package cif

import (
	"bytes"
	"encoding/json"
	"errors"
	"io"

	"git.fjla.uk/owlboard/go-types/pkg/upstreamApi"
	"git.fjla.uk/owlboard/timetable-mgr/log"
	"go.uber.org/zap"
)

// Unmarshalls data into the correct types for processing
func parseCifData(data *[]byte) (*parsedData, error) {
	log.Msg.Debug("Starting CIF Data parsing")
	if data == nil {
		return nil, errors.New("unable to parse nil pointer")
	}

	// Initialise data structures
	var parsed parsedData
	parsed.assoc = make([]upstreamApi.JsonAssociationV1, 0)
	parsed.sched = make([]upstreamApi.JsonScheduleV1, 0)

	// Create JSON Decoder
	decoder := json.NewDecoder(bytes.NewReader(*data))

	// Iterate over JSON Objects using stream decoder
	for decoder.More() {
		var obj map[string]json.RawMessage
		if err := decoder.Decode(&obj); err != nil {
			log.Msg.Error("Error decoding JSON String")
			return nil, err
		}

		// Handle parsed data
		for key, value := range obj {
			switch key {
			case "JsonTimetableV1":
				var timetable upstreamApi.JsonTimetableV1
				if err := json.Unmarshal(value, &timetable); err != nil {
					log.Msg.Error("Error decoding JSONTimetableV1 object", zap.Error(err))
					continue
				}
				parsed.header = timetable
			case "JsonAssociationV1":
				var association upstreamApi.JsonAssociationV1
				if err := json.Unmarshal(value, &association); err != nil {
					log.Msg.Error("Error decoding JSONAssociationV1 object", zap.Error(err))
					continue
				}
				parsed.assoc = append(parsed.assoc, association)
			case "JsonScheduleV1":
				var schedule upstreamApi.JsonScheduleV1
				if err := json.Unmarshal(value, &schedule); err != nil {
					log.Msg.Error("Error decoding JSONScheduleV1 object", zap.Error(err))
					continue
				}
				parsed.sched = append(parsed.sched, schedule)
			}
		}
	}
	log.Msg.Debug("CIF Parsing completed")
	return &parsed, nil
}

func parseCifDataStream(dataStream io.ReadCloser) (*parsedData, error) {
	log.Msg.Debug("STREAM-Starting CIF Datastream parsing")
	if dataStream == nil {
		return nil, errors.New("unable to parse nil pointer")
	}

	// Initialise data structures
	var parsed parsedData
	parsed.assoc = make([]upstreamApi.JsonAssociationV1, 0)
	parsed.sched = make([]upstreamApi.JsonScheduleV1, 0)

	// Create JSON Decoder
	decoder := json.NewDecoder(dataStream)

	// Iterate over JSON Objects using stream decoder
	for decoder.More() {
		var obj map[string]json.RawMessage
		if err := decoder.Decode(&obj); err != nil {
			log.Msg.Error("Error decoding JSON String")
			return nil, err
		}

		// Handle parsed data
		for key, value := range obj {
			switch key {
			case "JsonTimetableV1":
				var timetable upstreamApi.JsonTimetableV1
				if err := json.Unmarshal(value, &timetable); err != nil {
					log.Msg.Error("Error decoding JSONTimetableV1 object", zap.Error(err))
					continue
				}
				parsed.header = timetable
			case "JsonAssociationV1":
				var association upstreamApi.JsonAssociationV1
				if err := json.Unmarshal(value, &association); err != nil {
					log.Msg.Error("Error decoding JSONAssociationV1 object", zap.Error(err))
					continue
				}
				parsed.assoc = append(parsed.assoc, association)
			case "JsonScheduleV1":
				var schedule upstreamApi.JsonScheduleV1
				if err := json.Unmarshal(value, &schedule); err != nil {
					log.Msg.Error("Error decoding JSONScheduleV1 object", zap.Error(err))
					continue
				}
				parsed.sched = append(parsed.sched, schedule)
			}
		}
	}
	log.Msg.Debug("CIF Parsing completed")
	return &parsed, nil
}