-- server/shop.lua
print("^2[turfwar]^7 server/shop.lua loaded (shop purchases + police support + DB gang bank + anti-doublefire + oxmysql-safe)")

Config = Config or {}
Config.Shops = Config.Shops or {}

local POLICE_GANG_ID = 3

-- DB table
local GANG_TABLE   = "turfwar_gang_accounts"
local COL_GANG_ID  = "gang_id"
local COL_BALANCE  = "balance"

-- Debug toggle: set Config.Shops.Debug = true
local function D(msg)
    if Config and Config.Shops and Config.Shops.Debug then
        print("^3[turfwar:shop]^7 " .. msg)
    end
end

-- =========================================================
-- Gang tracking
-- =========================================================
local playerGang = {} -- [src] = gangId

-- =========================================================
-- Time helper (must be defined before used)
-- =========================================================
local function nowMs()
    return GetGameTimer()
end

-- =========================================================
-- Gang sync handshake state (must be defined before used)
-- =========================================================
local freshSync = {}   -- [src] = lastGameTimerMs
local pendingBuy = {}  -- [src] = { nonce, kind, itemId }
local GANG_SYNC_TTL_MS = 2000


local function SetGangFor(src, gangId)
    playerGang[src] = tonumber(gangId) or 0
end

local function GetPlayerGangId(src)
    return tonumber(playerGang[src]) or 0
end

RegisterNetEvent("turfwar:setFaction", function(gangId)
    local src = source
    SetGangFor(src, gangId)
    freshSync[src] = nowMs()
end)

RegisterNetEvent("turfwar:gangUpdate", function(gangId)
    local src = source
    SetGangFor(src, gangId)
    freshSync[src] = nowMs()
end)

RegisterNetEvent("turfwar:setMyGang", function(gangId)
    local src = source
    SetGangFor(src, gangId)
    freshSync[src] = nowMs()
end)


-- =========================================================
-- Gang sync handshake
-- =========================================================
local freshSync = {}   -- [src] = lastGameTimerMs
local pendingBuy = {}  -- [src] = { nonce, kind, itemId }
local GANG_SYNC_TTL_MS = 2000

local function nowMs()
    return GetGameTimer()
end

local function isGangSyncFresh(src)
    local t = freshSync[src]
    return t and (nowMs() - t) <= GANG_SYNC_TTL_MS
end

local function requestGangSync(src, nonce)
    TriggerClientEvent("turfwar:shop:syncGangRequest", src, nonce)
end

-- =========================================================
-- Anti-doublefire / anti-overlap
-- =========================================================
local inFlight = {} -- [src] = true
local seen = {}     -- seen[src][key] = expireMs
local SEEN_TTL_MS = 800

local function seenKey(src, kind, itemId)
    local bucket = math.floor(nowMs() / 250)
    return ("%d|%s|%s|%d"):format(src, kind, tostring(itemId or ""), bucket)
end

local function isSeen(src, key)
    local t = seen[src]
    if not t then return false end
    local exp = t[key]
    if not exp then return false end
    if exp < nowMs() then
        t[key] = nil
        return false
    end
    return true
end

local function markSeen(src, key)
    seen[src] = seen[src] or {}
    seen[src][key] = nowMs() + SEEN_TTL_MS
end

local function clearSrcState(src)
    playerGang[src] = nil
    freshSync[src] = nil
    pendingBuy[src] = nil
    inFlight[src] = nil
    seen[src] = nil
end

AddEventHandler("playerDropped", function()
    clearSrcState(source)
end)

-- =========================================================
-- Shop tables (police vs gangs)
-- =========================================================
local function GetShopTablesForGang(gangId)
    local s = Config.Shops or {}
    if gangId == POLICE_GANG_ID then
        return s.PoliceWeapons or {}, s.PoliceAmmo or {}, s.PoliceVehicles or {}, true
    end
    return s.Weapons or {}, s.Ammo or {}, s.Vehicles or {}, false
end

-- =========================================================
-- DB Adapter (oxmysql or mysql-async) - FIXED normalize affectedRows
-- =========================================================
local function have_oxmysql()
    return GetResourceState("oxmysql") == "started" and exports.oxmysql ~= nil
end

local function have_mysql_async()
    return MySQL and MySQL.Async and MySQL.Async.fetchScalar ~= nil
end

local function normalizeAffected(result)
    -- oxmysql sometimes returns a table, mysql-async usually returns number
    if type(result) == "number" then
        return result
    end
    if type(result) == "table" then
        -- common oxmysql shapes:
        -- { affectedRows = 1, changedRows = 1, insertId = 0 }
        if result.affectedRows ~= nil then return tonumber(result.affectedRows) or 0 end
        if result.changedRows  ~= nil then return tonumber(result.changedRows)  or 0 end

