// Copyright 2015-2016 Espressif Systems (Shanghai) PTE 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 "nvs_storage.hpp"

#ifndef ESP_PLATFORM
#include <map>
#include <sstream>
#endif

namespace nvs
{

Storage::~Storage()
{
    clearNamespaces();
}

void Storage::clearNamespaces()
{
    for (auto it = std::begin(mNamespaces); it != std::end(mNamespaces); ) {
        auto tmp = it;
        ++it;
        mNamespaces.erase(tmp);
        delete static_cast<NamespaceEntry*>(tmp);
    }
}

esp_err_t Storage::init(uint32_t baseSector, uint32_t sectorCount)
{
    auto err = mPageManager.load(baseSector, sectorCount);
    if (err != ESP_OK) {
        mState = StorageState::INVALID;
        return err;
    }

    // load namespaces list
    clearNamespaces();
    std::fill_n(mNamespaceUsage.data(), mNamespaceUsage.byteSize() / 4, 0);
    for (auto it = mPageManager.begin(); it != mPageManager.end(); ++it) {
        Page& p = *it;
        size_t itemIndex = 0;
        Item item;
        while (p.findItem(Page::NS_INDEX, ItemType::U8, nullptr, itemIndex, item) == ESP_OK) {
            NamespaceEntry* entry = new NamespaceEntry;
            item.getKey(entry->mName, sizeof(entry->mName) - 1);
            item.getValue(entry->mIndex);
            mNamespaces.push_back(entry);
            mNamespaceUsage.set(entry->mIndex, true);
            itemIndex += item.span;
        }
    }
    mNamespaceUsage.set(0, true);
    mNamespaceUsage.set(255, true);
    mState = StorageState::ACTIVE;
#ifndef ESP_PLATFORM
    debugCheck();
#endif
    return ESP_OK;
}

esp_err_t Storage::findItem(uint8_t nsIndex, ItemType datatype, const char* key, Page* &page, Item& item)
{
    size_t itemIndex = 0;
    for (auto it = std::begin(mPageManager); it != std::end(mPageManager); ++it) {
        auto err = it->findItem(nsIndex, datatype, key, itemIndex, item);
        if (err == ESP_OK) {
            page = it;
            return ESP_OK;
        }
    }
    return ESP_ERR_NVS_NOT_FOUND;
}

esp_err_t Storage::writeItem(uint8_t nsIndex, ItemType datatype, const char* key, const void* data, size_t dataSize)
{
    if (mState != StorageState::ACTIVE) {
        return ESP_ERR_NVS_NOT_INITIALIZED;
    }

    Page* findPage = nullptr;
    Item item;
    auto err = findItem(nsIndex, datatype, key, findPage, item);
    if (err != ESP_OK && err != ESP_ERR_NVS_NOT_FOUND) {
        return err;
    }

    Page& page = getCurrentPage();
    err = page.writeItem(nsIndex, datatype, key, data, dataSize);
    if (err == ESP_ERR_NVS_PAGE_FULL) {
        if (page.state() != Page::PageState::FULL) {
            err = page.markFull();
            if (err != ESP_OK) {
                return err;
            }
        }
        err = mPageManager.requestNewPage();
        if (err != ESP_OK) {
            return err;
        }

        err = getCurrentPage().writeItem(nsIndex, datatype, key, data, dataSize);
        if (err == ESP_ERR_NVS_PAGE_FULL) {
            return ESP_ERR_NVS_NOT_ENOUGH_SPACE;
        }
        if (err != ESP_OK) {
            return err;
        }
    } else if (err != ESP_OK) {
        return err;
    }

    if (findPage) {
        if (findPage->state() == Page::PageState::UNINITIALIZED ||
                findPage->state() == Page::PageState::INVALID) {
            ESP_ERROR_CHECK( findItem(nsIndex, datatype, key, findPage, item) );
        }
        err = findPage->eraseItem(nsIndex, datatype, key);
        if (err == ESP_ERR_FLASH_OP_FAIL) {
            return ESP_ERR_NVS_REMOVE_FAILED;
        }
        if (err != ESP_OK) {
            return err;
        }
    }
#ifndef ESP_PLATFORM
    debugCheck();
#endif
    return ESP_OK;
}

