local QBCore = exports['qb-core']:GetCoreObject()

-- Lokale Variablen
local licenseCache = {}
local cacheTimeout = 300000 -- 5 Minuten

-- Hilfsfunktionen
local function debugPrint(message)
    if Config.Debug then
        print("^3[License-System Server] " .. message .. "^7")
    end
end

-- Spieler-Name abrufen
local function getPlayerName(src)
    local Player = QBCore.Functions.GetPlayer(src)
    if not Player then return "Unbekannt" end
    
    local charinfo = Player.PlayerData.charinfo
    if charinfo and charinfo.firstname and charinfo.lastname then
        return charinfo.firstname .. " " .. charinfo.lastname
    end
    
    return "Unbekannt"
end

-- Cache-Funktionen
local function getCachedLicense(citizenid, licenseType)
    local cacheKey = citizenid .. "_" .. licenseType
    local cached = licenseCache[cacheKey]
    
    if cached and (os.time() * 1000 - cached.timestamp) < cacheTimeout then
        debugPrint("Cache-Hit für: " .. cacheKey)
        return cached.data
    end
    
    return nil
end

local function setCachedLicense(citizenid, licenseType, data)
    local cacheKey = citizenid .. "_" .. licenseType
    licenseCache[cacheKey] = {
        data = data,
        timestamp = os.time() * 1000
    }
    debugPrint("Lizenz gecacht: " .. cacheKey)
end

-- Berechtigung prüfen
local function hasPermission(src)
    local Player = QBCore.Functions.GetPlayer(src)
    if not Player then return false end
    
    local job = Player.PlayerData.job
    if not job then return false end
    
    local hasAuth = Config.AuthorizedJobs[job.name] or false
    debugPrint("Berechtigung für " .. job.name .. ": " .. tostring(hasAuth))
    return hasAuth
end

-- Spieler-Name aus JSON extrahieren (Collation-sicher)
local function extractPlayerName(charinfo_json)
    if not charinfo_json then return "Unbekannt" end
    
    local success, charinfo = pcall(json.decode, charinfo_json)
    if success and charinfo and charinfo.firstname and charinfo.lastname then
        return charinfo.firstname .. " " .. charinfo.lastname
    end
    
    return "Unbekannt"
end

-- Sichere Datenbankoperationen mit Retry-Mechanismus
local function safeDBOperation(operation, errorMessage, maxRetries)
    maxRetries = maxRetries or 3
    local retries = 0
    
    while retries < maxRetries do
        retries = retries + 1
        local success, result = pcall(operation)
        
        if success then
            return result
        else
            debugPrint("^3DB-Retry " .. retries .. "/" .. maxRetries .. ": " .. tostring(result) .. "^7")
            if retries >= maxRetries then
                debugPrint("^1DB-Fehler: " .. (errorMessage or "Unbekannt") .. "^7")
                debugPrint("^1Details: " .. tostring(result) .. "^7")
                return nil
            end
            Wait(1000) -- 1 Sekunde warten vor Retry
        end
    end
    
    return nil
end

-- Lizenz aus Datenbank abrufen (KORRIGIERT - Collation-sicher)
local function getLicenseFromDB(citizenid, licenseType)
    debugPrint("=== getLicenseFromDB START ===")
    debugPrint("CitizenID: " .. tostring(citizenid))
    debugPrint("LicenseType: " .. tostring(licenseType))
    
    -- Cache prüfen
    local cached = getCachedLicense(citizenid, licenseType)
    if cached then
        return cached
    end
    
    -- Einfache Query ohne JOINs um Collation-Probleme zu vermeiden
    local query = [[
        SELECT * FROM player_licenses 
        WHERE citizenid = ? AND license_type = ? AND is_active = 1
        ORDER BY created_at DESC
        LIMIT 1
    ]]
    
    local result = safeDBOperation(function()
        return MySQL.query.await(query, {citizenid, licenseType})
    end, "Fehler beim Abrufen der Lizenz")
    
    if result and #result > 0 then
        local license = result[1]
        
        -- Spieler-Namen separat abrufen
        local holderQuery = "SELECT charinfo FROM players WHERE citizenid = ?"
        local holderResult = safeDBOperation(function()
            return MySQL.query.await(holderQuery, {citizenid})
        end, "Fehler beim Abrufen des Spieler-Namens")
        
        if holderResult and #holderResult > 0 then
            license.holder_name = extractPlayerName(holderResult[1].charinfo)
        else
            license.holder_name = "Unbekannt"
        end
        
