-- parameters
local boss_count = 13
local drop_chance = .5
local upgrade_chance = .5
local base_ilvl = 835
local max_ilvl = 895
local over_ilvl = 880

local week_count = 26 -- 20 years
local run_count = 10000


math.randomseed(os.time())

function rollItem(base_ilvl)
    local new_ilvl = base_ilvl
    while math.random() > upgrade_chance do
        new_ilvl = new_ilvl + 5

        if new_ilvl >= max_ilvl then
            break
        end
    end
    return new_ilvl
end

function getRaidDrops(boss_count)
    local drops = 0

    for i = 1, boss_count do
        if math.random() > drop_chance then
            drops = drops + 1
        end
    end

    return drops
end

local total_over_ilvl_count = 0

local run = 1
while run <= run_count do
    local run_over_ilvl_count = 0
    local week = 1

    while week <= week_count do
        local week_drops = {}
        local week_over_ilvl_count = 0

        for i = 1, getRaidDrops(boss_count) do
            local ilvl = rollItem(base_ilvl)

            if week_drops[ilvl] == nil then
                week_drops[ilvl] = 1
            else
                week_drops[ilvl] = week_drops[ilvl] + 1
            end

            if ilvl >= over_ilvl then
                week_over_ilvl_count = week_over_ilvl_count + 1
            end
        end

    --[[
        print("week #" .. week)
        for ilvl, count in pairs(week_drops) do
            print(ilvl .. " = " .. count)
        end
        print("--")
    --]]

        week = week + 1
        run_over_ilvl_count = run_over_ilvl_count + week_over_ilvl_count
    end
    print("Week over ilvl total = " .. run_over_ilvl_count)
    total_over_ilvl_count = total_over_ilvl_count + run_over_ilvl_count
    run = run + 1
end

print("Average max ilvl = " .. (total_over_ilvl_count/run_count))