok.value;
    node.prefix = false;
    node.argument = this.checkLVal(expr);
    this.next();
    expr = this.finishNode(node, "UpdateExpression");
  }
  return expr;
};

lp.parseExprSubscripts = function() {
  var start = this.storeCurrentPos();
  return this.parseSubscripts(this.parseExprAtom(), start, false, this.curIndent, this.curLineStart);
};

lp.parseSubscripts = function(base, start, noCalls, startIndent, line) {
  for (;;) {
    if (this.curLineStart != line && this.curIndent <= startIndent && this.tokenStartsLine()) {
      if (this.tok.type == tt.dot && this.curIndent == startIndent)
        --startIndent;
      else
        return base;
    }

    if (this.eat(tt.dot)) {
      var node = this.startNodeAt(start);
      node.object = base;
      if (this.curLineStart != line && this.curIndent <= startIndent && this.tokenStartsLine())
        node.property = this.dummyIdent();
      else
        node.property = this.parsePropertyAccessor() || this.dummyIdent();
      node.computed = false;
      base = this.finishNode(node, "MemberExpression");
    } else if (this.tok.type == tt.bracketL) {
      this.pushCx();
      this.next();
      var node = this.startNodeAt(start);
      node.object = base;
      node.property = this.parseExpression();
      node.computed = true;
      this.popCx();
      this.expect(tt.bracketR);
      base = this.finishNode(node, "MemberExpression");
    } else if (!noCalls && this.tok.type == tt.parenL) {
      this.pushCx();
      var node = this.startNodeAt(start);
      node.callee = base;
      node.arguments = this.parseExprList(tt.parenR);
      base = this.finishNode(node, "CallExpression");
    } else if (this.tok.type == tt.backQuote) {
      var node = this.startNodeAt(start);
      node.tag = base;
      node.quasi = this.parseTemplate();
      base = this.finishNode(node, "TaggedTemplateExpression");
    } else {
      return base;
    }
  }
};

lp.parseExprAtom = function() {
  switch (this.tok.type) {
  case tt._this:
  case tt._super:
    var type = this.tok.type === tt._this ? "ThisExpression" : "SuperExpression";
    var node = this.startNode();
    this.next();
    return this.finishNode(node, type);

  case tt.name:
    var start = this.storeCurrentPos();
    var id = this.parseIdent();
    return this.eat(tt.arrow) ? this.parseArrowExpression(this.startNodeAt(start), [id]) : id;

  case tt.regexp:
    var node = this.startNode();
    var val = this.tok.value;
    node.regex = {pattern: val.pattern, flags: val.flags};
    node.value = val.value;
    node.raw = this.input.slice(this.tok.start, this.tok.end);
    this.next();
    return this.finishNode(node, "Literal");

  case tt.num: case tt.string:
    var node = this.startNode();
    node.value = this.tok.value;
    node.raw = this.input.slice(this.tok.start, this.tok.end);
    this.next();
    return this.finishNode(node, "Literal");

  case tt._null: case tt._true: case tt._false:
    var node = this.startNode();
    node.value = this.tok.type === tt._null ? null : this.tok.type === tt._true;
    node.raw = this.tok.type.keyword;
    this.next();
    return this.finishNode(node, "Literal");

  case tt.parenL:
    var start = this.storeCurrentPos();
    this.next();
    var val = this.parseExpression();
    this.expect(tt.parenR);
    if (this.eat(tt.arrow)) {
      return this.parseArrowExpression(this.startNodeAt(start), val.expressions || (isDummy(val) ? [] : [val]));
    }
    if (this.options.preserveParens) {
      var par = this.startNodeAt(start);
      par.expression = val;
      val = this.finishNode(par, "ParenthesizedExpression");
    }
    return val;

  case tt.bracketL:
    var node = this.startNode();
    this.pushCx();
    node.elements = this.parseExprList(tt.bracketR, true);
    return this.finishNode(node, "ArrayExpression");

  case tt.braceL:
    return this.parseObj();

  case tt._class:
    return this.parseClass();