        -- Aussteller-Namen separat abrufen
        if license.issued_by then
            local issuerQuery = "SELECT charinfo FROM players WHERE citizenid = ?"
            local issuerResult = safeDBOperation(function()
                return MySQL.query.await(issuerQuery, {license.issued_by})
            end, "Fehler beim Abrufen des Aussteller-Namens")
            
            if issuerResult and #issuerResult > 0 then
                license.issued_by_name = extractPlayerName(issuerResult[1].charinfo)
            else
                license.issued_by_name = "System"
            end
        else
            license.issued_by_name = "System"
        end
        
        -- Classes parsen
        if license.classes then
            local success, classes = pcall(json.decode, license.classes)
            if success and type(classes) == "table" then
                license.classes = classes
            else
                license.classes = {}
            end
        else
            license.classes = {}
        end
        
        debugPrint("Lizenz aus DB geladen: " .. license.license_type)
        
        -- In Cache speichern
        setCachedLicense(citizenid, licenseType, license)
        
        return license
    end
    
    debugPrint("Keine Lizenz in DB gefunden")
    return nil
end

-- Alle Lizenzen eines Spielers abrufen (KORRIGIERT)
local function getAllPlayerLicenses(citizenid)
    debugPrint("=== getAllPlayerLicenses START ===")
    debugPrint("CitizenID: " .. tostring(citizenid))
    
    -- Einfache Query ohne JOINs
    local query = [[
        SELECT * FROM player_licenses 
        WHERE citizenid = ? AND is_active = 1
        ORDER BY license_type, created_at DESC
    ]]
    
    local result = safeDBOperation(function()
        return MySQL.query.await(query, {citizenid})
    end, "Fehler beim Abrufen aller Lizenzen")
    
    if result and #result > 0 then
        local licenses = {}
        local seenTypes = {}
        
        -- Spieler-Namen einmal abrufen
        local holderQuery = "SELECT charinfo FROM players WHERE citizenid = ?"
        local holderResult = safeDBOperation(function()
            return MySQL.query.await(holderQuery, {citizenid})
        end, "Fehler beim Abrufen des Spieler-Namens")
        
        local holderName = "Unbekannt"
        if holderResult and #holderResult > 0 then
            holderName = extractPlayerName(holderResult[1].charinfo)
        end
        
        for _, license in ipairs(result) do
            -- Nur die neueste Lizenz pro Typ nehmen
            if not seenTypes[license.license_type] then
                seenTypes[license.license_type] = true
                
                license.holder_name = holderName
                
                -- Aussteller-Namen abrufen
                if license.issued_by then
                    local issuerQuery = "SELECT charinfo FROM players WHERE citizenid = ?"
                    local issuerResult = safeDBOperation(function()
                        return MySQL.query.await(issuerQuery, {license.issued_by})
                    end, "Fehler beim Abrufen des Aussteller-Namens")
                    
                    if issuerResult and #issuerResult > 0 then
                        license.issued_by_name = extractPlayerName(issuerResult[1].charinfo)
                    else
                        license.issued_by_name = "System"
                    end
                else
                    license.issued_by_name = "System"
                end
                
                -- Classes parsen
                if license.classes then
                    local success, classes = pcall(json.decode, license.classes)
                    if success and type(classes) == "table" then
                        license.classes = classes
                    else
                        license.classes = {}
                    end
                else
                    license.classes = {}
                end
                
                table.insert(licenses, license)
            end
        end
        
        debugPrint("Gefundene Lizenzen: " .. #licenses)
        return licenses
    end
    
    debugPrint("Keine Lizenzen gefunden")
    return {}
end

-- Lizenz in Datenbank speichern (KORRIGIERT - DateTime-Fix)
local function saveLicenseToDB(citizenid, licenseType, issuedBy, classes)
    debugPrint("=== saveLicenseToDB START ===")
    debugPrint("CitizenID: " .. tostring(citizenid))
    debugPrint("LicenseType: " .. tostring(licenseType))
    debugPrint("IssuedBy: " .. tostring(issuedBy))
    
    local config = Config.LicenseTypes[licenseType]
    if not config then
        debugPrint("^1Fehler: Unbekannter Lizenztyp: " .. licenseType .. "^7")
        return false
    end
    
