-- ===================================================================
-- /unix-storage.lua
-- Persistent storage in /data using Serpent Serializer
-- Unix systems only

modpol.datadir     = modpol.topdir  .. "/data"
modpol.file_ledger = modpol.datadir .. "/ledger.dat"
modpol.file_orgs   = modpol.datadir .. "/orgs.dat"

os.execute ("mkdir -p " .. modpol.datadir)

modpol.ocutil.setlogdir  (modpol.datadir)
modpol.ocutil.setlogname ("modpol.log")

modpol.serpent = {}
dofile (modpol.topdir .. "/util/serpent/serpent.lua")

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

local write_file = function(path, data)
    local file, err
    file, err = io.open(path, "w")
    if err then print(err) os.exit(1) end
    file:write(data)
    file:close()
end

local read_file = function(path)
    local file, err
    file, err = io.open(path, "r")
    if err then return nil end
    local data = file:read()
    file:close()
    return data
end

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

local store_ledger = function(verbose)
    local serialized_ledger = modpol.serpent.dump(modpol.ledger)
    write_file(modpol.file_ledger, serialized_ledger)

    local count = 0
    for _ in pairs(modpol.ledger) do count = count + 1 end

    if verbose then modpol.ocutil.log(count .. " ledger entries stored to disk")
end

local store_orgs = function(verbose)
    local serialized_orgs = modpol.serpent.dump(modpol.orgs)
    write_file(modpol.file_orgs, serialized_orgs)

    local count = 0
    for _ in pairs(modpol.orgs.array) do count = count + 1 end

    if verbose then modpol.ocutil.log(count .. " orgs stored to disk")
end

modpol.store_data = function(verbose)
    store_ledger(verbose)
    store_orgs(verbose)
end

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

local load_ledger = function()
    local obj = read_file(modpol.file_ledger)
    if obj ~= nil then
        local func, err = load(obj)
        if err then
            modpol.ocutil.log("Error loading ledger data")
            os.exit(1)
        end
        modpol.ledger = func()
        
        local count = 0
        for _ in pairs(modpol.ledger) do count = count + 1 end

        modpol.ocutil.log(count .. " ledger entries loaded from disk")
    else
        modpol.ocutil.log("No stored ledger data found")
    end
end

local load_orgs = function()
    local obj = read_file(modpol.file_orgs)
    if obj ~= nil then
        local func, err = load(obj)
        if err then 
            modpol.ocutil.log("Error loading org data")
            os.exit(1)
        end
        modpol.orgs = func()

        local count = 0
        for _ in pairs(modpol.orgs.array) do count = count + 1 end

        modpol.ocutil.log(count .. " orgs loaded from disk")
    else
        modpol.ocutil.log("No stored orgs found")
    end
end

modpol.load_storage = function()
    load_ledger()
    load_orgs()
end