package api

import (
	"errors"
	"fmt"
	"math"
	"path/filepath"
	"reflect"
	"strings"

	"reichard.io/antholume/database"
	"reichard.io/antholume/graph"
	"reichard.io/antholume/metadata"
)

type UTCOffset struct {
	Name  string
	Value string
}

var UTC_OFFSETS = []UTCOffset{
	{Value: "-12 hours", Name: "UTC−12:00"},
	{Value: "-11 hours", Name: "UTC−11:00"},
	{Value: "-10 hours", Name: "UTC−10:00"},
	{Value: "-9.5 hours", Name: "UTC−09:30"},
	{Value: "-9 hours", Name: "UTC−09:00"},
	{Value: "-8 hours", Name: "UTC−08:00"},
	{Value: "-7 hours", Name: "UTC−07:00"},
	{Value: "-6 hours", Name: "UTC−06:00"},
	{Value: "-5 hours", Name: "UTC−05:00"},
	{Value: "-4 hours", Name: "UTC−04:00"},
	{Value: "-3.5 hours", Name: "UTC−03:30"},
	{Value: "-3 hours", Name: "UTC−03:00"},
	{Value: "-2 hours", Name: "UTC−02:00"},
	{Value: "-1 hours", Name: "UTC−01:00"},
	{Value: "0 hours", Name: "UTC±00:00"},
	{Value: "+1 hours", Name: "UTC+01:00"},
	{Value: "+2 hours", Name: "UTC+02:00"},
	{Value: "+3 hours", Name: "UTC+03:00"},
	{Value: "+3.5 hours", Name: "UTC+03:30"},
	{Value: "+4 hours", Name: "UTC+04:00"},
	{Value: "+4.5 hours", Name: "UTC+04:30"},
	{Value: "+5 hours", Name: "UTC+05:00"},
	{Value: "+5.5 hours", Name: "UTC+05:30"},
	{Value: "+5.75 hours", Name: "UTC+05:45"},
	{Value: "+6 hours", Name: "UTC+06:00"},
	{Value: "+6.5 hours", Name: "UTC+06:30"},
	{Value: "+7 hours", Name: "UTC+07:00"},
	{Value: "+8 hours", Name: "UTC+08:00"},
	{Value: "+8.75 hours", Name: "UTC+08:45"},
	{Value: "+9 hours", Name: "UTC+09:00"},
	{Value: "+9.5 hours", Name: "UTC+09:30"},
	{Value: "+10 hours", Name: "UTC+10:00"},
	{Value: "+10.5 hours", Name: "UTC+10:30"},
	{Value: "+11 hours", Name: "UTC+11:00"},
	{Value: "+12 hours", Name: "UTC+12:00"},
	{Value: "+12.75 hours", Name: "UTC+12:45"},
	{Value: "+13 hours", Name: "UTC+13:00"},
	{Value: "+14 hours", Name: "UTC+14:00"},
}

func getUTCOffsets() []UTCOffset {
	return UTC_OFFSETS
}

func niceSeconds(input int64) (result string) {
	if input == 0 {
		return "N/A"
	}

	days := math.Floor(float64(input) / 60 / 60 / 24)
	seconds := input % (60 * 60 * 24)
	hours := math.Floor(float64(seconds) / 60 / 60)
	seconds = input % (60 * 60)
	minutes := math.Floor(float64(seconds) / 60)
	seconds = input % 60

	if days > 0 {
		result += fmt.Sprintf("%dd ", int(days))
	}
	if hours > 0 {
		result += fmt.Sprintf("%dh ", int(hours))
	}
	if minutes > 0 {
		result += fmt.Sprintf("%dm ", int(minutes))
	}
	if seconds > 0 {
		result += fmt.Sprintf("%ds", int(seconds))
	}

	return
}

func niceNumbers(input int64) string {
	if input == 0 {
		return "0"
	}

	abbreviations := []string{"", "k", "M", "B", "T"}
	abbrevIndex := int(math.Log10(float64(input)) / 3)
	scaledNumber := float64(input) / math.Pow(10, float64(abbrevIndex*3))

	if scaledNumber >= 100 {
		return fmt.Sprintf("%.0f%s", scaledNumber, abbreviations[abbrevIndex])
	} else if scaledNumber >= 10 {
		return fmt.Sprintf("%.1f%s", scaledNumber, abbreviations[abbrevIndex])
	} else {
		return fmt.Sprintf("%.2f%s", scaledNumber, abbreviations[abbrevIndex])
	}
}

// Convert Database Array -> Int64 Array
func getSVGGraphData(inputData []database.GetDailyReadStatsRow, svgWidth int, svgHeight int) graph.SVGGraphData {
	var intData []int64
	for _, item := range inputData {
		intData = append(intData, item.MinutesRead)
	}

	return graph.GetSVGGraphData(intData, svgWidth, svgHeight)
}

func dict(values ...interface{}) (map[string]interface{}, error) {
	if len(values)%2 != 0 {
		return nil, errors.New("invalid dict call")
	}
	dict := make(map[string]interface{}, len(values)/2)
	for i := 0; i < len(values); i += 2 {
		key, ok := values[i].(string)
		if !ok {
			return nil, errors.New("dict keys must be strings")
		}
		dict[key] = values[i+1]
	}
	return dict, nil
}

func fields(value interface{}) (map[string]interface{}, error) {
	v := reflect.Indirect(reflect.ValueOf(value))
	if v.Kind() != reflect.Struct {
		return nil, fmt.Errorf("%T is not a struct", value)
	}
	m := make(map[string]interface{})
	t := v.Type()
	for i := 0; i < t.NumField(); i++ {
		sv := t.Field(i)
		m[sv.Name] = v.Field(i).Interface()
	}
	return m, nil
}

func deriveBaseFileName(metadataInfo *metadata.MetadataInfo) string {
	// Derive New FileName
	var newFileName string
	if *metadataInfo.Author != "" {
		newFileName = newFileName + *metadataInfo.Author
	} else {
		newFileName = newFileName + "Unknown"
	}
	if *metadataInfo.Title != "" {
		newFileName = newFileName + " - " + *metadataInfo.Title
	} else {
		newFileName = newFileName + " - Unknown"
	}

	// Remove Slashes
	fileName := strings.ReplaceAll(newFileName, "/", "")
	return "." + filepath.Clean(fmt.Sprintf("/%s [%s]%s", fileName, *metadataInfo.PartialMD5, metadataInfo.Type))
}