    -- Spieler-Name für das name-Feld abrufen
    local holderQuery = "SELECT charinfo FROM players WHERE citizenid = ?"
    local holderResult = safeDBOperation(function()
        return MySQL.query.await(holderQuery, {citizenid})
    end, "Fehler beim Abrufen des Spieler-Namens")
    
    local holderName = "Unbekannt"
    if holderResult and #holderResult > 0 and holderResult[1].charinfo then
        holderName = extractPlayerName(holderResult[1].charinfo)
    end
    
    -- Datum berechnen
    local issueDate = os.date("%d.%m.%Y")
    local expireDate = nil
    
    if config.validity_days then
        local expireTimestamp = os.time() + (config.validity_days * 24 * 60 * 60)
        expireDate = os.date("%d.%m.%Y", expireTimestamp)
    end
    
    -- Classes zu JSON konvertieren
    local classesJson = json.encode(classes or {})
    
    -- Alte Lizenz deaktivieren
    local deactivateQuery = "UPDATE player_licenses SET is_active = 0 WHERE citizenid = ? AND license_type = ?"
    safeDBOperation(function()
        return MySQL.query.await(deactivateQuery, {citizenid, licenseType})
    end, "Fehler beim Deaktivieren alter Lizenz")
    
    -- Neue Lizenz einfügen (KORRIGIERT - DateTime als BIGINT oder korrektes Format)
    local insertQuery = [[
        INSERT INTO player_licenses 
        (citizenid, license_type, name, issue_date, expire_date, issued_by, is_active, classes, created_at) 
        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
    ]]
    
    -- created_at als BIGINT (Unix Timestamp) oder als DATETIME
    local createdAt = os.time() -- Unix Timestamp für BIGINT
    -- Alternativ für DATETIME: local createdAt = os.date("%Y-%m-%d %H:%M:%S")
    
    local insertData = {
        citizenid,
        licenseType,
        holderName,
        issueDate,
        expireDate,
        issuedBy,
        1,
        classesJson,
        createdAt
    }
    
    debugPrint("Führe INSERT-Query aus...")
    debugPrint("Daten: " .. json.encode(insertData))
    
    local result = safeDBOperation(function()
        return MySQL.insert.await(insertQuery, insertData)
    end, "Fehler beim Speichern der Lizenz")
    
    if result then
        debugPrint("Lizenz erfolgreich gespeichert. ID: " .. result)
        
        -- Cache invalidieren
        local cacheKey = citizenid .. "_" .. licenseType
        licenseCache[cacheKey] = nil
        
        return true
    else
        debugPrint("^1Fehler beim Speichern der Lizenz^7")
        return false
    end
end

-- Lizenz entziehen
local function revokeLicenseInDB(citizenid, licenseType)
    debugPrint("=== revokeLicenseInDB START ===")
    debugPrint("CitizenID: " .. tostring(citizenid))
    debugPrint("LicenseType: " .. tostring(licenseType))
    
    local query = "UPDATE player_licenses SET is_active = 0 WHERE citizenid = ? AND license_type = ? AND is_active = 1"
    
    local result = safeDBOperation(function()
        return MySQL.query.await(query, {citizenid, licenseType})
    end, "Fehler beim Entziehen der Lizenz")
    
    if result then
        debugPrint("Lizenz erfolgreich entzogen")
        
        -- Cache invalidieren
        local cacheKey = citizenid .. "_" .. licenseType
        licenseCache[cacheKey] = nil
        
        return true
    else
        debugPrint("^1Fehler beim Entziehen der Lizenz^7")
        return false
    end
end

-- Cache bereinigen
local function cleanupCache()
    local now = os.time() * 1000
    local cleaned = 0
    
    for key, cached in pairs(licenseCache) do
        if (now - cached.timestamp) > cacheTimeout then
            licenseCache[key] = nil
            cleaned = cleaned + 1
        end
    end
    
    if cleaned > 0 then
        debugPrint("Cache bereinigt: " .. cleaned .. " Einträge")
    end
end

