#include <string>
#include <vector>
#include <stdexcept>

#include "log.h"
#include "filters.h"

Filter::~Filter() {
}


IntegerFilter::IntegerFilter(FilterKey key_, size_t other_, bool inverted_, bool disabled)
        : key(key_), other(other_), inverted(inverted_), _disabled(disabled) {
    if (key_ != FilterKey::PID && key_ != FilterKey::TID) {
        throw std::runtime_error("IntegerFilter is passed a non-integer key");
    }
}

void IntegerFilter::updated() {
}

bool IntegerFilter::disabled() const {
    return this->_disabled;
}

void IntegerFilter::disabled(bool disabled) {
    this->_disabled = disabled;
}

std::unique_ptr<Filter> IntegerFilter::clone() const {
    return std::make_unique<IntegerFilter>(this->key, this->other, this->inverted, this->_disabled);
}

const std::string* IntegerFilter::error() const {
    return nullptr;
}

bool IntegerFilter::match(const LogcatEntry& entry) const {
    bool matched;
    switch (this->key) {
        case FilterKey::PID: matched = entry.pid == this->other; break;
        case FilterKey::TID: matched = entry.tid == this->other; break;
        default: throw std::runtime_error("IntegerFilter::match received unhandled key");
    };
    return !this->inverted ? matched : !matched;
}


StringFilter::StringFilter(FilterKey key_, std::string other_, bool inverted_, bool exact_match_, bool disabled)
        : key(key_), other(std::move(other_)), inverted(inverted_), exact_match(exact_match_), _disabled(disabled) {
    if (key_ != FilterKey::User && key_ != FilterKey::Tag && key_ != FilterKey::Message) {
        throw std::runtime_error("StringFilter is passed a non-string key");
    }
    this->updated();
}

void StringFilter::updated() {
    this->_regex.reset();
    this->_error.clear();

    if (this->other.empty()) {
        this->_error = "String must not be empty";
        return;
    }
    if (!this->other.starts_with("regex:")) {
        return;
    }
    if (this->other.size() == 6) {
        this->_error = "Regex must not be empty";
        return;
    }

    try {
        this->_regex.emplace(&this->other.c_str()[6]);
    } catch (const std::exception& e) {
        this->_error = e.what();
    }
}

bool StringFilter::disabled() const {
    return this->_disabled;
}

void StringFilter::disabled(bool disabled) {
    this->_disabled = disabled;
}

std::unique_ptr<Filter> StringFilter::clone() const {
    return std::make_unique<StringFilter>(this->key, this->other, this->inverted, this->exact_match, this->_disabled);
}

const std::string* StringFilter::error() const {
    return !this->_error.empty() ? &this->_error : nullptr;
}

bool StringFilter::_match_no_regex(const LogcatEntry& entry) const {
    if (this->exact_match) {
        switch (this->key) {
            case FilterKey::User: return entry.user && *entry.user == this->other;
            case FilterKey::Tag: return entry.tag == this->other;
            case FilterKey::Message: return entry.message == this->other;
            default: throw std::runtime_error("StringFilter::match received unhandled key");
        }
    } else {
        switch (this->key) {
            case FilterKey::User: return entry.user && entry.user->find(this->other) != std::string::npos;
            case FilterKey::Tag: return entry.tag.find(this->other) != std::string::npos;
            case FilterKey::Message: return entry.message.find(this->other) != std::string::npos;
            default: throw std::runtime_error("StringFilter::match received unhandled key");
        }
    }
}

bool StringFilter::_match_regex(const LogcatEntry& entry) const {
    if (!this->_regex) {
        log("StringFilter::match called with a regex despite there being no regex");
        return true;
    }

    bool matched;
    const std::string* str;
    regmatch_t pmatch[1];
    int eflags = REG_STARTEND;

    switch (this->key) {
        case FilterKey::User: str = entry.user ? &*entry.user : nullptr; break;
        case FilterKey::Tag: str = &entry.tag; break;
        case FilterKey::Message: str = &entry.message; break;
        default: throw std::runtime_error("StringFilter::match received unhandled key");
    }
    pmatch[0].rm_so = 0;
    pmatch[0].rm_eo = str ? static_cast<regoff_t>(str->size()) : 0;
    if (!this->exact_match) {
        eflags |= REG_NOSUB;
    }

