--[[ Lua has been optimised
]]

Station = Station or {} -- Add to existing table if there is one

-- Sample data record

-- 5122 ORP BR6 0SX TQ 454660 51.3735220086 0.0890385263 Orpington 3 654654 3716456 5079932 5313587 4970528 4867836

function Station.new(place)
        local this = {}
        this.num = place[1]
        this.abbr = place[2]
        this.PC = place[3]
        this.osref = place[4]
        this.lat = place[5]
        this.lng = place[6]
        this.fnme = place[7]
        this.Year_data = {}
        for k = 8,#place do
                this.Year_data[#this.Year_data+1] = place[k]
                end
        -- later ... setmetatable to add behaviour ...
        return this
        end

function Station.factory(record) -- Static method
        local fields = S_split.getyears(record,"\t")
        local place = Station.new(fields)
        return place
        end

-- =================================================================

S_split = S_split or {}

function S_split.getyears(line,delim)
        local year_table = {}
        local rest = line -- Suspect we don't need a copy (but saves destroy)
        while true do
                local pos = string.find(rest, delim, 1)
                if pos ~= nil then
                        year_table[#year_table + 1] = string.sub(rest, 1, pos - 1)
                        rest = string.sub(rest, pos + 1)
                else
                        if #rest > 1 then
                                year_table[#year_table + 1] = string.sub(rest, 1)
                        end
                        break
                end
        end
        return year_table
end

-- ===========================================================

filename = "railstats.xyz"
fh, err = io.open(filename, "r")
if err then
        print(filename.." not found")
        return
end
        print("opening "..filename.." for read")

for count = 1,2 do -- First two lines are comments
        discard = fh:read()
        -- print(discard) -- for debug purposes
        end

mystations = {} --create null table to hold results

while true do
        line = fh:read()
        if line == nil then break end
        thisStationInfo = Station.factory(line)
        mystations[#mystations+1] = thisStationInfo
        end

fh:close()
print(filename.." closed")

-- count = 0 -- test / debug helper
-- for k,v in ipairs(mystations) do
-- print(k, v.abbr, v.PC, v.fnme)
-- for i,y in ipairs (v.Year_data) do
-- print(i, y)
-- end
-- count = count + 1
-- if count > 10 then break end
-- end

for k,v in ipairs(mystations) do -- pedant would use methods in here
                                        -- defined via metatable
        if v.Year_data[#v.Year_data] ~= "NULL" then
                pass = tonumber(v.Year_data[#v.Year_data])
                if pass < 1000 then
                        print("station", v.fnme, "had", pass, "pasengers")
                end
        end
end