/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "txPatternParser.h"
#include "txExprLexer.h"
#include "nsGkAtoms.h"
#include "nsError.h"
#include "txStringUtils.h"
#include "txXSLTPatterns.h"
#include "txStylesheetCompiler.h"
#include "txPatternOptimizer.h"

#include "mozilla/UniquePtrExtensions.h"

using mozilla::UniquePtr;

nsresult txPatternParser::createPattern(const nsString& aPattern,
                                        txIParseContext* aContext,
                                        txPattern** aResult) {
  txExprLexer lexer;
  nsresult rv = lexer.parse(aPattern);
  if (NS_FAILED(rv)) {
    // XXX error report parsing error
    return rv;
  }
  UniquePtr<txPattern> pattern;
  rv = createUnionPattern(lexer, aContext, *getter_Transfers(pattern));
  if (NS_FAILED(rv)) {
    // XXX error report parsing error
    return rv;
  }

  txPatternOptimizer optimizer;
  txPattern* newPattern = nullptr;
  optimizer.optimize(pattern.get(), &newPattern);

  *aResult = newPattern ? newPattern : pattern.release();

  return NS_OK;
}

nsresult txPatternParser::createUnionPattern(txExprLexer& aLexer,
                                             txIParseContext* aContext,
                                             txPattern*& aPattern) {
  nsresult rv = NS_OK;
  txPattern* locPath = 0;

  rv = createLocPathPattern(aLexer, aContext, locPath);
  if (NS_FAILED(rv)) return rv;

  Token::Type type = aLexer.peek()->mType;
  if (type == Token::END) {
    aPattern = locPath;
    return NS_OK;
  }

  if (type != Token::UNION_OP) {
    delete locPath;
    return NS_ERROR_XPATH_PARSE_FAILURE;
  }

  txUnionPattern* unionPattern = new txUnionPattern();
  unionPattern->addPattern(locPath);

  aLexer.nextToken();
  do {
    rv = createLocPathPattern(aLexer, aContext, locPath);
    if (NS_FAILED(rv)) {
      delete unionPattern;
      return rv;
    }
    unionPattern->addPattern(locPath);
    type = aLexer.nextToken()->mType;
  } while (type == Token::UNION_OP);

  if (type != Token::END) {
    delete unionPattern;
    return NS_ERROR_XPATH_PARSE_FAILURE;
  }

  aPattern = unionPattern;
  return NS_OK;
}

nsresult txPatternParser::createLocPathPattern(txExprLexer& aLexer,
                                               txIParseContext* aContext,
                                               txPattern*& aPattern) {
  nsresult rv = NS_OK;

  bool isChild = true;
  bool isAbsolute = false;
  txPattern* stepPattern = 0;
  txLocPathPattern* pathPattern = 0;

  Token::Type type = aLexer.peek()->mType;
  switch (type) {
    case Token::ANCESTOR_OP:
      isChild = false;
      isAbsolute = true;
      aLexer.nextToken();
      break;
    case Token::PARENT_OP:
      aLexer.nextToken();
      isAbsolute = true;
      if (aLexer.peek()->mType == Token::END ||
          aLexer.peek()->mType == Token::UNION_OP) {
        aPattern = new txRootPattern();
        return NS_OK;
      }
      break;
    case Token::FUNCTION_NAME_AND_PAREN:
      // id(Literal) or key(Literal, Literal)
      {
        RefPtr<nsAtom> nameAtom = NS_Atomize(aLexer.nextToken()->Value());
        if (nameAtom == nsGkAtoms::id) {
          rv = createIdPattern(aLexer, stepPattern);
        } else if (nameAtom == nsGkAtoms::key) {
          rv = createKeyPattern(aLexer, aContext, stepPattern);
        }
        if (NS_FAILED(rv)) return rv;
      }
      break;
    default:
      break;
  }
  if (!stepPattern) {
    rv = createStepPattern(aLexer, aContext, stepPattern);
    if (NS_FAILED(rv)) return rv;
  }

  type = aLexer.peek()->mType;
  if (!isAbsolute && type != Token::PARENT_OP && type != Token::ANCESTOR_OP) {
    aPattern = stepPattern;
    return NS_OK;
  }

  pathPattern = new txLocPathPattern();
  if (isAbsolute) {
    txRootPattern* root = new txRootPattern();
#ifdef TX_TO_STRING
    root->setSerialize(false);
#endif

    pathPattern->addStep(root, isChild);
  }

  pathPattern->addStep(stepPattern, isChild);
  stepPattern = 0;  // stepPattern is part of pathPattern now