    matched = this->_regex->match(str ? str->data() : "", 1, pmatch, eflags);
    if (this->exact_match) {
        matched = matched && pmatch[0].rm_so == 0 && (str
            ? static_cast<size_t>(pmatch[0].rm_eo) == str->size()
            : pmatch[0].rm_eo == 0);
    }
    return matched;
}

bool StringFilter::match(const LogcatEntry& entry) const {
    if (this->error()) {
        log(std::string("StringFilter::match called despite there being an error: ") + *this->error());
        return true;
    }

    bool matched = !this->other.starts_with("regex:")
        ? this->_match_no_regex(entry)
        : this->_match_regex(entry);
    return !this->inverted ? matched : !matched;
}


BufferFilter::BufferFilter(unsigned int wanted_, bool disabled) : wanted(wanted_), _disabled(disabled) {
}

void BufferFilter::updated() {
}

bool BufferFilter::disabled() const {
    return this->_disabled;
}

void BufferFilter::disabled(bool disabled) {
    this->_disabled = disabled;
}

std::unique_ptr<Filter> BufferFilter::clone() const {
    return std::make_unique<BufferFilter>(this->wanted, this->_disabled);
}

const std::string* BufferFilter::error() const {
    return nullptr;
}

bool BufferFilter::match(const LogcatEntry& entry) const {
    return this->wanted & static_cast<unsigned int>(entry.buffer) || this->wanted == 0;
}


PriorityFilter::PriorityFilter(unsigned int wanted_, bool disabled) : wanted(wanted_), _disabled(disabled) {
}

void PriorityFilter::updated() {
}

bool PriorityFilter::disabled() const {
    return this->_disabled;
}

void PriorityFilter::disabled(bool disabled) {
    this->_disabled = disabled;
}

std::unique_ptr<Filter> PriorityFilter::clone() const {
    return std::make_unique<PriorityFilter>(this->wanted, this->_disabled);
}

const std::string* PriorityFilter::error() const {
    return nullptr;
}

bool PriorityFilter::match(const LogcatEntry& entry) const {
    return this->wanted & static_cast<unsigned int>(entry.priority) || this->wanted == 0;
}


GroupFilter::GroupFilter(std::vector<std::unique_ptr<Filter>> filters_, GroupFilter::Type type_, bool disabled)
        : filters(std::move(filters_)), type(type_), _disabled(disabled) {
}

void GroupFilter::updated() {
}

bool GroupFilter::disabled() const {
    return this->_disabled;
}

void GroupFilter::disabled(bool disabled) {
    this->_disabled = disabled;
}

std::unique_ptr<Filter> GroupFilter::clone() const {
    std::vector<std::unique_ptr<Filter>> new_filters;
    new_filters.reserve(this->filters.size());

    for (const std::unique_ptr<Filter>& filter : this->filters) {
        new_filters.push_back(filter->clone());
    }

    return std::make_unique<GroupFilter>(std::move(new_filters), this->type, this->_disabled);
}

const std::string* GroupFilter::error() const {
    return nullptr;
}

bool GroupFilter::match(const LogcatEntry& entry) const {
    bool had_matched = false;

    for (const std::unique_ptr<Filter>& filter : this->filters) {
        if (filter->disabled() || filter->error()) {
            continue;
        }

        bool matched = filter->match(entry);
        if (this->type == GroupFilter::Type::Any && matched) {
            return true;
        } else if (this->type == GroupFilter::Type::None && matched) {
            return false;
        } else if (this->type == GroupFilter::Type::All && !matched) {
            return false;
        } else if (this->type == GroupFilter::Type::One) {
            if (had_matched && matched) {
                return false;
            }
            if (matched) {
                had_matched = true;
            }
        }
    }

    if (this->type == GroupFilter::Type::Any) {
        return false;
    } else if (this->type == GroupFilter::Type::One && !had_matched) {
        return false;
    }
    return true;
}


void copy_filters(Filters& __restrict filters, const Filters& __restrict other) {
    filters.clear();
    filters.reserve(other.size());