        -- sometimes wrapped in array:
        if result[1] and type(result[1]) == "table" then
            if result[1].affectedRows ~= nil then return tonumber(result[1].affectedRows) or 0 end
            if result[1].changedRows  ~= nil then return tonumber(result[1].changedRows)  or 0 end
        end
    end
    return 0
end

local function db_fetchScalar(query, params, cb)
    if have_oxmysql() then
        exports.oxmysql:scalar(query, params, cb)
        return
    end
    if have_mysql_async() then
        MySQL.Async.fetchScalar(query, params, cb)
        return
    end
    print("^1[turfwar]^7 ERROR: No SQL adapter found. Start oxmysql or mysql-async.")
    cb(nil)
end

local function db_execute(query, params, cb)
    if have_oxmysql() then
        exports.oxmysql:execute(query, params, function(result)
            cb(normalizeAffected(result))
        end)
        return
    end
    if have_mysql_async() then
        MySQL.Async.execute(query, params, function(affected)
            cb(normalizeAffected(affected))
        end)
        return
    end
    print("^1[turfwar]^7 ERROR: No SQL adapter found. Start oxmysql or mysql-async.")
    cb(0)
end

-- =========================================================
-- Gang bank: balance + atomic charge
-- =========================================================
local function ensureGangRow(gangId)
    -- NOTE: ON DUPLICATE KEY requires UNIQUE KEY on gang_id.
    -- You *should* add: ALTER TABLE turfwar_gang_accounts ADD UNIQUE KEY uq_gang_id (gang_id);
    local q = ("INSERT INTO %s (%s,%s) VALUES (?,0) ON DUPLICATE KEY UPDATE %s=%s")
        :format(GANG_TABLE, COL_GANG_ID, COL_BALANCE, COL_GANG_ID, COL_GANG_ID)
    db_execute(q, { gangId }, function(_) end)
end

local function GetGangBalanceAsync(gangId, cb)
    ensureGangRow(gangId)
    local q = ("SELECT %s FROM %s WHERE %s = ? LIMIT 1")
        :format(COL_BALANCE, GANG_TABLE, COL_GANG_ID)
    db_fetchScalar(q, { gangId }, function(val)
        cb(tonumber(val) or 0)
    end)
end

local function TryChargeGangAsync(gangId, amount, cb)
    ensureGangRow(gangId)
    amount = tonumber(amount) or 0
    if amount <= 0 then
        GetGangBalanceAsync(gangId, function(bal) cb(true, bal) end)
        return
    end

    local q = ("UPDATE %s SET %s = %s - ? WHERE %s = ? AND %s >= ?")
        :format(GANG_TABLE, COL_BALANCE, COL_BALANCE, COL_GANG_ID, COL_BALANCE)

    db_execute(q, { amount, gangId, amount }, function(affected)
        affected = tonumber(affected) or 0
        D(("UPDATE affectedRows=%d gang=%d amount=%d"):format(affected, gangId, amount))

        if affected > 0 then
            GetGangBalanceAsync(gangId, function(newBal) cb(true, newBal) end)
        else
            GetGangBalanceAsync(gangId, function(bal) cb(false, bal) end)
        end
    end)
end

-- =========================================================
-- Balance request
-- =========================================================
RegisterNetEvent("turfwar:shop:requestBalance", function()
    local src = source
    local gangId = GetPlayerGangId(src)

    if gangId == POLICE_GANG_ID then
        TriggerClientEvent("turfwar:shop:balance", src, gangId, 0)
        return
    end

    GetGangBalanceAsync(gangId, function(bal)
        TriggerClientEvent("turfwar:shop:balance", src, gangId, bal)
    end)
end)

-- =========================================================
-- Finish helper
-- =========================================================
local function Finish(src, ok, message, newBal)
    TriggerClientEvent("turfwar:shop:result", src, ok, message or "", newBal)
    inFlight[src] = nil
end

-- =========================================================
-- Purchase cores
-- =========================================================
local function HandleBuyWeapon(src, gangId, itemId)
    itemId = tostring(itemId or "")

    if gangId == 0 then
        Finish(src, false, "You are not in a gang.", nil)
        return
    end

    local weapons, _, _, isPolice = GetShopTablesForGang(gangId)
    local item = weapons[itemId]
    if type(item) ~= "table" then
        Finish(src, false, "Invalid weapon.", nil)
        return
    end

    local price = tonumber(item.price) or 0

    if isPolice or price <= 0 then
        TriggerClientEvent("turfwar:shop:grantWeapon", src, item.weapon, item.ammo or 0)
        Finish(src, true, ("Issued %s"):format(item.label or "item"), 0)
        return
    end

    TryChargeGangAsync(gangId, price, function(ok, newBal)
        D(("CHARGE weapon src=%d gang=%d price=%d ok=%s newBal=%d item=%s"):format(
            src, gangId, price, tostring(ok), tonumber(newBal) or -1, itemId
        ))

        if not ok then
            Finish(src, false, "Not enough gang funds.", newBal)
            return
        end


