require 'libhtkio'
require 'speech_utils'
local TNetReader = nerv.class("nerv.TNetReader", "nerv.DataReader")

function TNetReader:__init(global_conf, reader_conf)
    self.feat_id = reader_conf.id
    self.frm_ext = reader_conf.frm_ext
    self.gconf = global_conf
    self.global_transf = reader_conf.global_transf
    self.debug = global_conf.debug
    if self.debug == nil then
        self.debug = false
    end
    self.feat_repo = nerv.TNetFeatureRepo(reader_conf.scp_file,
                                          reader_conf.conf_file,
                                          reader_conf.frm_ext)
    self.lab_repo = {}
    for id, mlf_spec in pairs(reader_conf.mlfs) do
        self.lab_repo[id] = nerv.TNetLabelRepo(mlf_spec.file,
                                            mlf_spec.format,
                                            mlf_spec.format_arg,
                                            mlf_spec.dir,
                                            mlf_spec.ext)
    end
end

function TNetReader:get_data()
    if self.feat_repo:is_end() then
        return nil
    end
    local res = {}
    local frm_ext = self.frm_ext
    local step = frm_ext * 2 + 1
    -- read HTK feature
    local feat_utter = self.feat_repo:cur_utter(self.debug)
    -- global transf
    local transformed = nerv.speech_utils.global_transf(feat_utter,
                            self.global_transf, frm_ext, self.gconf)

    res[self.feat_id] = transformed
    -- add corresponding labels
    for id, repo in pairs(self.lab_repo) do
        local lab_utter = repo:get_utter(self.feat_repo,
                                        transformed:nrow(),
                                        self.debug)
        res[id] = lab_utter
    end
    -- move the pointer to next
    self.feat_repo:next()
    collectgarbage("collect")
    return res
end