  case tt._function:
    var node = this.startNode();
    this.next();
    return this.parseFunction(node, false);

  case tt._new:
    return this.parseNew();

  case tt._yield:
    var node = this.startNode();
    this.next();
    if (this.semicolon() || this.canInsertSemicolon() || (this.tok.type != tt.star && !this.tok.type.startsExpr)) {
      node.delegate = false;
      node.argument = null;
    } else {
      node.delegate = this.eat(tt.star);
      node.argument = this.parseMaybeAssign();
    }
    return this.finishNode(node, "YieldExpression");

  case tt.backQuote:
    return this.parseTemplate();

  default:
    return this.dummyIdent();
  }
};

lp.parseNew = function() {
  var node = this.startNode(), startIndent = this.curIndent, line = this.curLineStart;
  this.next();
  var start = this.storeCurrentPos();
  node.callee = this.parseSubscripts(this.parseExprAtom(), start, true, startIndent, line);
  if (this.tok.type == tt.parenL) {
    this.pushCx();
    node.arguments = this.parseExprList(tt.parenR);
  } else {
    node.arguments = [];
  }
  return this.finishNode(node, "NewExpression");
};

lp.parseTemplateElement = function() {
  var elem = this.startNode();
  elem.value = {
    raw: this.input.slice(this.tok.start, this.tok.end),
    cooked: this.tok.value
  };
  this.next();
  elem.tail = this.tok.type === tt.backQuote;
  return this.finishNode(elem, "TemplateElement");
};

lp.parseTemplate = function() {
  var node = this.startNode();
  this.next();
  node.expressions = [];
  var curElt = this.parseTemplateElement();
  node.quasis = [curElt];
  while (!curElt.tail) {
    this.next();
    node.expressions.push(this.parseExpression());
    if (this.expect(tt.braceR)) {
      curElt = this.parseTemplateElement();
    } else {
      curElt = this.startNode();
      curElt.value = {cooked: '', raw: ''};
      curElt.tail = true;
    }
    node.quasis.push(curElt);
  }
  this.expect(tt.backQuote);
  return this.finishNode(node, "TemplateLiteral");
};

lp.parseObj = function() {
  var node = this.startNode();
  node.properties = [];
  this.pushCx();
  var indent = this.curIndent + 1, line = this.curLineStart;
  this.eat(tt.braceL);
  if (this.curIndent + 1 < indent) { indent = this.curIndent; line = this.curLineStart; }
  while (!this.closes(tt.braceR, indent, line)) {
    var prop = this.startNode(), isGenerator, start;
    if (this.options.ecmaVersion >= 6) {
      start = this.storeCurrentPos();
      prop.method = false;
      prop.shorthand = false;
      isGenerator = this.eat(tt.star);
    }
    this.parsePropertyName(prop);
    if (isDummy(prop.key)) { if (isDummy(this.parseMaybeAssign())) this.next(); this.eat(tt.comma); continue; }
    if (this.eat(tt.colon)) {
      prop.kind = "init";
      prop.value = this.parseMaybeAssign();
    } else if (this.options.ecmaVersion >= 6 && (this.tok.type === tt.parenL || this.tok.type === tt.braceL)) {
      prop.kind = "init";
      prop.method = true;
      prop.value = this.parseMethod(isGenerator);
    } else if (this.options.ecmaVersion >= 5 && prop.key.type === "Identifier" &&
               !prop.computed && (prop.key.name === "get" || prop.key.name === "set") &&
               (this.tok.type != tt.comma && this.tok.type != tt.braceR)) {
      prop.kind = prop.key.name;
      this.parsePropertyName(prop);
      prop.value = this.parseMethod(false);
    } else {
      prop.kind = "init";
      if (this.options.ecmaVersion >= 6) {
        if (this.eat(tt.eq)) {
          var assign = this.startNodeAt(start);
          assign.operator = "=";
          assign.left = prop.key;
          assign.right = this.parseMaybeAssign();
          prop.value = this.finishNode(assign, "AssignmentExpression");
        } else {
          prop.value = prop.key;
        }
      } else {
        prop.value = this.dummyIdent();
      }
      prop.shorthand = true;
    }
    node.properties.push(this.finishNode(prop, "Property"));
    this.eat(tt.comma);
  }
  this.popCx();
  if (!this.eat(tt.braceR)) {
    // If there is no closing brace, make the node span to the start
    // of the next token (this is useful for Tern)
    this.last.end = this.tok.start;
    if (this.options.locations) this.last.loc.end = this.tok.loc.start;
  }
  return this.finishNode(node, "ObjectExpression");
};

