#include <QSqlQuery>
#include <QSqlError>
#include "mailitemdao.h"
#include <QDebug>
#include <optional>

bool MailItemDao::insert(MailItem& item)
{
    QSqlDatabase db = DatabaseManager::instance().database();

    // IMAP UIDs and provider message IDs are stable across synchronizations.
    // Update the existing row instead of creating duplicates on every sync.
    if (!item.messageId().isEmpty() || item.uid() > 0) {
        QSqlQuery existing(db);
        if (!item.messageId().isEmpty()) {
            existing.prepare("SELECT id FROM MailCopy WHERE messageId = :messageId LIMIT 1");
            existing.bindValue(":messageId", item.messageId());
        } else {
            existing.prepare("SELECT id FROM MailCopy WHERE folderId = :folderId AND uid = :uid LIMIT 1");
            existing.bindValue(":folderId", item.folderId());
            existing.bindValue(":uid", item.uid());
        }
        if (existing.exec() && existing.next()) {
            item.setId(existing.value(0).toLongLong());
            return update(item);
        }
    }

    QSqlQuery query(db);
    query.prepare(
        "INSERT INTO MailCopy (folderId, messageId, subject, sender, recipient, date, read, flagged, hasAttachment, size, fileId, uid, bodyHtml, toAddr, ccAddr, bccAddr) "
        "VALUES (:folderId, :messageId, :subject, :sender, :recipient, :date, :read, :flagged, :hasAttachment, :size, :fileId, :uid, :bodyHtml, :toAddr, :ccAddr, :bccAddr)"
    );
    query.bindValue(":folderId", item.folderId());
    query.bindValue(":messageId", item.messageId().isEmpty() ? QVariant() : QVariant(item.messageId()));
    query.bindValue(":subject", item.subject());
    query.bindValue(":sender", item.sender());
    query.bindValue(":recipient", item.recipient());
    query.bindValue(":date", item.date());
    query.bindValue(":read", item.isRead() ? 1 : 0);
    query.bindValue(":flagged", item.isFlagged() ? 1 : 0);
    query.bindValue(":hasAttachment", !item.attachments().isEmpty() ? 1 : 0);
    query.bindValue(":size", item.size());
    query.bindValue(":fileId", item.fileId());
    query.bindValue(":uid", item.uid());
    query.bindValue(":bodyHtml", item.bodyHtml());
    query.bindValue(":toAddr", item.to());
    query.bindValue(":ccAddr", item.cc());
    query.bindValue(":bccAddr", item.bcc());

    if (!query.exec()) {
        qWarning() << "Failed to insert mail item:" << query.lastError().text();
        return false;
    }
    item.setId(query.lastInsertId().toLongLong());
    return true;
}

bool MailItemDao::upsert(MailItem& item)
{
    return insert(item);
}

bool MailItemDao::update(const MailItem& item)
{
    QSqlDatabase db = DatabaseManager::instance().database();
    QSqlQuery query(db);
    query.prepare(
        "UPDATE MailCopy SET "
        "folderId = :folderId, "
        "messageId = :messageId, "
        "subject = :subject, "
        "sender = :sender, "
        "recipient = :recipient, "
        "date = :date, "
        "read = :read, "
        "flagged = :flagged, "
        "hasAttachment = :hasAttachment, "
         "size = :size, "
         "fileId = :fileId, "
         "uid = :uid, "
         "bodyHtml = :bodyHtml, "
         "toAddr = :toAddr, "
         "ccAddr = :ccAddr, "
         "bccAddr = :bccAddr "
        "WHERE id = :id"
    );
    query.bindValue(":id", item.id());
    query.bindValue(":folderId", item.folderId());
    query.bindValue(":messageId", item.messageId().isEmpty() ? QVariant() : QVariant(item.messageId()));
    query.bindValue(":subject", item.subject());
    query.bindValue(":sender", item.sender());
    query.bindValue(":recipient", item.recipient());
    query.bindValue(":date", item.date());
    query.bindValue(":read", item.isRead() ? 1 : 0);
    query.bindValue(":flagged", item.isFlagged() ? 1 : 0);
    query.bindValue(":hasAttachment", !item.attachments().isEmpty() ? 1 : 0);
    query.bindValue(":size", item.size());
    query.bindValue(":fileId", item.fileId());
    query.bindValue(":uid", item.uid());
    query.bindValue(":bodyHtml", item.bodyHtml());
    query.bindValue(":toAddr", item.to());
    query.bindValue(":ccAddr", item.cc());
    query.bindValue(":bccAddr", item.bcc());