-- Cache-Cleanup Thread
CreateThread(function()
    while true do
        Wait(300000) -- 5 Minuten
        cleanupCache()
    end
end)

-- EVENT HANDLER: Lizenz anfordern
RegisterNetEvent('license-system:server:requestLicense', function(targetId)
    local src = source
    debugPrint("=== Event: requestLicense ===")
    debugPrint("Source: " .. src .. ", Target: " .. targetId)
    
    if not hasPermission(src) then
        debugPrint("Keine Berechtigung für Spieler: " .. src)
        TriggerClientEvent('license-system:client:receiveLicense', src, nil)
        return
    end
    
    local targetPlayer = QBCore.Functions.GetPlayer(targetId)
    if not targetPlayer then
        debugPrint("Ziel-Spieler nicht gefunden: " .. targetId)
        TriggerClientEvent('license-system:client:receiveLicense', src, nil)
        return
    end
    
    local citizenid = targetPlayer.PlayerData.citizenid
    
    -- Erste verfügbare Lizenz finden
    local foundLicense = nil
    for licenseType, _ in pairs(Config.LicenseTypes) do
        local license = getLicenseFromDB(citizenid, licenseType)
        
        if license and license.is_active == 1 then
            foundLicense = {
                license = license,
                config = Config.LicenseTypes[licenseType]
            }
            break
        end
    end
    
    if foundLicense then
        debugPrint("Sende Lizenz an Client: " .. foundLicense.license.license_type)
        TriggerClientEvent('license-system:client:receiveLicense', src, foundLicense)
    else
        debugPrint("Keine aktive Lizenz gefunden")
        TriggerClientEvent('license-system:client:receiveLicense', src, nil)
    end
end)

-- EVENT HANDLER: Eigene Lizenz anfordern
RegisterNetEvent('license-system:server:requestMyLicense', function(licenseType)
    local src = source
    debugPrint("=== Event: requestMyLicense ===")
    debugPrint("Source: " .. src .. ", LicenseType: " .. licenseType)
    
    local Player = QBCore.Functions.GetPlayer(src)
    if not Player then
        debugPrint("Spieler nicht gefunden: " .. src)
        TriggerClientEvent('license-system:client:receiveMyLicense', src, nil, licenseType)
        return
    end
    
    local citizenid = Player.PlayerData.citizenid
    local license = getLicenseFromDB(citizenid, licenseType)
    
    if license and license.is_active == 1 then
        local licenseData = {
            license = license,
            config = Config.LicenseTypes[licenseType]
        }
        debugPrint("Sende eigene Lizenz an Client: " .. licenseType)
        TriggerClientEvent('license-system:client:receiveMyLicense', src, licenseData, licenseType)
    else
        debugPrint("Keine aktive eigene Lizenz gefunden: " .. licenseType)
        TriggerClientEvent('license-system:client:receiveMyLicense', src, nil, licenseType)
    end
end)

-- EVENT HANDLER: Alle Spieler-Lizenzen anfordern
RegisterNetEvent('license-system:server:requestPlayerLicenses', function(targetId)
    local src = source
    debugPrint("=== Event: requestPlayerLicenses ===")
    debugPrint("Source: " .. src .. ", Target: " .. targetId)
    
    if not hasPermission(src) then
        debugPrint("Keine Berechtigung für Spieler: " .. src)
        TriggerClientEvent('license-system:client:receivePlayerLicenses', src, {}, targetId, "Unbekannt")
        return
    end
    
    local targetPlayer = QBCore.Functions.GetPlayer(targetId)
    if not targetPlayer then
        debugPrint("Ziel-Spieler nicht gefunden: " .. targetId)
        TriggerClientEvent('license-system:client:receivePlayerLicenses', src, {}, targetId, "Unbekannt")
        return
    end
    
    local citizenid = targetPlayer.PlayerData.citizenid
    local targetName = getPlayerName(targetId)
    local licenses = getAllPlayerLicenses(citizenid)
    
    debugPrint("Sende " .. #licenses .. " Lizenzen für " .. targetName)
    TriggerClientEvent('license-system:client:receivePlayerLicenses', src, licenses, targetId, targetName)
end)