    for (const auto &[title, filter] : other) {
        filters.push_back(std::make_pair(title, filter->clone()));
    }
}

static bool matches(const LogcatEntry& entry, const Filters& filters, bool return_true_if_empty) {
    for (const auto &[_, filter] : filters) {
        if (filter->disabled() || filter->error()) {
            continue;
        }
        if (filter->match(entry)) {
            return true;
        }
        return_true_if_empty = false;
    }

    return return_true_if_empty;
}

bool matches(const LogcatEntry& entry, const Filters& __restrict filters, const Filters& __restrict exclusions) {
    return !matches(entry, exclusions, false) && matches(entry, filters, true);
}


void from_json(const nlohmann::json& j, FilterKey& key) {
    const std::string& str = j.get_ref<const nlohmann::json::string_t&>();

    if (str == "BUFFER") key = FilterKey::Buffer;
    else if (str == "USER") key = FilterKey::User;
    else if (str == "PID") key = FilterKey::PID;
    else if (str == "TID") key = FilterKey::TID;
    else if (str == "PRIORITY") key = FilterKey::Priority;
    else if (str == "TAG") key = FilterKey::Tag;
    else if (str == "MESSAGE") key = FilterKey::Message;
    else throw std::invalid_argument(std::string("Unknown filter key: ") + str);
}

void to_json(nlohmann::json& j, const FilterKey& key) {
    switch (key) {
        case FilterKey::Buffer: j = "BUFFER"; break;
        case FilterKey::User: j = "USER"; break;
        case FilterKey::PID: j = "PID"; break;
        case FilterKey::TID: j = "TID"; break;
        case FilterKey::Priority: j = "PRIORITY"; break;
        case FilterKey::Tag: j = "TAG"; break;
        case FilterKey::Message: j = "MESSAGE"; break;
    }
}

void from_json(const nlohmann::json& j, GroupFilter::Type& type) {
    const std::string& str = j.get_ref<const nlohmann::json::string_t&>();

    if (str == "ALL") type = GroupFilter::Type::All;
    else if (str == "ANY") type = GroupFilter::Type::Any;
    else if (str == "ONE") type = GroupFilter::Type::One;
    else if (str == "NONE") type = GroupFilter::Type::None;
    else throw std::invalid_argument(std::string("Unknown group filter type: ") + str);
}

void to_json(nlohmann::json& j, const GroupFilter::Type& type) {
    switch (type) {
        case GroupFilter::Type::All: j = "ALL"; break;
        case GroupFilter::Type::Any: j = "ANY"; break;
        case GroupFilter::Type::One: j = "ONE"; break;
        case GroupFilter::Type::None: j = "NONE"; break;
    }
}

void from_json(const nlohmann::json& j, std::unique_ptr<Filter>& filter) {
    const std::string& filter_type = j.at("type").get_ref<const nlohmann::json::string_t&>();
    bool disabled = j.at("disabled").get<bool>();

    if (filter_type == "INTEGER") {
        filter = std::make_unique<IntegerFilter>(j.at("key").get<FilterKey>(), j.at("other").get<size_t>(), j.at("inverted").get<bool>(), disabled);
    } else if (filter_type == "STRING") {
        filter = std::make_unique<StringFilter>(
            j.at("key").get<FilterKey>(), j.at("other").get<std::string>(), j.at("inverted").get<bool>(), j.at("exact_match").get<bool>(), disabled);
    } else if (filter_type == "BUFFER") {
        unsigned int wanted = 0;
        nlohmann::json wanted_json = j.at("wanted");
        if (!wanted_json.is_array()) {
            throw std::invalid_argument("Wanted buffer items is not an array");
        }
        for (nlohmann::json::const_iterator it = wanted_json.cbegin(); it != wanted_json.cend(); it++) {
            wanted |= static_cast<unsigned int>(it->get<Buffer>());
        }

        filter = std::make_unique<BufferFilter>(wanted, disabled);
    } else if (filter_type == "PRIORITY") {
        unsigned int wanted = 0;
        nlohmann::json wanted_json = j.at("wanted");
        if (!wanted_json.is_array()) {
            throw std::invalid_argument("Wanted priority items is not an array");
        }
        for (nlohmann::json::const_iterator it = wanted_json.cbegin(); it != wanted_json.cend(); it++) {
            wanted |= static_cast<unsigned int>(it->get<Priority>());
        }

