package main

import (
	"context"
	"database/sql"
	"encoding/csv"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"strconv"
	"time"
)

func ImportCSV(ctx context.Context, db *sql.DB, dir string) error {
	files, err := filepath.Glob(filepath.Join(dir, "*.csv"))
	if err != nil {
		return err
	}

	for _, fname := range files {
		fin, err := os.Open(fname)
		if err != nil {
			return fmt.Errorf("can't open file: %w", err)
		}
		defer fin.Close()

		rows, err := ReadRows(fin)
		if err != nil {
			return err
		}

		tx, err := db.BeginTx(ctx, nil)
		if err != nil {
			return err
		}

		for _, row := range rows {
			err := row.Upsert(tx)
			if err != nil {
				tx.Rollback()
				return err
			}
		}

		err = tx.Commit()
		if err != nil {
			return err
		}
	}

	return nil
}

type TwitchRevenueCSV struct {
	Date                          time.Time
	AdBreakMinutes                int
	AdTimeSecondsPerHour          float64
	AverageViewers                float64
	ChatMessages                  int
	Chatters                      int
	ClipViews                     int
	ClipsCreated                  int
	Follows                       int
	HostsAndRaidsViewers          int
	LiveViews                     int
	MaxViewers                    int
	MinutesWatched                int
	MinutesStreamed               int
	UniqueViewers                 int
	SubRevenue                    float64
	PrimeRevenue                  float64
	GiftedSubsRevenue             float64
	MultiMonthGiftedSubsRevenue   float64
	BitsRevenue                   float64
	AdRevenue                     float64
	GameSalesRevenue              float64
	ExtensionsRevenue             float64
	BountiesRevenue               float64
	PrimeSubs                     int
	TotalPaidSubs                 int
	TierOneSubs                   int
	TotalGiftedSubs               int
	GiftedTierOneSubs             int
	GiftedTierTwoSubs             int
	GiftedTierThreeSubs           int
	TotalMultiMonthGiftedSubs     int
	MultiMonthGiftedTierOneSubs   int
	MultiMonthGiftedTierTwoSubs   int
	MultiMonthGiftedTierThreeSubs int
}

func (t TwitchRevenueCSV) Upsert(tx *sql.Tx) error {
	qBytes, err := schemaFS.ReadFile("schema/insert.sql")
	if err != nil {
		return err
	}

	_, err = tx.Exec(
		string(qBytes),
		t.Date.Format(sqliteDateFormat),
		t.AdBreakMinutes,
		t.AdTimeSecondsPerHour,
		t.AverageViewers,
		t.ChatMessages,
		t.Chatters,
		t.ClipViews,
		t.ClipsCreated,
		t.Follows,
		t.HostsAndRaidsViewers,
		t.LiveViews,
		t.MaxViewers,
		t.MinutesWatched,
		t.MinutesStreamed,
		t.UniqueViewers,
		t.SubRevenue,
		t.PrimeRevenue,
		t.GiftedSubsRevenue,
		t.MultiMonthGiftedSubsRevenue,
		t.BitsRevenue,
		t.AdRevenue,
		t.GameSalesRevenue,
		t.ExtensionsRevenue,
		t.BountiesRevenue,
		t.PrimeSubs,
		t.TotalPaidSubs,
		t.TierOneSubs,
		t.TotalGiftedSubs,
		t.GiftedTierOneSubs,
		t.GiftedTierTwoSubs,
		t.GiftedTierThreeSubs,
		t.TotalMultiMonthGiftedSubs,
		t.MultiMonthGiftedTierOneSubs,
		t.MultiMonthGiftedTierTwoSubs,
		t.MultiMonthGiftedTierThreeSubs,
	)

	return err
}

func ReadRows(fin io.Reader) ([]*TwitchRevenueCSV, error) {
	var result []*TwitchRevenueCSV

	rdr := csv.NewReader(fin)

	_, err := rdr.Read() // discard header row
	if err != nil {
		return nil, err
	}
	var n = 1

	for {
		row, err := rdr.Read()
		if err != nil {
			if err == io.EOF {
				break
			}

			return nil, fmt.Errorf("can't read csv row: %w", err)
		}

		val, err := ReadFromRow(row)
		if err != nil {
			return nil, fmt.Errorf("can't parse row %d %w", n, err)
		}

		result = append(result, val)
	}

	return result, nil
}

func ReadFromRow(inp []string) (*TwitchRevenueCSV, error) {
	var (
		result TwitchRevenueCSV
		err    error
		n      int
	)

	result.Date, err = time.Parse(twitchDateFormat, inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.AdBreakMinutes, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.AdTimeSecondsPerHour, err = strconv.ParseFloat(inp[n], 64)
	if err != nil {
		return nil, err
	}
	n++
	result.AverageViewers, err = strconv.ParseFloat(inp[n], 64)
	if err != nil {
		return nil, err
	}
	n++
	result.ChatMessages, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.Chatters, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.ClipViews, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.ClipsCreated, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.Follows, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.HostsAndRaidsViewers, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.LiveViews, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.MaxViewers, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.MinutesWatched, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.MinutesStreamed, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.UniqueViewers, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.SubRevenue, err = strconv.ParseFloat(inp[n], 64)
	if err != nil {
		return nil, err
	}
	n++
	result.PrimeRevenue, err = strconv.ParseFloat(inp[n], 64)
	if err != nil {
		return nil, err
	}
	n++
	result.GiftedSubsRevenue, err = strconv.ParseFloat(inp[n], 64)
	if err != nil {
		return nil, err
	}
	n++
	result.MultiMonthGiftedSubsRevenue, err = strconv.ParseFloat(inp[n], 64)
	if err != nil {
		return nil, err
	}
	n++
	result.BitsRevenue, err = strconv.ParseFloat(inp[n], 64)
	if err != nil {
		return nil, err
	}
	n++
	result.AdRevenue, err = strconv.ParseFloat(inp[n], 64)
	if err != nil {
		return nil, err
	}
	n++
	result.GameSalesRevenue, err = strconv.ParseFloat(inp[n], 64)
	if err != nil {
		return nil, err
	}
	n++
	result.ExtensionsRevenue, err = strconv.ParseFloat(inp[n], 64)
	if err != nil {
		return nil, err
	}
	n++
	result.BountiesRevenue, err = strconv.ParseFloat(inp[n], 64)
	if err != nil {
		return nil, err
	}
	n++
	result.PrimeSubs, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.TotalPaidSubs, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.TierOneSubs, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.TotalGiftedSubs, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.GiftedTierOneSubs, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.GiftedTierTwoSubs, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.GiftedTierThreeSubs, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.TotalMultiMonthGiftedSubs, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.MultiMonthGiftedTierOneSubs, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.MultiMonthGiftedTierTwoSubs, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++
	result.MultiMonthGiftedTierThreeSubs, err = strconv.Atoi(inp[n])
	if err != nil {
		return nil, err
	}
	n++

	return &result, err
}