package client

import (
	"bytes"
	"encoding/csv"
	"encoding/json"
	"fmt"
	"math"
	"reflect"
	"strconv"
	"time"

	"github.com/sosedoff/pgweb/pkg/command"
)

type Row []interface{}

type Pagination struct {
	Rows    int64 `json:"rows_count"`
	Page    int64 `json:"page"`
	Pages   int64 `json:"pages_count"`
	PerPage int64 `json:"per_page"`
}

type Result struct {
	Pagination *Pagination `json:"pagination,omitempty"`
	Columns    []string    `json:"columns"`
	Rows       []Row       `json:"rows"`
}

type Objects struct {
	Tables            []string `json:"table"`
	Views             []string `json:"view"`
	MaterializedViews []string `json:"materialized_view"`
	Sequences         []string `json:"sequence"`
}

// Due to big int number limitations in javascript, numbers should be encoded
// as strings so they could be properly loaded on the frontend.
func (res *Result) PrepareBigints() {
	for i, row := range res.Rows {
		for j, col := range row {
			if col == nil {
				continue
			}

			switch reflect.TypeOf(col).Kind() {
			case reflect.Int64:
				val := col.(int64)
				if val < -9007199254740991 || val > 9007199254740991 {
					res.Rows[i][j] = strconv.FormatInt(col.(int64), 10)
				}
			case reflect.Float64:
				val := col.(float64)

				// json.Marshal panics when dealing with NaN/Inf values
				// issue: https://github.com/golang/go/issues/25721
				if math.IsNaN(val) {
					res.Rows[i][j] = nil
					break
				}

				if val < -999999999999999 || val > 999999999999999 {
					res.Rows[i][j] = strconv.FormatFloat(val, 'e', -1, 64)
				}
			}
		}
	}
}

func (res *Result) Format() []map[string]interface{} {
	var items []map[string]interface{}

	for _, row := range res.Rows {
		item := make(map[string]interface{})

		for i, c := range res.Columns {
			item[c] = row[i]
		}

		items = append(items, item)
	}

	return items
}

func (res *Result) CSV() []byte {
	buff := &bytes.Buffer{}
	writer := csv.NewWriter(buff)

	writer.Write(res.Columns)

	for _, row := range res.Rows {
		record := make([]string, len(res.Columns))

		for i, item := range row {
			if item != nil {
				switch v := item.(type) {
				case time.Time:
					record[i] = v.Format("2006-01-02 15:04:05")
				default:
					record[i] = fmt.Sprintf("%v", item)
				}
			} else {
				record[i] = ""
			}
		}

		err := writer.Write(record)

		if err != nil {
			fmt.Println(err)
			break
		}
	}

	writer.Flush()
	return buff.Bytes()
}

func (res *Result) JSON() []byte {
	var data []byte

	if command.Opts.DisablePrettyJSON {
		data, _ = json.Marshal(res.Format())
	} else {
		data, _ = json.MarshalIndent(res.Format(), "", " ")
	}

	return data
}

func ObjectsFromResult(res *Result) map[string]*Objects {
	objects := map[string]*Objects{}

	for _, row := range res.Rows {
		schema := row[0].(string)
		name := row[1].(string)
		object_type := row[2].(string)

		if objects[schema] == nil {
			objects[schema] = &Objects{
				Tables:            []string{},
				Views:             []string{},
				MaterializedViews: []string{},
				Sequences:         []string{},
			}
		}

		switch object_type {
		case "table":
			objects[schema].Tables = append(objects[schema].Tables, name)
		case "view":
			objects[schema].Views = append(objects[schema].Views, name)
		case "materialized_view":
			objects[schema].MaterializedViews = append(objects[schema].MaterializedViews, name)
		case "sequence":
			objects[schema].Sequences = append(objects[schema].Sequences, name)
		}
	}

	return objects
}