/*
 * Copyright (c) 2023 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "source_map.h"

#include <cerrno>
#include <climits>
#include <cstdlib>
#include <fstream>
#include <vector>
#include <unistd.h>

#include "ecmascript/base/string_helper.h"
#include "ecmascript/extractortool/src/extractor.h"

namespace panda {
namespace ecmascript {
namespace {
static constexpr char DELIMITER_COMMA = ',';
static constexpr char DELIMITER_SEMICOLON = ';';
static constexpr char DOUBLE_SLASH = '\\';

static constexpr int32_t INDEX_ONE = 1;
static constexpr int32_t INDEX_TWO = 2;
static constexpr int32_t INDEX_THREE = 3;
static constexpr int32_t INDEX_FOUR = 4;
static constexpr int32_t ANS_MAP_SIZE = 5;
static constexpr int32_t DIGIT_NUM = 64;

const std::string MEGER_SOURCE_MAP_PATH = "ets/sourceMaps.map";
static const CString FLAG_SOURCES = "    \"sources\":";
static const CString FLAG_MAPPINGS = "    \"mappings\": \"";
static const CString FLAG_END = "  }";

static constexpr size_t FLAG_MAPPINGS_LEN = 17;
static constexpr size_t REAL_SOURCE_SIZE = 7;
static constexpr size_t REAL_URL_INDEX = 3;
static constexpr size_t REAL_SOURCE_INDEX = 7;
} // namespace

#if defined(PANDA_TARGET_OHOS)
bool SourceMap::ReadSourceMapData(const std::string& hapPath, std::string& content)
{
    if (hapPath.empty()) {
        return false;
    }
    bool newCreate = false;
    std::shared_ptr<Extractor> extractor = ExtractorUtil::GetExtractor(
        ExtractorUtil::GetLoadFilePath(hapPath), newCreate);
    if (extractor == nullptr) {
        return false;
    }
    std::unique_ptr<uint8_t[]> dataPtr = nullptr;
    size_t len = 0;
    if (!extractor->ExtractToBufByName(MEGER_SOURCE_MAP_PATH, dataPtr, len)) {
        return false;
    }
    content.assign(dataPtr.get(), dataPtr.get() + len);
    return true;
}
#endif

uint32_t SourceMap::Base64CharToInt(char charCode)
{
    if ('A' <= charCode && charCode <= 'Z') {
        // 0 - 25: ABCDEFGHIJKLMNOPQRSTUVWXYZ
        return charCode - 'A';
    } else if ('a' <= charCode && charCode <= 'z') {
        // 26 - 51: abcdefghijklmnopqrstuvwxyz
        return charCode - 'a' + 26;
    } else if ('0' <= charCode && charCode <= '9') {
        // 52 - 61: 0123456789
        return charCode - '0' + 52;
    } else if (charCode == '+') {
        // 62: +
        return 62;
    } else if (charCode == '/') {
        // 63: /
        return 63;
    }
    return DIGIT_NUM;
};

#if defined(PANDA_TARGET_OHOS)
void SourceMap::Init(const std::string& hapPath)
{
    auto start = Clock::now();
    std::string sourceMapData;
    if (ReadSourceMapData(hapPath, sourceMapData)) {
        SplitSourceMap(sourceMapData);
    }
    auto end = Clock::now();
    auto duration = std::chrono::duration_cast<std::chrono::milliseconds>(end - start);
    LOG_ECMA(DEBUG) << "Init sourcemap time: " << duration.count() << "ms";
}
#endif

void SourceMap::Init(uint8_t *data, size_t dataSize)
{
    std::string content;
    content.assign(data, data + dataSize);
    SplitSourceMap(content);
}

void SourceMap::SplitSourceMap(const std::string& sourceMapData)
{
    std::stringstream ss(sourceMapData);
    std::string tmp;
    std::string url;

    std::getline(ss, tmp);
    bool isUrl = true;
    while (std::getline(ss, tmp)) {
        if (isUrl && tmp.size() > REAL_SOURCE_SIZE) {
            url = tmp.substr(REAL_URL_INDEX, tmp.size() - REAL_SOURCE_SIZE);
            isUrl = false;
            continue;
        }

        if (base::StringHelper::StringStartWith(tmp.c_str(), FLAG_SOURCES)) {
            std::getline(ss, tmp);
            sources_.emplace(url, tmp);
            continue;
        }

        if (base::StringHelper::StringStartWith(tmp.c_str(), FLAG_MAPPINGS)) {
            mappings_.emplace(url, tmp);
            continue;
        }

        if (base::StringHelper::StringStartWith(tmp.c_str(), FLAG_END)) {
            isUrl = true;
        }
    }
}

void SourceMap::ExtractSourceMapData(const std::string& allmappings, std::shared_ptr<SourceMapData>& curMapData)
{
    curMapData->mappings_ = HandleMappings(allmappings);