    if (!query.exec()) {
        qWarning() << "Failed to update mail item:" << query.lastError().text();
        return false;
    }
    return true;
}

bool MailItemDao::remove(qint64 id)
{
    QSqlDatabase db = DatabaseManager::instance().database();
    QSqlQuery query(db);
    query.prepare("DELETE FROM MailCopy WHERE id = :id");
    query.bindValue(":id", id);

    if (!query.exec()) {
        qWarning() << "Failed to delete mail item:" << query.lastError().text();
        return false;
    }
    return true;
}

std::optional<MailItem> MailItemDao::findById(qint64 id)
{
    QSqlDatabase db = DatabaseManager::instance().database();
    QSqlQuery query(db);
    query.prepare("SELECT id, folderId, messageId, subject, sender, recipient, date, read, flagged, hasAttachment, size, fileId, uid, bodyHtml, toAddr, ccAddr, bccAddr FROM MailCopy WHERE id = :id");
    query.bindValue(":id", id);

    if (!query.exec()) {
        qWarning() << "Failed to find mail item by id:" << query.lastError().text();
        return std::nullopt;
    }

    if (query.next()) {
        MailItem item;
        item.setId(query.value(0).toInt());
        item.setFolderId(query.value(1).toInt());
        item.setMessageId(query.value(2).toString());
        item.setSubject(query.value(3).toString());
        item.setSender(query.value(4).toString());
        item.setRecipient(query.value(5).toString());
        item.setDate(query.value(6).toDateTime());
        item.setRead(query.value(7).toBool());
        item.setFlagged(query.value(8).toBool());
        item.setSize(query.value(10).toLongLong());
        item.setFileId(query.value(11).toString());
        item.setUid(query.value(12).toLongLong());
        item.setBodyHtml(query.value(13).toString());
        item.setTo(query.value(14).toString());
        item.setCc(query.value(15).toString());
        item.setBcc(query.value(16).toString());
        QVector<QString> names;
        for (const auto &attachment : attachmentsForMail(item.id())) names.append(attachment.fileName);
        item.setAttachments(names);
        return item;
    }
    return std::nullopt;
}

QVector<MailItem> MailItemDao::findAll()
{
    QVector<MailItem> items;
    QSqlDatabase db = DatabaseManager::instance().database();
    QSqlQuery query(db);
    if (!query.exec("SELECT id, folderId, messageId, subject, sender, recipient, date, read, flagged, hasAttachment, size, fileId, uid, bodyHtml, toAddr, ccAddr, bccAddr FROM MailCopy")) {
        qWarning() << "Failed to fetch all mail items:" << query.lastError().text();
        return items;
    }

    while (query.next()) {
        MailItem item;
        item.setId(query.value(0).toInt());
        item.setFolderId(query.value(1).toInt());
        item.setMessageId(query.value(2).toString());
        item.setSubject(query.value(3).toString());
        item.setSender(query.value(4).toString());
        item.setRecipient(query.value(5).toString());
        item.setDate(query.value(6).toDateTime());
        item.setRead(query.value(7).toBool());
        item.setFlagged(query.value(8).toBool());
        item.setSize(query.value(10).toLongLong());
        item.setFileId(query.value(11).toString());
        item.setUid(query.value(12).toLongLong());
        item.setBodyHtml(query.value(13).toString());
        item.setTo(query.value(14).toString());
        item.setCc(query.value(15).toString());
        item.setBcc(query.value(16).toString());
        QVector<QString> names;
        for (const auto &attachment : attachmentsForMail(item.id())) names.append(attachment.fileName);
        item.setAttachments(names);
        items.append(item);
    }
    return items;
}

