--[[ Copyright (c) 2019 robot256 (MIT License)

* Project: Multiple Unit Train Control

* File: processTrainBasic.lua

* Description: Reads a train and locates locomotives to replace per the "basic" algorithm.

* Upgraded pairs must be part of a contiguous unit of locomotives (not separated by any wagons).

* Upgraded locomotives that are found with a partner will be downgraded.

--]]

function processTrainBasic(t)

local front_movers = t.locomotives["front_movers"]

local back_movers = t.locomotives["back_movers"]

-- We can only convert locomotives that are adjacent to one another

-- Make a list of contiguous units of two or more locomotives

local loco_units = {}

local unit_start = 0

local unit_end = 0

for i,c in ipairs(t.carriages) do

if unit_start == 0 then

-- Look for first locomotive in the unit, skip wagons

-- For compatibility with X-12 Nuclear Locomotive mod, x12-nuclear-tender is a fluid wagon that acts as part of a locomotive.

if c.type == "locomotive" or c.name == "x12-nuclear-tender" then

-- start unit that is length 1

unit_start = i

unit_end = i

table.insert(loco_units,{c})

end

else

-- Look for the last locomotive in the unit

if c.type == "locomotive" or c.name == "x12-nuclear-tender" then

-- update end of unit to this index

unit_end = i

table.insert(loco_units[#loco_units],c)

else

-- found wagon, close previous unit.

unit_start = 0

--local n = #loco_units

--if #loco_units[n] < 2 then

-- loco_units[n] = nil

--end

end

end

end

-- Now search each loco_unit separately

local found_pairs = {}

local upgrade_locos = {}

local unpaired_locos = {}

for _,unit in pairs(loco_units) do

-- For every front_mover, look for its twin in back_movers

for _,loco1 in pairs(front_movers) do

local loco1_here = false

for _,loco1a in pairs(unit) do

if loco1 == loco1a then

loco1_here = true

break

end

end

if loco1_here then

-- Loco1 is a front_mover in this unit

local loco1_done = false

if storage.downgrade_pairs[loco1.name] then

local mu_name = loco1.name

local std_name = storage.downgrade_pairs[mu_name]

local alt_mu_name = storage.alt_pairs[mu_name]

local alt_std_name = storage.alt_pairs[std_name]

-- Found an MU, look for its twin as an MU first

for _,loco2 in pairs(back_movers) do

if (loco2.name == mu_name or loco2.name == alt_mu_name) and (loco2.quality == loco1.quality) then

-- Potential twin, make sure it's in this unit

local loco2_here = false

for _,loco2a in pairs(unit) do

if loco2 == loco2a then

loco2_here = true

break

end

end

if loco2_here then

-- Potential twin, make sure it's not in a pair already

local loco2_free = true

for _,this_pair in pairs(found_pairs) do

if this_pair[1] == loco2 or this_pair[2] == loco2 then -- (back_mover is always 2nd member of a pair)

loco2_free = false

break

end

end

if loco2_free and checkModuleMatching(loco1,loco2) then

-- Found an MU twin, they are already a pair

--game.print("Adding pair [" .. loco1.backer_name .. ", " .. loco2.backer_name .. "]")

table.insert(found_pairs,{loco1,loco2})

loco1_done = true

break

end

end

end

end

if not loco1_done then

-- Didn't find an MU twin, look for a normal twin to this MU so we can upgrade it

for _,loco2 in pairs(back_movers) do

if (loco2.name == std_name or loco2.name == alt_std_name) and (loco2.quality == loco1.quality) then

-- Potential twin, make sure it's in this unit

local loco2_here = false

for _,loco2a in pairs(unit) do

if loco2 == loco2a then

loco2_here = true

break

end

end

if loco2_here then-- Potential twin, make sure it's not in a pair already

local loco2_free = true

for _,this_pair in pairs(found_pairs) do

if this_pair[1] == loco2 or this_pair[2] == loco2 then -- (back_mover is always 2nd member of a pair)

loco2_free = false

break

end

end

if loco2_free and checkModuleMatching(loco1,loco2) then

-- Found a normal twin, upgrade loco2

--game.print("Adding pair [" .. loco1.backer_name .. ", " .. loco2.backer_name .. "]")