-- EVENT HANDLER: Lizenz ausstellen
RegisterNetEvent('license-system:server:issueLicense', function(targetId, licenseType, classes)
    local src = source
    debugPrint("=== Event: issueLicense ===")
    debugPrint("Source: " .. src .. ", Target: " .. targetId .. ", Type: " .. licenseType)
    
    if not hasPermission(src) then
        debugPrint("Keine Berechtigung für Spieler: " .. src)
        TriggerClientEvent('QBCore:Notify', src, Config.Notifications.no_permission.message, Config.Notifications.no_permission.type)
        return
    end
    
    local targetPlayer = QBCore.Functions.GetPlayer(targetId)
    if not targetPlayer then
        debugPrint("Ziel-Spieler nicht gefunden: " .. targetId)
        TriggerClientEvent('QBCore:Notify', src, 'Spieler nicht gefunden!', 'error')
        return
    end
    
    local issuerPlayer = QBCore.Functions.GetPlayer(src)
    if not issuerPlayer then
        debugPrint("Aussteller nicht gefunden: " .. src)
        return
    end
    
    local targetCitizenId = targetPlayer.PlayerData.citizenid
    local issuerCitizenId = issuerPlayer.PlayerData.citizenid
    
    -- Prüfen ob Lizenz bereits existiert
    local existingLicense = getLicenseFromDB(targetCitizenId, licenseType)
    
    if existingLicense and existingLicense.is_active == 1 then
        debugPrint("Lizenz bereits vorhanden und aktiv")
        TriggerClientEvent('QBCore:Notify', src, 'Spieler hat bereits eine aktive ' .. (Config.LicenseTypes[licenseType].label or licenseType) .. '!', 'error')
        return
    end
    
    -- Kosten prüfen
    local config = Config.LicenseTypes[licenseType]
    if config.price and config.price > 0 then
        if issuerPlayer.PlayerData.money.cash < config.price then
            debugPrint("Nicht genug Geld für Lizenz-Ausstellung")
            TriggerClientEvent('QBCore:Notify', src, 'Nicht genug Bargeld! Benötigt: $' .. config.price, 'error')
            return
        end
        
        -- Geld abziehen
        issuerPlayer.Functions.RemoveMoney('cash', config.price, 'license-issued')
        TriggerClientEvent('QBCore:Notify', src, 'Lizenz-Gebühr bezahlt: $' .. config.price, 'success')
    end
    
    -- Lizenz in Datenbank speichern
    local success = saveLicenseToDB(targetCitizenId, licenseType, issuerCitizenId, classes)
    
    if success then
        local targetName = getPlayerName(targetId)
        local issuerName = getPlayerName(src)
        
        debugPrint("Lizenz erfolgreich ausgestellt")
        
        -- Benachrichtigungen
        TriggerClientEvent('QBCore:Notify', src, 'Lizenz erfolgreich ausgestellt für ' .. targetName, 'success')
        TriggerClientEvent('QBCore:Notify', targetId, 'Du hast eine neue Lizenz erhalten: ' .. config.label, 'success')
        
        -- Events senden
        TriggerClientEvent('license-system:client:licenseIssued', src, targetId, licenseType)
        TriggerClientEvent('license-system:client:refreshMenu', src)
        
        -- Log
        debugPrint("Lizenz " .. licenseType .. " ausgestellt von " .. issuerName .. " für " .. targetName)
    else
        debugPrint("^1Fehler beim Ausstellen der Lizenz^7")
        TriggerClientEvent('QBCore:Notify', src, 'Fehler beim Ausstellen der Lizenz!', 'error')
    end
end)

-- EVENT HANDLER: Lizenz entziehen
RegisterNetEvent('license-system:server:revokeLicense', function(targetId, licenseType)
    local src = source
    debugPrint("=== Event: revokeLicense ===")
    debugPrint("Source: " .. src .. ", Target: " .. targetId .. ", Type: " .. licenseType)
    
    if not hasPermission(src) then
        debugPrint("Keine Berechtigung für Spieler: " .. src)
        TriggerClientEvent('QBCore:Notify', src, Config.Notifications.no_permission.message, Config.Notifications.no_permission.type)
        return
    end
    
    local targetPlayer = QBCore.Functions.GetPlayer(targetId)
    if not targetPlayer then
        debugPrint("Ziel-Spieler nicht gefunden: " .. targetId)
        TriggerClientEvent('QBCore:Notify', src, 'Spieler nicht gefunden!', 'error')
        return
    end
    
    local targetCitizenId = targetPlayer.PlayerData.citizenid
    
    -- Lizenz entziehen
    local success = revokeLicenseInDB(targetCitizenId, licenseType)
    
    if success then
        local targetName = getPlayerName(targetId)
        local issuerName = getPlayerName(src)
        local config = Config.LicenseTypes[licenseType]
        
        debugPrint("Lizenz erfolgreich entzogen")
        
