penguin/golifehk

datasources/mtr/bus/query.go

raw · 3606 bytes

package bus

import (
    "errors"
    "fmt"
    "strings"
    "github.com/tgckpg/golifehk/utils"
)

type queryObj struct {
    Route string
    BusStops *[]BusStop
    Search string
}

type qTerm struct {
    Value string
    ProblyRoute bool
}

func Query( lang string, message string ) *QueryResult {

    qo, err := parse( message )
    if err != nil {
        return &QueryResult{ Error: err }
    }

    if qo.Route != "" {

        if len( *qo.BusStops ) == 0 {
            return &QueryResult{ Error: errors.New( "Result not found" ) }
        }

        schedules, err := getSchedule( lang, qo.Route )
        if err != nil {
            return &QueryResult{ Error: err }
        }

        if len( schedules.BusStops ) == 0 {
            return &QueryResult{ Error: errors.New( "Schedules are empty. Maybe outside service time?" ) }
        }

        matches := map[BusStop] *BusStopBuses{}
        for _, busStop := range *qo.BusStops {

            for _, busStopSch := range schedules.BusStops {
                if busStopSch.BusStopId == busStop.StationId {
                    matches[busStop] = &busStopSch
                    break
                }
            }

        }

        return &QueryResult{ Lang: lang, Schedules: &matches }
    }

    return &QueryResult{ Error: errors.New( "No Result" ) }
}

func test( entry BusStop, val string ) bool {
    switch true {
    case strings.Contains( strings.ToUpper( (*entry.Name)["zh"] ), val ):
        fallthrough
    case strings.Contains( strings.ToUpper( (*entry.Name)["en"] ), val ):
        return true
    }
    return false
}

func parse( line string ) ( *queryObj, error ) {
    busStops, err := getBusStops()

    if err != nil {
        return nil, err
    }

    var route string = ""
    var searches = []string{}
    matches := []BusStop{}

    // Sanitize and assume properties for each of the keywords
    terms := []qTerm{}
    for _, val := range strings.Split( line, " " ) {
        val = strings.ToUpper( strings.Trim( val, " " ) )
        term := qTerm{
            Value: val,
            ProblyRoute: strings.ContainsAny( val, utils.ROUTE_CHARS ),
        }
        terms = append( terms, term )
    }

    // Search for route name first, otherwise search in other props
    for _, entry := range *busStops {

        // Search for RouteId
        for _, term := range terms {

            if term.ProblyRoute && term.Value == entry.RouteId {
                if route != "" && route != term.Value {
                    return nil, fmt.Errorf( "Cannot %s & %s", route, term.Value )
                }
                matches = append( matches, entry )
                route = entry.RouteId
                break 
            }

            searches = append( searches, term.Value )
            if test( entry, term.Value ) {
                matches = append( matches, entry )
                break
            }
        }
    }

    // If route found, filter out all other route
    // then search within that route
    if route != "" {
        if 0 < len( searches ) {
            matches_in := []BusStop{}
            for _, entry := range matches {
                if entry.RouteId != route {
                    continue
                }

                for _, val := range searches {
                    if test( entry, val ) {
                        matches_in = append( matches_in, entry )
                        break
                    }
                }
            }
            matches = matches_in
        } else {
        }
    }

    return &queryObj{ Route: route, BusStops: &matches }, err
}