package common

import (
	"database/sql"
	"log"
	"time"

	qgen "git.tuxpa.in/a/gosora/query_gen"
)

var Analytics AnalyticsStore

type AnalyticsTimeRange struct {
    Quantity   int
    Unit       string
    Slices     int
    SliceWidth int
    Range      string
}

type AnalyticsStore interface {
    FillViewMap(tbl string, tr *AnalyticsTimeRange, labelList []int64, viewMap map[int64]int64, param string, args ...interface{}) (map[int64]int64, error)
}

type DefaultAnalytics struct {
}

func NewDefaultAnalytics() *DefaultAnalytics {
    return &DefaultAnalytics{}
}

/*
    rows, e := qgen.NewAcc().Select("viewchunks_systems").Columns("count,createdAt").Where("system=?").DateCutoff("createdAt", timeRange.Quantity, timeRange.Unit).Query(system)
    if e != nil && e != sql.ErrNoRows {
        return c.InternalError(e, w, r)
    }
    viewMap, e = c.AnalyticsRowsToViewMap(rows, labelList, viewMap)
    if e != nil {
        return c.InternalError(e, w, r)
    }
*/

func (s *DefaultAnalytics) FillViewMap(tbl string, tr *AnalyticsTimeRange, labelList []int64, viewMap map[int64]int64, param string, args ...interface{}) (map[int64]int64, error) {
    ac := qgen.NewAcc().Select(tbl).Columns("count,createdAt")
    if param != "" {
        ac = ac.Where(param + "=?")
    }
    rows, e := ac.DateCutoff("createdAt", tr.Quantity, tr.Unit).Query(args...)
    if e != nil && e != sql.ErrNoRows {
        return nil, e
    }
    return AnalyticsRowsToViewMap(rows, labelList, viewMap)
}

// TODO: Clamp it rather than using an offset off the current time to avoid chaotic changes in stats as adjacent sets converge and diverge?
func AnalyticsTimeRangeToLabelList(tr *AnalyticsTimeRange) (revLabelList []int64, labelList []int64, viewMap map[int64]int64) {
    viewMap = make(map[int64]int64)
    currentTime := time.Now().Unix()
    for i := 1; i <= tr.Slices; i++ {
        label := currentTime - int64(i*tr.SliceWidth)
        revLabelList = append(revLabelList, label)
        viewMap[label] = 0
    }
    labelList = append(labelList, revLabelList...)
    return revLabelList, labelList, viewMap
}

func AnalyticsRowsToViewMap(rows *sql.Rows, labelList []int64, viewMap map[int64]int64) (map[int64]int64, error) {
    defer rows.Close()
    for rows.Next() {
        var count int64
        var createdAt time.Time
        e := rows.Scan(&count, &createdAt)
        if e != nil {
            return viewMap, e
        }
        unixCreatedAt := createdAt.Unix()
        // TODO: Bulk log this
        if Dev.SuperDebug {
            log.Print("count: ", count)
            log.Print("createdAt: ", createdAt, " - ", unixCreatedAt)
        }
        for _, value := range labelList {
            if unixCreatedAt > value {
                viewMap[value] += count
                break
            }
        }
    }
    return viewMap, rows.Err()
}