lp.parsePropertyName = function(prop) {
  if (this.options.ecmaVersion >= 6) {
    if (this.eat(tt.bracketL)) {
      prop.computed = true;
      prop.key = this.parseExpression();
      this.expect(tt.bracketR);
      return;
    } else {
      prop.computed = false;
    }
  }
  var key = (this.tok.type === tt.num || this.tok.type === tt.string) ? this.parseExprAtom() : this.parseIdent();
  prop.key = key || this.dummyIdent();
};

lp.parsePropertyAccessor = function() {
  if (this.tok.type === tt.name || this.tok.type.keyword) return this.parseIdent();
};

lp.parseIdent = function() {
  var node = this.startNode();
  node.name = this.tok.type === tt.name ? this.tok.value : this.tok.type.keyword;
  this.next();
  return this.finishNode(node, "Identifier");
};

lp.initFunction = function(node) {
  node.id = null;
  node.params = [];
  if (this.options.ecmaVersion >= 6) {
    node.generator = false;
    node.expression = false;
  }
};

// Convert existing expression atom to assignable pattern
// if possible.

lp.toAssignable = function(node) {
  if (this.options.ecmaVersion >= 6 && node) {
    switch (node.type) {
    case "ObjectExpression":
      node.type = "ObjectPattern";
      var props = node.properties;
      for (var i = 0; i < props.length; i++)
        this.toAssignable(props[i].value);
      break;

    case "ArrayExpression":
      node.type = "ArrayPattern";
      this.toAssignableList(node.elements);
      break;

    case "SpreadElement":
      node.type = "RestElement";
      node.argument = this.toAssignable(node.argument);
      break;

    case "AssignmentExpression":
      node.type = "AssignmentPattern";
      break;
    }
  }
  return this.checkLVal(node);
};

lp.toAssignableList = function(exprList) {
  for (var i = 0; i < exprList.length; i++)
    this.toAssignable(exprList[i]);
  return exprList;
};

lp.parseFunctionParams = function(params) {
  this.pushCx();
  params = this.parseExprList(tt.parenR);
  return this.toAssignableList(params);
};

lp.parseMethod = function(isGenerator) {
  var node = this.startNode();
  this.initFunction(node);
  node.params = this.parseFunctionParams();
  node.generator = isGenerator || false;
  node.expression = this.options.ecmaVersion >= 6 && this.tok.type !== tt.braceL;
  node.body = node.expression ? this.parseMaybeAssign() : this.parseBlock();
  return this.finishNode(node, "FunctionExpression");
};

lp.parseArrowExpression = function(node, params) {
  this.initFunction(node);
  node.params = this.toAssignableList(params);
  node.expression = this.tok.type !== tt.braceL;
  node.body = node.expression ? this.parseMaybeAssign() : this.parseBlock();
  return this.finishNode(node, "ArrowFunctionExpression");
};

lp.parseExport = function() {
  var node = this.startNode();
  this.next();
  if (this.eat(tt.star)) {
    node.source = this.eatContextual("from") ? this.parseExprAtom() : null;
    return this.finishNode(node, "ExportAllDeclaration");
  }
  if (this.eat(tt._default)) {
    var expr = this.parseMaybeAssign();
    if (expr.id) {
      switch (expr.type) {
      case "FunctionExpression": expr.type = "FunctionDeclaration"; break;
      case "ClassExpression": expr.type = "ClassDeclaration"; break;
      }
    }
    node.declaration = expr;
    this.semicolon();
    return this.finishNode(node, "ExportDefaultDeclaration");
  }
  if (this.tok.type.keyword) {
    node.declaration = this.parseStatement();
    node.specifiers = [];
    node.source = null;
  } else {
    node.declaration = null;
    node.specifiers = this.parseExportSpecifierList();
    node.source = this.eatContextual("from") ? this.parseExprAtom() : null;
    this.semicolon();
  }
  return this.finishNode(node, "ExportNamedDeclaration");
};

