local math_random = math.random

local valid_entities = {
    ['rock-big'] = true,
    ['rock-huge'] = true,
    ['sand-rock-big'] = true,
    ['mineable-wreckage'] = true
}

local size_raffle = {
    {'giant', 65, 96},
    {'huge', 33, 64},
    {'big', 17, 32},
    {'small', 9, 16},
    {'tiny', 4, 8}
}

local function get_chances()
    local chances = {}

    if game.entity_prototypes['angels-ore1'] then
        for i = 1, 6, 1 do
            table.insert(chances, {'angels-ore' .. i, 1})
        end
        table.insert(chances, {'coal', 2})
        table.insert(chances, {'mixed', 2})
        return chances
    end

    table.insert(chances, {'iron-ore', 25})
    table.insert(chances, {'copper-ore', 18})
    table.insert(chances, {'mixed', 15})
    table.insert(chances, {'coal', 14})
    table.insert(chances, {'stone', 8})
    table.insert(chances, {'uranium-ore', 3})

    return chances
end

local function set_raffle()
    global.rocks_yield_ore_veins.raffle = {}
    for _, t in pairs(get_chances()) do
        for _ = 1, t[2], 1 do
            table.insert(global.rocks_yield_ore_veins.raffle, t[1])
        end
    end

    if game.entity_prototypes['angels-ore1'] then
        global.rocks_yield_ore_veins.mixed_ores = {'angels-ore1', 'angels-ore2', 'angels-ore3', 'angels-ore4', 'angels-ore5', 'angels-ore6', 'coal'}
        return
    end

    global.rocks_yield_ore_veins.mixed_ores = {'iron-ore', 'copper-ore', 'stone', 'coal'}
end

local function get_amount(position)
    local distance_to_center = math.sqrt(position.x ^ 2 + position.y ^ 2) * 2 + 1500
    distance_to_center = distance_to_center * global.rocks_yield_ore_veins.amount_modifier
    local m = (75 + math_random(0, 50)) * 0.01
    return distance_to_center * m
end

local function draw_chain(surface, count, ore, ore_entities, ore_positions)
    local vectors = {{0, -1}, {-1, 0}, {1, 0}, {0, 1}}
    local r = math_random(1, #ore_entities)
    local position = {x = ore_entities[r].position.x, y = ore_entities[r].position.y}
    for _ = 1, count, 1 do
        table.shuffle_table(vectors)
        for i = 1, 4, 1 do
            local p = {x = position.x + vectors[i][1], y = position.y + vectors[i][2]}
            if surface.can_place_entity({name = 'coal', position = p, amount = 1}) then
                if not ore_positions[p.x .. '_' .. p.y] then
                    position.x = p.x
                    position.y = p.y
                    ore_positions[p.x .. '_' .. p.y] = true
                    local name = ore
                    if ore == 'mixed' then
                        name = global.rocks_yield_ore_veins.mixed_ores[math_random(1, #global.rocks_yield_ore_veins.mixed_ores)]
                    end
                    ore_entities[#ore_entities + 1] = {name = name, position = p, amount = get_amount(position)}
                    break
                end
            end
        end
    end
end

local function ore_vein(event)
    local surface = event.entity.surface
    local size = size_raffle[math_random(1, #size_raffle)]
    local ore = global.rocks_yield_ore_veins.raffle[math_random(1, #global.rocks_yield_ore_veins.raffle)]
    local icon
    if game.entity_prototypes[ore] then
        icon = '[img=entity/' .. ore .. ']'
    else
        icon = ' '
    end

    local player = game.players[event.player_index]
    for _, p in pairs(game.connected_players) do
        if p.index == player.index then
            p.print(
                {
                    'rocks_yield_ore_veins.player_print',
                    {'rocks_yield_ore_veins_colors.' .. ore},
                    {'rocks_yield_ore_veins.' .. size[1]},
                    {'rocks_yield_ore_veins.' .. ore},
                    icon
                },
                {r = 0.80, g = 0.80, b = 0.80}
            )
        else
            game.print(
                {
                    'rocks_yield_ore_veins.game_print',
                    '[color=' .. player.chat_color.r .. ',' .. player.chat_color.g .. ',' .. player.chat_color.b .. ']' .. player.name .. '[/color]',
                    {'rocks_yield_ore_veins.' .. size[1]},
                    {'rocks_yield_ore_veins.' .. ore},
                    icon
                },
                {r = 0.80, g = 0.80, b = 0.80}
            )
        end
    end

    local ore_entities = {{name = ore, position = {x = event.entity.position.x, y = event.entity.position.y}, amount = get_amount(event.entity.position)}}
    if ore == 'mixed' then
        ore_entities = {
            {
                name = global.rocks_yield_ore_veins.mixed_ores[math_random(1, #global.rocks_yield_ore_veins.mixed_ores)],
                position = {x = event.entity.position.x, y = event.entity.position.y},
                amount = get_amount(event.entity.position)
            }
        }
    end

    local ore_positions = {[event.entity.position.x .. '_' .. event.entity.position.y] = true}
    local count = math_random(size[2], size[3])

    for _ = 1, 128, 1 do
        local c = math_random(math.floor(size[2] * 0.25) + 1, size[2])
        if count < c then
            c = count
        end

        local placed_ore_count = #ore_entities

        draw_chain(surface, c, ore, ore_entities, ore_positions)

        count = count - (#ore_entities - placed_ore_count)

        if count <= 0 then
            break
        end
    end

    for _, e in pairs(ore_entities) do
        surface.create_entity(e)
    end
end

local function on_player_mined_entity(event)
    if not event.entity.valid then
        return
    end
    if not valid_entities[event.entity.name] then
        return
    end
    if math_random(1, global.rocks_yield_ore_veins.chance) ~= 1 then
        return
    end
    ore_vein(event)
end

local function on_init()
    global.rocks_yield_ore_veins = {}
    global.rocks_yield_ore_veins.raffle = {}
    global.rocks_yield_ore_veins.mixed_ores = {}
    global.rocks_yield_ore_veins.chance = 768
    global.rocks_yield_ore_veins.amount_modifier = 1
    set_raffle()
end

local Event = require 'utils.event'
Event.on_init(on_init)
Event.add(defines.events.on_player_mined_entity, on_player_mined_entity)