QVector<MailItem> MailItemDao::findByFolderId(int folderId)
{
    QVector<MailItem> items;
    QSqlDatabase db = DatabaseManager::instance().database();
    QSqlQuery query(db);
    query.prepare("SELECT id, folderId, messageId, subject, sender, recipient, date, read, flagged, hasAttachment, size, fileId, uid, bodyHtml, toAddr, ccAddr, bccAddr FROM MailCopy WHERE folderId = :folderId");
    query.bindValue(":folderId", folderId);

    if (!query.exec()) {
        qWarning() << "Failed to fetch mail items by folder id:" << query.lastError().text();
        return items;
    }

    while (query.next()) {
        MailItem item;
        item.setId(query.value(0).toInt());
        item.setFolderId(query.value(1).toInt());
        item.setMessageId(query.value(2).toString());
        item.setSubject(query.value(3).toString());
        item.setSender(query.value(4).toString());
        item.setRecipient(query.value(5).toString());
        item.setDate(query.value(6).toDateTime());
        item.setRead(query.value(7).toBool());
        item.setFlagged(query.value(8).toBool());
        item.setSize(query.value(10).toLongLong());
        item.setFileId(query.value(11).toString());
        item.setUid(query.value(12).toLongLong());
        item.setBodyHtml(query.value(13).toString());
        item.setTo(query.value(14).toString());
        item.setCc(query.value(15).toString());
        item.setBcc(query.value(16).toString());
        QVector<QString> names;
        for (const auto &attachment : attachmentsForMail(item.id())) names.append(attachment.fileName);
        item.setAttachments(names);
        items.append(item);
    }
    return items;
}

QVector<MailItem> MailItemDao::findByFolderIdSinceUid(int folderId, qint64 sinceUid)
{
    QVector<MailItem> items;
    QSqlDatabase db = DatabaseManager::instance().database();
    QSqlQuery query(db);
    query.prepare("SELECT id, folderId, messageId, subject, sender, recipient, date, read, flagged, hasAttachment, size, fileId, uid, bodyHtml, toAddr, ccAddr, bccAddr FROM MailCopy WHERE folderId = :folderId AND uid > :sinceUid");
    query.bindValue(":folderId", folderId);
    query.bindValue(":sinceUid", sinceUid);

    if (!query.exec()) {
        qWarning() << "Failed to fetch mail items by folder id since uid:" << query.lastError().text();
        return items;
    }

    while (query.next()) {
        MailItem item;
        item.setId(query.value(0).toInt());
        item.setFolderId(query.value(1).toInt());
        item.setMessageId(query.value(2).toString());
        item.setSubject(query.value(3).toString());
        item.setSender(query.value(4).toString());
        item.setRecipient(query.value(5).toString());
        item.setDate(query.value(6).toDateTime());
        item.setRead(query.value(7).toBool());
        item.setFlagged(query.value(8).toBool());
        item.setSize(query.value(10).toLongLong());
        item.setFileId(query.value(11).toString());
        item.setUid(query.value(12).toLongLong());
        item.setBodyHtml(query.value(13).toString());
        item.setTo(query.value(14).toString());
        item.setCc(query.value(15).toString());
        item.setBcc(query.value(16).toString());
        QVector<QString> names;
        for (const auto &attachment : attachmentsForMail(item.id())) names.append(attachment.fileName);
        item.setAttachments(names);
        items.append(item);
    }
    return items;
}

std::optional<qint64> MailItemDao::maxUidForFolder(int folderId)
{
    QSqlDatabase db = DatabaseManager::instance().database();
    QSqlQuery query(db);
    query.prepare("SELECT MAX(uid) FROM MailCopy WHERE folderId = :folderId");
    query.bindValue(":folderId", folderId);

    if (!query.exec()) {
        qWarning() << "Failed to get max uid for folder:" << query.lastError().text();
        return std::nullopt;
    }

    if (query.next()) {
        if (query.isNull(0)) {
            return std::nullopt;
        }
        return query.value(0).toLongLong();
    }
    return std::nullopt;
}

