【框架设计】BOSS 归属：伤害贡献与掉落分配

---BOSS 战的伤害记账
function BossDamage.onHit(actor, bossId, dmg)
    local player = class(actor)
    if not player then return end
    local key = bossId .. "_" .. actor:GetUserId()
    local rec = BossDamage.table[key]
    if not rec then
        rec = { dmg = 0, firstAt = os.time() }
        BossDamage.table[key] = rec
    end
    rec.dmg = rec.dmg + dmg
end

---归属的判定：伤害第一的队伍
function BossDamage.owner(bossId)
    local best, bestDmg = nil, 0
    local teamDmg = {}
    for key, rec in pairs(BossDamage.table) do
        local bid, uid = key:match("^(%d+)_(.+)$")
        if bid == bossId then
            local team = Team.of(uid) or uid
            teamDmg[team] = (teamDmg[team] or 0) + rec.dmg
        end
    end
    for team, dmg in pairs(teamDmg) do
        if dmg > bestDmg then
            best, bestDmg = team, dmg
        end
    end
    return best
end

---掉落的分配：模式由队长选择
local SPLIT_MODES = { "free", "round", "damage" }

function BossDrop.assign(bossId, drops)
    local owner = BossDamage.owner(bossId)
    if not owner then return end
    local mode = Team.splitMode(owner) or "free"
    for i, drop in ipairs(drops) do
        if mode == "round" then
            -- 轮流模式：按成员顺序逐件分配
            local member = Team.memberByOrder(owner, i)
            BossDrop.toMember(member, drop)
        elseif mode == "damage" then
            -- 贡献模式：按伤害占比排序分配
            local member = BossDamage.topOf(owner, i)
            BossDrop.toMember(member, drop)
        else
            BossDrop.toGround(drop)   -- 自由模式丢在地面上
        end
    end
end