    // the first bit: the column after transferring.
    // the second bit: the source file.
    // the third bit: the row before transferring.
    // the fourth bit: the column before transferring.
    // the fifth bit: the variable name.
    for (const auto& mapping : curMapData->mappings_) {
        if (mapping == ";") {
            // plus a line for each semicolon
            curMapData->nowPos_.afterRow++,
            curMapData->nowPos_.afterColumn = 0;
            continue;
        }
        std::vector<int32_t> ans;

        if (!VlqRevCode(mapping, ans)) {
            return;
        }
        if (ans.empty()) {
            break;
        }
        if (ans.size() == 1) {
            curMapData->nowPos_.afterColumn += ans[0];
            continue;
        }
        // after decode, assgin each value to the position
        curMapData->nowPos_.afterColumn += ans[0];
        curMapData->nowPos_.sourcesVal += ans[INDEX_ONE];
        curMapData->nowPos_.beforeRow += ans[INDEX_TWO];
        curMapData->nowPos_.beforeColumn += ans[INDEX_THREE];
        if (ans.size() == ANS_MAP_SIZE) {
            curMapData->nowPos_.namesVal += ans[INDEX_FOUR];
        }
        curMapData->afterPos_.push_back({
            curMapData->nowPos_.beforeRow,
            curMapData->nowPos_.beforeColumn,
            curMapData->nowPos_.afterRow,
            curMapData->nowPos_.afterColumn,
            curMapData->nowPos_.sourcesVal,
            curMapData->nowPos_.namesVal
        });
    }
    curMapData->mappings_.clear();
    curMapData->mappings_.shrink_to_fit();
}

MappingInfo SourceMap::Find(int32_t row, int32_t col, const SourceMapData& targetMap, bool& isReplaces)
{
    if (row < 1 || col < 1) {
        LOG_ECMA(ERROR) << "SourceMap find failed, line: " << row << ", column: " << col;
        return MappingInfo { 0, 0 };
    } else if (targetMap.afterPos_.empty()) {
        LOG_ECMA(ERROR) << "Target map can't find after pos.";
        return MappingInfo { 0, 0 };
    }
    row--;
    col--;
    // binary search
    int32_t left = 0;
    int32_t right = static_cast<int32_t>(targetMap.afterPos_.size()) - 1;
    int32_t res = 0;
    if (row > targetMap.afterPos_[targetMap.afterPos_.size() - 1].afterRow) {
        isReplaces = false;
        return MappingInfo { row + 1, col + 1};
    }
    while (right - left >= 0) {
        int32_t mid = (right + left) / 2;
        if ((targetMap.afterPos_[mid].afterRow == row && targetMap.afterPos_[mid].afterColumn > col) ||
             targetMap.afterPos_[mid].afterRow > row) {
            right = mid - 1;
        } else {
            res = mid;
            left = mid + 1;
        }
    }
    return MappingInfo { targetMap.afterPos_[res].beforeRow + 1, targetMap.afterPos_[res].beforeColumn + 1 };
}

void SourceMap::ExtractKeyInfo(const std::string& sourceMap, std::vector<std::string>& sourceKeyInfo)
{
    uint32_t cnt = 0;
    std::string tempStr;
    for (uint32_t i = 0; i < sourceMap.size(); i++) {
        // reslove json file
        if (sourceMap[i] == DOUBLE_SLASH) {
            i++;
            tempStr += sourceMap[i];
            continue;
        }
        // cnt is used to represent a pair of double quotation marks: ""
        if (sourceMap[i] == '"') {
            cnt++;
        }
        if (cnt == INDEX_TWO) {
            sourceKeyInfo.push_back(tempStr);
            tempStr = "";
            cnt = 0;
        } else if (cnt == 1) {
            if (sourceMap[i] != '"') {
                tempStr += sourceMap[i];
            }
        }
    }
}

void SourceMap::GetPosInfo(const std::string& temp, int32_t start, std::string& line, std::string& column)
{
    // 0 for colum, 1 for row
    int32_t flag = 0;
    // find line, column
    for (int32_t i = start - 1; i > 0; i--) {
        if (temp[i] == ':') {
            flag += 1;
            continue;
        }
        if (flag == 0) {
            column = temp[i] + column;
        } else if (flag == 1) {
            line = temp[i] + line;
        } else {
            break;
        }
    }
}

