/* Copyright (c) 2013 Dropbox, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "json11.hpp"
#include <cassert>
#include <cmath>
#include <cstdlib>
#include <cstdio>
#include <limits>

namespace json11 {

static const int max_depth = 200;

using std::string;
using std::vector;
using std::map;
using std::make_shared;
using std::initializer_list;
using std::move;

/* Helper for representing null - just a do-nothing struct, plus comparison
 * operators so the helpers in JsonValue work. We can't use nullptr_t because
 * it may not be orderable.
 */
struct NullStruct {
    bool operator==(NullStruct) const { return true; }
    bool operator<(NullStruct) const { return false; }
};

/* * * * * * * * * * * * * * * * * * * *
 * Serialization
 */

static void dump(NullStruct, string &out) {
    out += "null";
}

static void dump(double value, string &out) {
    if (std::isfinite(value)) {
        char buf[32];
        snprintf(buf, sizeof buf, "%.17g", value);
        out += buf;
    } else {
        out += "null";
    }
}

static void dump(int value, string &out) {
    char buf[32];
    snprintf(buf, sizeof buf, "%d", value);
    out += buf;
}

static void dump(bool value, string &out) {
    out += value ? "true" : "false";
}

static void dump(const string &value, string &out) {
    out += '"';
    for (size_t i = 0; i < value.length(); i++) {
        const char ch = value[i];
        if (ch == '\\') {
            out += "\\\\";
        } else if (ch == '"') {
            out += "\\\"";
        } else if (ch == '\b') {
            out += "\\b";
        } else if (ch == '\f') {
            out += "\\f";
        } else if (ch == '\n') {
            out += "\\n";
        } else if (ch == '\r') {
            out += "\\r";
        } else if (ch == '\t') {
            out += "\\t";
        } else if (static_cast<uint8_t>(ch) <= 0x1f) {
            char buf[8];
            snprintf(buf, sizeof buf, "\\u%04x", ch);
            out += buf;
        } else if (static_cast<uint8_t>(ch) == 0xe2 && static_cast<uint8_t>(value[i+1]) == 0x80
                   && static_cast<uint8_t>(value[i+2]) == 0xa8) {
            out += "\\u2028";
            i += 2;
        } else if (static_cast<uint8_t>(ch) == 0xe2 && static_cast<uint8_t>(value[i+1]) == 0x80
                   && static_cast<uint8_t>(value[i+2]) == 0xa9) {
            out += "\\u2029";
            i += 2;
        } else {
            out += ch;
        }
    }
    out += '"';
}

static void dump(const Json::array &values, string &out) {
    bool first = true;
    out += "[";
    for (const auto &value : values) {
        if (!first)
            out += ", ";
        value.dump(out);
        first = false;
    }
    out += "]";
}

static void dump(const Json::object &values, string &out) {
    bool first = true;
    out += "{";
    for (const auto &kv : values) {
        if (!first)
            out += ", ";
        dump(kv.first, out);
        out += ": ";
        kv.second.dump(out);
        first = false;
    }
    out += "}";
}

void Json::dump(string &out) const {
    m_ptr->dump(out);
}

/* * * * * * * * * * * * * * * * * * * *
 * Value wrappers
 */

template <Json::Type tag, typename T>
class Value : public JsonValue {
protected:

    // Constructors
    explicit Value(const T &value) : m_value(value) {}
    explicit Value(T &&value)      : m_value(move(value)) {}

    // Get type tag
    Json::Type type() const override {
        return tag;
    }

    // Comparisons
    bool equals(const JsonValue * other) const override {
        return m_value == static_cast<const Value<tag, T> *>(other)->m_value;
    }
    bool less(const JsonValue * other) const override {
        return m_value < static_cast<const Value<tag, T> *>(other)->m_value;
    }

    const T m_value;
    void dump(string &out) const override { json11::dump(m_value, out); }
};

class JsonDouble final : public Value<Json::NUMBER, double> {
    double number_value() const override { return m_value; }
    int int_value() const override { return static_cast<int>(m_value); }
    bool equals(const JsonValue * other) const override { return m_value == other->number_value(); }
    bool less(const JsonValue * other)   const override { return m_value <  other->number_value(); }
public:
    explicit JsonDouble(double value) : Value(value) {}
};

class JsonInt final : public Value<Json::NUMBER, int> {
    double number_value() const override { return m_value; }
    int int_value() const override { return m_value; }
    bool equals(const JsonValue * other) const override { return m_value == other->number_value(); }
    bool less(const JsonValue * other)   const override { return m_value <  other->number_value(); }
public:
    explicit JsonInt(int value) : Value(value) {}
};

class JsonBoolean final : public Value<Json::BOOL, bool> {
    bool bool_value() const override { return m_value; }
public:
    explicit JsonBoolean(bool value) : Value(value) {}
};

class JsonString final : public Value<Json::STRING, string> {
    const string &string_value() const override { return m_value; }
public:
    explicit JsonString(const string &value) : Value(value) {}
    explicit JsonString(string &&value)      : Value(move(value)) {}
};

class JsonArray final : public Value<Json::ARRAY, Json::array> {
    const Json::array &array_items() const override { return m_value; }
    const Json & operator[](size_t i) const override;
public:
    explicit JsonArray(const Json::array &value) : Value(value) {}
    explicit JsonArray(Json::array &&value)      : Value(move(value)) {}
};

class JsonObject final : public Value<Json::OBJECT, Json::object> {
    const Json::object &object_items() const override { return m_value; }
    const Json & operator[](const string &key) const override;
public:
    explicit JsonObject(const Json::object &value) : Value(value) {}
    explicit JsonObject(Json::object &&value)      : Value(move(value)) {}
};

class JsonNull final : public Value<Json::NUL, NullStruct> {
public:
    JsonNull() : Value({}) {}
};

/* * * * * * * * * * * * * * * * * * * *
 * Static globals - static-init-safe
 */
struct Statics {
    const std::shared_ptr<JsonValue> null = make_shared<JsonNull>();
    const std::shared_ptr<JsonValue> t = make_shared<JsonBoolean>(true);
    const std::shared_ptr<JsonValue> f = make_shared<JsonBoolean>(false);
    const string empty_string;
    const vector<Json> empty_vector;
    const map<string, Json> empty_map;
    Statics() {}
};

static const Statics & statics() {
    static const Statics s {};
    return s;
}

static const Json & static_null() {
    // This has to be separate, not in Statics, because Json() accesses statics().null.
    static const Json json_null;
    return json_null