QVector<qint64> MailItemDao::getUidsForFolder(int folderId)
{
    QVector<qint64> uids;
    QSqlDatabase db = DatabaseManager::instance().database();
    QSqlQuery query(db);
    query.prepare("SELECT uid FROM MailCopy WHERE folderId = :folderId");
    query.bindValue(":folderId", folderId);

    if (!query.exec()) {
        qWarning() << "Failed to get uids for folder:" << query.lastError().text();
        return uids;
    }

    while (query.next()) {
        qint64 uid = query.value(0).toLongLong();
        uids.append(uid);
    }
    return uids;
}

QVector<qint64> MailItemDao::uidsForFolder(int folderId)
{
    return getUidsForFolder(folderId);
}

std::optional<MailItem> MailItemDao::findByUid(int folderId, qint64 uid)
{
    QSqlDatabase db = DatabaseManager::instance().database();
    QSqlQuery query(db);
    query.prepare("SELECT id FROM MailCopy WHERE folderId = :folderId AND uid = :uid LIMIT 1");
    query.bindValue(":folderId", folderId);
    query.bindValue(":uid", uid);
    if (!query.exec() || !query.next()) return std::nullopt;
    return findById(query.value(0).toLongLong());
}

bool MailItemDao::removeByUid(int folderId, qint64 uid)
{
    QSqlDatabase db = DatabaseManager::instance().database();
    QSqlQuery query(db);
    query.prepare("DELETE FROM MailCopy WHERE folderId = :folderId AND uid = :uid");
    query.bindValue(":folderId", folderId);
    query.bindValue(":uid", uid);
    if (!query.exec()) {
        qWarning() << "Failed to delete mail item by UID:" << query.lastError().text();
        return false;
    }
    return true;
}

bool MailItemDao::replaceAttachments(qint64 mailItemId,
                                     const QVector<StoredAttachmentRecord>& attachments)
{
    QSqlDatabase db = DatabaseManager::instance().database();
    if (!db.transaction()) return false;

    QSqlQuery remove(db);
    remove.prepare("DELETE FROM Attachment WHERE mailCopyId = :mailCopyId");
    remove.bindValue(":mailCopyId", mailItemId);
    if (!remove.exec()) { db.rollback(); return false; }

    QSqlQuery insert(db);
    insert.prepare("INSERT INTO Attachment (mailCopyId, filename, mimeType, size, contentId, storedPath) "
                   "VALUES (:mailCopyId, :filename, :mimeType, :size, :contentId, :storedPath)");
    for (const StoredAttachmentRecord &attachment : attachments) {
        insert.bindValue(":mailCopyId", mailItemId);
        insert.bindValue(":filename", attachment.fileName);
        insert.bindValue(":mimeType", attachment.mimeType);
        insert.bindValue(":size", attachment.size);
        insert.bindValue(":contentId", attachment.contentId);
        insert.bindValue(":storedPath", attachment.storedPath);
        if (!insert.exec()) { db.rollback(); return false; }
    }
    return db.commit();
}

QVector<StoredAttachmentRecord> MailItemDao::attachmentsForMail(qint64 mailItemId)
{
    QVector<StoredAttachmentRecord> result;
    QSqlDatabase db = DatabaseManager::instance().database();
    QSqlQuery query(db);
    query.prepare("SELECT filename, mimeType, size, contentId, storedPath "
                  "FROM Attachment WHERE mailCopyId = :mailCopyId ORDER BY id");
    query.bindValue(":mailCopyId", mailItemId);
    if (!query.exec()) return result;
    while (query.next()) {
        StoredAttachmentRecord attachment;
        attachment.fileName = query.value(0).toString();
        attachment.mimeType = query.value(1).toString();
        attachment.size = query.value(2).toLongLong();
        attachment.contentId = query.value(3).toString();
        attachment.storedPath = query.value(4).toString();
        result.append(attachment);
    }
    return result;
}

int MailItemDao::countUnreadByFolderId(int folderId)
{
    QSqlDatabase db = DatabaseManager::instance().database();
    QSqlQuery query(db);
    query.prepare("SELECT COUNT(*) FROM MailCopy WHERE folderId = :folderId AND read = 0");
    query.bindValue(":folderId", folderId);
    if (!query.exec()) {
        qWarning() << "Failed to count unread mails:" << query.lastError().text();
        return 0;
    }
    if (query.next()) {
        return query.value(0).toInt();
    }
    return 0;
}