  while (type == Token::PARENT_OP || type == Token::ANCESTOR_OP) {
    isChild = type == Token::PARENT_OP;
    aLexer.nextToken();
    rv = createStepPattern(aLexer, aContext, stepPattern);
    if (NS_FAILED(rv)) {
      delete pathPattern;
      return rv;
    }
    pathPattern->addStep(stepPattern, isChild);
    stepPattern = 0;  // stepPattern is part of pathPattern now
    type = aLexer.peek()->mType;
  }
  aPattern = pathPattern;
  return rv;
}

nsresult txPatternParser::createIdPattern(txExprLexer& aLexer,
                                          txPattern*& aPattern) {
  // check for '(' Literal ')'
  if (aLexer.peek()->mType != Token::LITERAL)
    return NS_ERROR_XPATH_PARSE_FAILURE;
  const nsDependentSubstring& value = aLexer.nextToken()->Value();
  if (aLexer.nextToken()->mType != Token::R_PAREN)
    return NS_ERROR_XPATH_PARSE_FAILURE;
  aPattern = new txIdPattern(value);
  return NS_OK;
}

nsresult txPatternParser::createKeyPattern(txExprLexer& aLexer,
                                           txIParseContext* aContext,
                                           txPattern*& aPattern) {
  // check for '(' Literal, Literal ')'
  if (aLexer.peek()->mType != Token::LITERAL)
    return NS_ERROR_XPATH_PARSE_FAILURE;
  const nsDependentSubstring& key = aLexer.nextToken()->Value();
  if (aLexer.nextToken()->mType != Token::COMMA &&
      aLexer.peek()->mType != Token::LITERAL)
    return NS_ERROR_XPATH_PARSE_FAILURE;
  const nsDependentSubstring& value = aLexer.nextToken()->Value();
  if (aLexer.nextToken()->mType != Token::R_PAREN)
    return NS_ERROR_XPATH_PARSE_FAILURE;

  if (!aContext->allowed(txIParseContext::KEY_FUNCTION))
    return NS_ERROR_XSLT_CALL_TO_KEY_NOT_ALLOWED;

  const char16_t* colon;
  if (!XMLUtils::isValidQName(key, &colon)) {
    return NS_ERROR_XPATH_PARSE_FAILURE;
  }
  RefPtr<nsAtom> prefix, localName;
  int32_t namespaceID;
  nsresult rv = resolveQName(key, getter_AddRefs(prefix), aContext,
                             getter_AddRefs(localName), namespaceID);
  if (NS_FAILED(rv)) return rv;

  aPattern = new txKeyPattern(prefix, localName, namespaceID, value);
  return NS_OK;
}

nsresult txPatternParser::createStepPattern(txExprLexer& aLexer,
                                            txIParseContext* aContext,
                                            txPattern*& aPattern) {
  nsresult rv = NS_OK;
  bool isAttr = false;
  Token* tok = aLexer.peek();
  if (tok->mType == Token::AXIS_IDENTIFIER) {
    if (TX_StringEqualsAtom(tok->Value(), nsGkAtoms::attribute)) {
      isAttr = true;
    } else if (!TX_StringEqualsAtom(tok->Value(), nsGkAtoms::child)) {
      // all done already for CHILD_AXIS, for all others
      // XXX report unexpected axis error
      return NS_ERROR_XPATH_PARSE_FAILURE;
    }
    aLexer.nextToken();
  } else if (tok->mType == Token::AT_SIGN) {
    aLexer.nextToken();
    isAttr = true;
  }

  txNodeTest* nodeTest;
  if (aLexer.peek()->mType == Token::CNAME) {
    tok = aLexer.nextToken();

    // resolve QName
    RefPtr<nsAtom> prefix, lName;
    int32_t nspace;
    rv = resolveQName(tok->Value(), getter_AddRefs(prefix), aContext,
                      getter_AddRefs(lName), nspace, true);
    if (NS_FAILED(rv)) {
      // XXX error report namespace resolve failed
      return rv;
    }

    uint16_t nodeType = isAttr ? (uint16_t)txXPathNodeType::ATTRIBUTE_NODE
                               : (uint16_t)txXPathNodeType::ELEMENT_NODE;
    nodeTest = new txNameTest(prefix, lName, nspace, nodeType);
  } else {
    rv = createNodeTypeTest(aLexer, &nodeTest);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  UniquePtr<txStepPattern> step(new txStepPattern(nodeTest, isAttr));
  rv = parsePredicates(step.get(), aLexer, aContext);
  NS_ENSURE_SUCCESS(rv, rv);

  aPattern = step.release();

  return NS_OK;
}