        filter = std::make_unique<PriorityFilter>(wanted, disabled);
    } else if (filter_type == "GROUP") {
        filter = std::make_unique<GroupFilter>(
            j.at("filters").get<std::vector<std::unique_ptr<Filter>>>(), j.at("group_type").get<GroupFilter::Type>(), disabled);
    } else {
        throw std::invalid_argument(std::string("Unknown filter type: ") + filter_type);
    }
}

void to_json(nlohmann::json& j, const std::unique_ptr<Filter>& filter) {
    j["disabled"] = filter->disabled();

    if (const IntegerFilter* ifilter = dynamic_cast<const IntegerFilter*>(filter.get())) {
        j["type"] = "INTEGER";
        j["key"] = ifilter->key;
        j["other"] = ifilter->other;
        j["inverted"] = ifilter->inverted;
    } else if (const StringFilter* sfilter = dynamic_cast<const StringFilter*>(filter.get())) {
        j["type"] = "STRING";
        j["key"] = sfilter->key;
        j["other"] = sfilter->other;
        j["inverted"] = sfilter->inverted;
        j["exact_match"] = sfilter->exact_match;
    } else if (const BufferFilter* bfilter = dynamic_cast<const BufferFilter*>(filter.get())) {
        j["type"] = "BUFFER";
        j["wanted"] = nlohmann::json::array();
        if (bfilter->wanted & static_cast<unsigned int>(Buffer::Unknown)) {
            j["wanted"].emplace_back(Buffer::Unknown);
        }
        if (bfilter->wanted & static_cast<unsigned int>(Buffer::Main)) {
            j["wanted"].emplace_back(Buffer::Main);
        }
        if (bfilter->wanted & static_cast<unsigned int>(Buffer::System)) {
            j["wanted"].emplace_back(Buffer::System);
        }
        if (bfilter->wanted & static_cast<unsigned int>(Buffer::Radio)) {
            j["wanted"].emplace_back(Buffer::Radio);
        }
        if (bfilter->wanted & static_cast<unsigned int>(Buffer::Events)) {
            j["wanted"].emplace_back(Buffer::Events);
        }
        if (bfilter->wanted & static_cast<unsigned int>(Buffer::Crash)) {
            j["wanted"].emplace_back(Buffer::Crash);
        }
    } else if (const PriorityFilter* pfilter = dynamic_cast<const PriorityFilter*>(filter.get())) {
        j["type"] = "PRIORITY";
        j["wanted"] = nlohmann::json::array();
        if (pfilter->wanted & static_cast<unsigned int>(Priority::Unknown)) {
            j["wanted"].emplace_back(Priority::Unknown);
        }
        if (pfilter->wanted & static_cast<unsigned int>(Priority::Verbose)) {
            j["wanted"].emplace_back(Priority::Verbose);
        }
        if (pfilter->wanted & static_cast<unsigned int>(Priority::Debug)) {
            j["wanted"].emplace_back(Priority::Debug);
        }
        if (pfilter->wanted & static_cast<unsigned int>(Priority::Info)) {
            j["wanted"].emplace_back(Priority::Info);
        }
        if (pfilter->wanted & static_cast<unsigned int>(Priority::Warn)) {
            j["wanted"].emplace_back(Priority::Warn);
        }
        if (pfilter->wanted & static_cast<unsigned int>(Priority::Error)) {
            j["wanted"].emplace_back(Priority::Error);
        }
        if (pfilter->wanted & static_cast<unsigned int>(Priority::Fatal)) {
            j["wanted"].emplace_back(Priority::Fatal);
        }
    } else if (const GroupFilter* gfilter = dynamic_cast<const GroupFilter*>(filter.get())) {
        j["type"] = "GROUP";
        j["group_type"] = gfilter->type;
        j["filters"] = nlohmann::json::array();
        for (const std::unique_ptr<Filter>& i : gfilter->filters) {
            j["filters"].emplace_back(i);
        }
    } else {
        throw std::invalid_argument("Cannot serialize unknown filter");
    }
}