std::vector<std::string> SourceMap::HandleMappings(const std::string& mapping)
{
    std::vector<std::string> keyInfo;
    std::string tempStr;
    for (uint32_t i = 0; i < mapping.size(); i++) {
        if (mapping[i] == DELIMITER_COMMA) {
            keyInfo.push_back(tempStr);
            tempStr = "";
        } else if (mapping[i] == DELIMITER_SEMICOLON) {
            if (tempStr != "") {
                keyInfo.push_back(tempStr);
            }
            tempStr = "";
            keyInfo.push_back(";");
        } else {
            tempStr += mapping[i];
        }
    }
    if (tempStr != "") {
        keyInfo.push_back(tempStr);
    }
    return keyInfo;
};

bool SourceMap::VlqRevCode(const std::string& vStr, std::vector<int32_t>& ans)
{
    const int32_t VLQ_BASE_SHIFT = 5;
    // binary: 100000
    uint32_t VLQ_BASE = 1 << VLQ_BASE_SHIFT;
    // binary: 011111
    uint32_t VLQ_BASE_MASK = VLQ_BASE - 1;
    // binary: 100000
    uint32_t VLQ_CONTINUATION_BIT = VLQ_BASE;
    uint32_t result = 0;
    uint32_t shift = 0;
    bool continuation = 0;
    for (uint32_t i = 0; i < vStr.size(); i++) {
        uint32_t digit = Base64CharToInt(vStr[i]);
        if (digit == DIGIT_NUM) {
            return false;
        }
        continuation = digit & VLQ_CONTINUATION_BIT;
        digit &= VLQ_BASE_MASK;
        result += digit << shift;
        if (continuation) {
            shift += VLQ_BASE_SHIFT;
        } else {
            bool isNegate = result & 1;
            result >>= 1;
            ans.push_back(isNegate ? -result : result);
            result = 0;
            shift = 0;
        }
    }
    if (continuation) {
        return false;
    }
    return true;
};

bool SourceMap::TranslateUrlPositionBySourceMap(std::string& url, int& line, int& column)
{
    std::string tmp = sources_[url];
    if (tmp.empty() || tmp.size() < REAL_SOURCE_SIZE + 1) {
        LOG_ECMA(ERROR) << "Translate failed, url: " << url;
        return false;
    }
    tmp = tmp.substr(REAL_SOURCE_INDEX, tmp.size() - REAL_SOURCE_SIZE - 1);
    if (url.rfind(".js") != std::string::npos) {
        url = tmp;
        return true;
    }
    bool isReplaces = true;
    bool ret = false;
    auto iterData = sourceMaps_.find(url);
    if (iterData != sourceMaps_.end()) {
        if (iterData->second == nullptr) {
            LOG_ECMA(ERROR) << "Extract mappings failed, url: " << url;
            return false;
        }
        ret = GetLineAndColumnNumbers(line, column, *(iterData->second), isReplaces);
        if (isReplaces) {
            url = tmp;
        }
        return ret;
    }
    auto iter = mappings_.find(url);
    if (iter != mappings_.end()) {
        std::string mappings = mappings_[url];
        if (mappings.size() < FLAG_MAPPINGS_LEN + 1) {
            LOG_ECMA(ERROR) << "Translate failed, url: " << url << ", mappings: " << mappings;
            return false;
        }
        std::shared_ptr<SourceMapData> modularMap = std::make_shared<SourceMapData>();
        if (modularMap == nullptr) {
            LOG_ECMA(ERROR) << "New SourceMapData failed";
            return false;
        }
        ExtractSourceMapData(mappings.substr(FLAG_MAPPINGS_LEN, mappings.size() - FLAG_MAPPINGS_LEN - 1), modularMap);
        sourceMaps_.emplace(url, modularMap);
        ret = GetLineAndColumnNumbers(line, column, *(modularMap), isReplaces);
        if (isReplaces) {
            url = tmp;
        }
        return ret;
    }
    return false;
}

bool SourceMap::GetLineAndColumnNumbers(int& line, int& column, SourceMapData& targetMap, bool& isReplaces)
{
    int32_t offSet = 0;
    MappingInfo mapInfo;
#if defined(WINDOWS_PLATFORM) || defined(MAC_PLATFORM)
    mapInfo = Find(line - offSet + OFFSET_PREVIEW, column, targetMap, isReplaces);
#else
    mapInfo = Find(line - offSet, column, targetMap, isReplaces);
#endif
    if (mapInfo.row == 0 || mapInfo.col == 0) {
        return false;
    } else {
        line = mapInfo.row;
        column = mapInfo.col;
        return true;
    }
}
}   // namespace panda
}   // namespace ecmascript