lp.parseImport = function() {
  var node = this.startNode();
  this.next();
  if (this.tok.type === tt.string) {
    node.specifiers = [];
    node.source = this.parseExprAtom();
    node.kind = '';
  } else {
    if (this.tok.type === tt.name && this.tok.value !== "from") {
      var elt = this.startNode();
      elt.local = this.parseIdent();
      this.finishNode(elt, "ImportDefaultSpecifier");
      this.eat(tt.comma);
    }
    node.specifiers = this.parseImportSpecifierList();
    node.source = this.eatContextual("from") ? this.parseExprAtom() : null;
    if (elt) node.specifiers.unshift(elt);
  }
  this.semicolon();
  return this.finishNode(node, "ImportDeclaration");
};

lp.parseImportSpecifierList = function() {
  var elts = [];
  if (this.tok.type === tt.star) {
    var elt = this.startNode();
    this.next();
    if (this.eatContextual("as")) elt.local = this.parseIdent();
    elts.push(this.finishNode(elt, "ImportNamespaceSpecifier"));
  } else {
    var indent = this.curIndent, line = this.curLineStart, continuedLine = this.nextLineStart;
    this.pushCx();
    this.eat(tt.braceL);
    if (this.curLineStart > continuedLine) continuedLine = this.curLineStart;
    while (!this.closes(tt.braceR, indent + (this.curLineStart <= continuedLine ? 1 : 0), line)) {
      var elt = this.startNode();
      if (this.eat(tt.star)) {
        if (this.eatContextual("as")) elt.local = this.parseIdent();
        this.finishNode(elt, "ImportNamespaceSpecifier");
      } else {
        if (this.isContextual("from")) break;
        elt.imported = this.parseIdent();
        elt.local = this.eatContextual("as") ? this.parseIdent() : elt.imported;
        this.finishNode(elt, "ImportSpecifier");
      }
      elts.push(elt);
      this.eat(tt.comma);
    }
    this.eat(tt.braceR);
    this.popCx();
  }
  return elts;
};

lp.parseExportSpecifierList = function() {
  var elts = [];
  var indent = this.curIndent, line = this.curLineStart, continuedLine = this.nextLineStart;
  this.pushCx();
  this.eat(tt.braceL);
  if (this.curLineStart > continuedLine) continuedLine = this.curLineStart;
  while (!this.closes(tt.braceR, indent + (this.curLineStart <= continuedLine ? 1 : 0), line)) {
    if (this.isContextual("from")) break;
    var elt = this.startNode();
    elt.local = this.parseIdent();
    elt.exported = this.eatContextual("as") ? this.parseIdent() : elt.local;
    this.finishNode(elt, "ExportSpecifier");
    elts.push(elt);
    this.eat(tt.comma);
  }
  this.eat(tt.braceR);
  this.popCx();
  return elts;
};

lp.parseExprList = function(close, allowEmpty) {
  var indent = this.curIndent, line = this.curLineStart, elts = [];
  this.next(); // Opening bracket
  while (!this.closes(close, indent + 1, line)) {
    if (this.eat(tt.comma)) {
      elts.push(allowEmpty ? null : this.dummyIdent());
      continue;
    }
    var elt = this.parseMaybeAssign();
    if (isDummy(elt)) {
      if (this.closes(close, indent, line)) break;
      this.next();
    } else {
      elts.push(elt);
    }
    this.eat(tt.comma);
  }
  this.popCx();
  if (!this.eat(close)) {
    // If there is no closing brace, make the node span to the start
    // of the next token (this is useful for Tern)
    this.last.end = this.tok.start;
    if (this.options.locations) this.last.loc.end = this.tok.loc.start;
  }
  return elts;
};