esp_err_t Storage::createOrOpenNamespace(const char* nsName, bool canCreate, uint8_t& nsIndex)
{
    if (mState != StorageState::ACTIVE) {
        return ESP_ERR_NVS_NOT_INITIALIZED;
    }
    auto it = std::find_if(mNamespaces.begin(), mNamespaces.end(), [=] (const NamespaceEntry& e) -> bool {
        return strncmp(nsName, e.mName, sizeof(e.mName) - 1) == 0;
    });
    if (it == std::end(mNamespaces)) {
        if (!canCreate) {
            return ESP_ERR_NVS_NOT_FOUND;
        }

        uint8_t ns;
        for (ns = 1; ns < 255; ++ns) {
            if (mNamespaceUsage.get(ns) == false) {
                break;
            }
        }

        if (ns == 255) {
            return ESP_ERR_NVS_NOT_ENOUGH_SPACE;
        }

        auto err = writeItem(Page::NS_INDEX, ItemType::U8, nsName, &ns, sizeof(ns));
        if (err != ESP_OK) {
            return err;
        }
        mNamespaceUsage.set(ns, true);
        nsIndex = ns;

        NamespaceEntry* entry = new NamespaceEntry;
        entry->mIndex = ns;
        strncpy(entry->mName, nsName, sizeof(entry->mName) - 1);
        entry->mName[sizeof(entry->mName) - 1] = 0;
        mNamespaces.push_back(entry);

    } else {
        nsIndex = it->mIndex;
    }
    return ESP_OK;
}

esp_err_t Storage::readItem(uint8_t nsIndex, ItemType datatype, const char* key, void* data, size_t dataSize)
{
    if (mState != StorageState::ACTIVE) {
        return ESP_ERR_NVS_NOT_INITIALIZED;
    }

    Item item;
    Page* findPage = nullptr;
    auto err = findItem(nsIndex, datatype, key, findPage, item);
    if (err != ESP_OK) {
        return err;
    }

    return findPage->readItem(nsIndex, datatype, key, data, dataSize);
}

esp_err_t Storage::eraseItem(uint8_t nsIndex, ItemType datatype, const char* key)
{
    if (mState != StorageState::ACTIVE) {
        return ESP_ERR_NVS_NOT_INITIALIZED;
    }

    Item item;
    Page* findPage = nullptr;
    auto err = findItem(nsIndex, datatype, key, findPage, item);
    if (err != ESP_OK) {
        return err;
    }

    return findPage->eraseItem(nsIndex, datatype, key);
}

esp_err_t Storage::eraseNamespace(uint8_t nsIndex)
{
    if (mState != StorageState::ACTIVE) {
        return ESP_ERR_NVS_NOT_INITIALIZED;
    }

    for (auto it = std::begin(mPageManager); it != std::end(mPageManager); ++it) {
        while (true) {
            auto err = it->eraseItem(nsIndex, ItemType::ANY, nullptr);
            if (err == ESP_ERR_NVS_NOT_FOUND) {
                break;
            }
            else if (err != ESP_OK) {
                return err;
            }
        }
    }
    return ESP_OK;

}

esp_err_t Storage::getItemDataSize(uint8_t nsIndex, ItemType datatype, const char* key, size_t& dataSize)
{
    if (mState != StorageState::ACTIVE) {
        return ESP_ERR_NVS_NOT_INITIALIZED;
    }

    Item item;
    Page* findPage = nullptr;
    auto err = findItem(nsIndex, datatype, key, findPage, item);
    if (err != ESP_OK) {
        return err;
    }

    dataSize = item.varLength.dataSize;
    return ESP_OK;
}

void Storage::debugDump()
{
    for (auto p = mPageManager.begin(); p != mPageManager.end(); ++p) {
        p->debugDump();
    }
}

#ifndef ESP_PLATFORM
void Storage::debugCheck()
{
    std::map<std::string, Page*> keys;
    
    for (auto p = mPageManager.begin(); p != mPageManager.end(); ++p) {
        size_t itemIndex = 0;
        size_t usedCount = 0;
        Item item;
        while (p->findItem(Page::NS_ANY, ItemType::ANY, nullptr, itemIndex, item) == ESP_OK) {
            std::stringstream keyrepr;
            keyrepr << static_cast<unsigned>(item.nsIndex) << "_" << static_cast<unsigned>(item.datatype) << "_" << item.key;
            std::string keystr = keyrepr.str();
            if (keys.find(keystr) != std::end(keys)) {
                printf("Duplicate key: %s\n", keystr.c_str());
                debugDump();
                assert(0);
            }
            keys.insert(std::make_pair(keystr, static_cast<Page*>(p)));
            itemIndex += item.span;
            usedCount += item.span;
        }
        assert(usedCount == p->getUsedEntryCount());
    }
}
#endif //ESP_PLATFORM

}