        -- Benachrichtigungen
        TriggerClientEvent('QBCore:Notify', src, 'Lizenz erfolgreich entzogen von ' .. targetName, 'success')
        TriggerClientEvent('QBCore:Notify', targetId, 'Deine Lizenz wurde entzogen: ' .. (config.label or licenseType), 'error')
        
        -- Events senden
        TriggerClientEvent('license-system:client:licenseRevoked', src, targetId, licenseType)
        TriggerClientEvent('license-system:client:refreshMenu', src)
        
        -- Log
        debugPrint("Lizenz " .. licenseType .. " entzogen von " .. issuerName .. " für " .. targetName)
    else
        debugPrint("^1Fehler beim Entziehen der Lizenz^7")
        TriggerClientEvent('QBCore:Notify', src, 'Fehler beim Entziehen der Lizenz!', 'error')
    end
end)

-- EXPORT FUNKTIONEN
exports('hasLicense', function(citizenid, licenseType)
    if not citizenid or not licenseType then return false end
    
    local license = getLicenseFromDB(citizenid, licenseType)
    return license and license.is_active == 1
end)

exports('issueLicense', function(citizenid, licenseType, issuedBy, classes)
    if not citizenid or not licenseType then return false end
    
    issuedBy = issuedBy or 'system'
    return saveLicenseToDB(citizenid, licenseType, issuedBy, classes)
end)

exports('revokeLicense', function(citizenid, licenseType)
    if not citizenid or not licenseType then return false end
    
    return revokeLicenseInDB(citizenid, licenseType)
end)

exports('getPlayerLicenses', function(citizenid)
    if not citizenid then return {} end
    
    return getAllPlayerLicenses(citizenid)
end)

exports('getPlayerLicense', function(citizenid, licenseType)
    if not citizenid or not licenseType then return nil end
    
    return getLicenseFromDB(citizenid, licenseType)
end)

-- INITIALISIERUNG
CreateThread(function()
    debugPrint("License-System Server gestartet (Collation & DateTime Fix)")
    
    -- Warten bis QBCore geladen ist
    while not QBCore do
        Wait(100)
    end
    
    debugPrint("QBCore erfolgreich geladen")
    
    -- Datenbank-Verbindung testen
    local testResult = safeDBOperation(function()
        return MySQL.query.await("SELECT 1 as test")
    end, "Datenbank-Verbindungstest")
    
    if testResult then
        debugPrint("Datenbank-Verbindung erfolgreich")
    else
        debugPrint("^1Datenbank-Verbindung fehlgeschlagen^7")
    end
    
    debugPrint("License-System Server vollständig initialisiert")
end)

-- CLEANUP
AddEventHandler('onResourceStop', function(resourceName)
    if GetCurrentResourceName() == resourceName then
        debugPrint("License-System Server gestoppt")
        licenseCache = {}
    end
end)

-- DEBUG COMMANDS
RegisterCommand('licensestats', function(source, args, rawCommand)
    if source == 0 then -- Console only
        local cacheCount = 0
        for _ in pairs(licenseCache) do
            cacheCount = cacheCount + 1
        end
        
        print("=== LICENSE SYSTEM STATS ===")
        print("Cache Entries: " .. cacheCount)
        print("Config License Types: " .. (Config.LicenseTypes and #Config.LicenseTypes or 0))
        print("============================")
    end
end, true)

RegisterCommand('licenseclearcache', function(source, args, rawCommand)
    if source == 0 then -- Console only
        local oldCount = 0
        for _ in pairs(licenseCache) do
            oldCount = oldCount + 1
        end
        
        licenseCache = {}
        print("License-Cache geleert. Entfernte Einträge: " .. oldCount)
    end
end, true)

debugPrint("License-System Server vollständig geladen (Collation & DateTime Fix)")