table.insert(found_pairs,{loco1,loco2})

table.insert(upgrade_locos,{loco2,storage.upgrade_pairs[loco2.name]})

loco1_done = true

break

end

end

end

end

if not loco1_done then

-- Didn't find a twin to upgrade, have to downgrade this one :(

--game.print("Downgrading unpaired front mover " .. loco1.backer_name )

table.insert(upgrade_locos,{loco1,std_name})

table.insert(unpaired_locos,loco1)

end

end

elseif storage.upgrade_pairs[loco1.name] then

local std_name = loco1.name

local mu_name = storage.upgrade_pairs[std_name]

local alt_mu_name = storage.alt_pairs[mu_name]

local alt_std_name = storage.alt_pairs[std_name]

-- Found a normal, look for its twin as an MU first

for _,loco2 in pairs(back_movers) do

if (loco2.name == mu_name or loco2.name == alt_mu_name) and (loco2.quality == loco1.quality) then

-- Potential twin, make sure it's in this unit

local loco2_here = false

for _,loco2a in pairs(unit) do

if loco2 == loco2a then

loco2_here = true

break

end

end

if loco2_here then

-- Potential twin, make sure it's not in a pair already

local loco2_free = true

for _,this_pair in pairs(found_pairs) do

if this_pair[1] == loco2 or this_pair[2] == loco2 then -- (back_mover is always 2nd member of a pair)

loco2_free = false

break

end

end

if loco2_free and checkModuleMatching(loco1,loco2) then

-- Found an MU twin, upgrade loco1

--game.print("Adding pair [" .. loco1.backer_name .. ", " .. loco2.backer_name .. "]")

table.insert(found_pairs,{loco1,loco2})

table.insert(upgrade_locos,{loco1,mu_name})

loco1_done = true

break

end

end

end

end

if not loco1_done then

-- Didn't find an MU twin, look for a normal twin to this MU so we can upgrade it

for _,loco2 in pairs(back_movers) do

if (loco2.name == std_name or loco2.name == alt_std_name) and (loco2.quality == loco1.quality) then

-- Potential twin, make sure it's in this unit

local loco2_here = false

for _,loco2a in pairs(unit) do

if loco2 == loco2a then

loco2_here = true

break

end

end

if loco2_here then

-- Potential twin, make sure it's not in a pair already

local loco2_free = true

for _,this_pair in pairs(found_pairs) do

if this_pair[1] == loco2 or this_pair[2] == loco2 then -- (back_mover is always 2nd member of a pair)

loco2_free = false

break

end

end

if loco2_free and checkModuleMatching(loco1,loco2) then

-- Found a normal twin, upgrade loco1 and loco2

--game.print("Adding pair [" .. loco1.backer_name .. ", " .. loco2.backer_name .. "]")

table.insert(found_pairs,{loco1,loco2})

table.insert(upgrade_locos,{loco1,mu_name})

table.insert(upgrade_locos,{loco2,storage.upgrade_pairs[loco2.name]})

loco1_done = true

break

end

end

end

if not loco1_done then

-- if no twin for std loco1, do nothing

table.insert(unpaired_locos,loco1)

end

end

end

end

end

end

end

-- If there are any unpaired MU locos left over in back_movers, they must be downgraded!

-- Didn't find an MU twin, look for a normal twin to this MU so we can upgrade it

for _,loco2 in pairs(back_movers) do

-- Potential straggler, make sure it's not in a pair already

local loco2_free = true

for _,this_pair in pairs(found_pairs) do

if this_pair[1] == loco2 or this_pair[2] == loco2 then -- (back_mover is always 2nd member of a pair)

loco2_free = false

break

end

end

if loco2_free then

if storage.downgrade_pairs[loco2.name] then

-- Found an unpaired MU, downgrade it

--game.print("Found back straggler " .. loco2.backer_name)

table.insert(upgrade_locos,{loco2, storage.downgrade_pairs[loco2.name]})

break

end

-- record straggler

table.insert(unpaired_locos,loco2)

end

end

return found_pairs, upgrade_locos, unpaired_locos

end

return processTrainBasic