        TriggerClientEvent("turfwar:shop:grantWeapon", src, item.weapon, item.ammo or 0)
        Finish(src, true, ("Purchased %s"):format(item.label or "item"), newBal)
    end)
end

local function HandleBuyAmmo(src, gangId, itemId)
    itemId = tostring(itemId or "")

    if gangId == 0 then
        Finish(src, false, "You are not in a gang.", nil)
        return
    end

    local _, ammo, _, isPolice = GetShopTablesForGang(gangId)
    local item = ammo[itemId]
    if type(item) ~= "table" then
        Finish(src, false, "Invalid ammo.", nil)
        return
    end

    local price = tonumber(item.price) or 0

    if isPolice or price <= 0 then
        TriggerClientEvent("turfwar:shop:grantAmmo", src, item.forWeapon, item.amount or 0)
        Finish(src, true, ("Issued %s"):format(item.label or "ammo"), 0)
        return
    end

    TryChargeGangAsync(gangId, price, function(ok, newBal)
        D(("CHARGE ammo src=%d gang=%d price=%d ok=%s newBal=%d item=%s"):format(
            src, gangId, price, tostring(ok), tonumber(newBal) or -1, itemId
        ))

        if not ok then
            Finish(src, false, "Not enough gang funds.", newBal)
            return
        end


        TriggerClientEvent("turfwar:shop:grantAmmo", src, item.forWeapon, item.amount or 0)
        Finish(src, true, ("Purchased %s"):format(item.label or "ammo"), newBal)
    end)
end

local function HandleBuyVehicle(src, gangId, itemId)
    itemId = tostring(itemId or "")

    if gangId == 0 then
        Finish(src, false, "You are not in a gang.", nil)
        return
    end

    local _, _, vehicles, isPolice = GetShopTablesForGang(gangId)
    local item = vehicles[itemId]
    if type(item) ~= "table" then
        Finish(src, false, "Invalid vehicle.", nil)
        return
    end

    local price = tonumber(item.price) or 0

    if isPolice or price <= 0 then
        TriggerClientEvent("turfwar:shop:grantVehicle", src, item.model)
        Finish(src, true, ("Issued %s"):format(item.label or "vehicle"), 0)
        return
    end

    TryChargeGangAsync(gangId, price, function(ok, newBal)
        D(("CHARGE vehicle src=%d gang=%d price=%d ok=%s newBal=%d item=%s"):format(
            src, gangId, price, tostring(ok), tonumber(newBal) or -1, itemId
        ))

        if not ok then
            Finish(src, false, "Not enough gang funds.", newBal)
            return
        end


        TriggerClientEvent("turfwar:shop:grantVehicle", src, item.model)
        Finish(src, true, ("Purchased %s"):format(item.label or "vehicle"), newBal)
    end)
end

local function Execute(src, gangId, kind, itemId)
    D(("EXEC src=%d gang=%d kind=%s item=%s"):format(src, gangId, tostring(kind), tostring(itemId)))
    if kind == "weapon" then
        HandleBuyWeapon(src, gangId, itemId)
    elseif kind == "ammo" then
        HandleBuyAmmo(src, gangId, itemId)
    elseif kind == "vehicle" then
        HandleBuyVehicle(src, gangId, itemId)
    else
        Finish(src, false, "Invalid purchase.", nil)
    end
end

local function BeginPurchase(src, kind, itemId)
    local key = seenKey(src, kind, itemId)

    if isSeen(src, key) then
        D(("IGNORED DUPLICATE src=%d kind=%s item=%s"):format(src, kind, tostring(itemId)))
        return
    end
    markSeen(src, key)

    if inFlight[src] then
        D(("BLOCKED IN-FLIGHT src=%d kind=%s item=%s"):format(src, kind, tostring(itemId)))
        TriggerClientEvent("turfwar:shop:result", src, false, "Please wait…", nil)
        return
    end

    inFlight[src] = true

    if not isGangSyncFresh(src) then
        local nonce = ("%d:%d:%d"):format(src, nowMs(), math.random(100000, 999999))
        pendingBuy[src] = { nonce = nonce, kind = kind, itemId = tostring(itemId or "") }
        D(("SYNC-REQ src=%d nonce=%s kind=%s item=%s cachedGang=%d"):format(
            src, nonce, kind, tostring(itemId), GetPlayerGangId(src)
        ))
        requestGangSync(src, nonce)
        return
    end

    Execute(src, GetPlayerGangId(src), kind, itemId)
end

RegisterNetEvent("turfwar:shop:syncGangResponse", function(nonce, gangId)
    local src = source
    local p = pendingBuy[src]
    if not p or p.nonce ~= nonce then return end

    gangId = tonumber(gangId) or 0
    SetGangFor(src, gangId)
    freshSync[src] = nowMs()
    pendingBuy[src] = nil

    D(("SYNC-OK src=%d gang=%d kind=%s item=%s"):format(src, gangId, p.kind, tostring(p.itemId)))
    Execute(src, gangId, p.kind, p.itemId)
end)

RegisterNetEvent("turfwar:shop:buyWeapon", function(itemId) BeginPurchase(source, "weapon", itemId) end)
RegisterNetEvent("turfwar:shop:buyAmmo", function(itemId) BeginPurchase(source, "ammo", itemId) end)
RegisterNetEvent("turfwar:shop:buyVehicle", function(itemId) BeginPurchase(source, "vehicle", itemId) end)