package cli

import (
	"flag"
	"fmt"
	"io"
	"math"
	"os"
	"slices"
	"strings"
	"time"

	"gogs.inhome.blapointe.com/ana-ledger/src/ana"
	"gogs.inhome.blapointe.com/ana-ledger/src/ledger"
)

func Main() {
	var config Config

	fs := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
	fs.Var(&config.Files, "f", "paths to files")
	fs.Var(&config.Query.Period, "period", "period")
	fs.StringVar(&config.Query.Sort, "S", "", "sort ie date")
	fs.BoolVar(&config.Query.NoRounding, "no-rounding", false, "no rounding")
	fs.StringVar(&config.Query.With, "w", "", "regexp for transactions")
	fs.IntVar(&config.Query.Depth, "depth", 0, "depth grouping")
	fs.BoolVar(&config.Query.Normalize, "n", false, "normalize with default normalizer")
	fs.BoolVar(&config.Query.USDOnly, "usd", false, "filter to usd")
	fs.BoolVar(&config.Query.NoExchanging, "no-exchanging", true, "omit currency exchanges")
	fs.StringVar(&config.BPI, "bpi", "", "path to bpi")
	if err := fs.Parse(os.Args[1:]); err != nil {
		panic(err)
	}

	files := config.Files.Strings()
	if len(files) == 0 {
		panic("must specify at least one file")
	}
	ledgerFiles, err := ledger.NewFiles(files[0], files[1:]...)
	if err != nil {
		panic(err)
	}

	positional := fs.Args()
	if len(positional) == 0 || len(positional[0]) < 3 {
		panic("positional arguments required, ie bal|reg PATTERN MATCHING")
	}
	cmd := positional[0]

	q, err := BuildQuery(config, positional[1:])
	if err != nil {
		panic(err)
	}

	deltas, err := ledgerFiles.Deltas()
	if err != nil {
		panic(err)
	}

	if period := config.Query.Period; !period.Empty() {
		after := period.Start.Format("2006-01-02")
		before := period.Stop.Format("2006-01-02")
		deltas = deltas.Like(
			ledger.LikeAfter(after),
			ledger.LikeBefore(before),
		)
	}

	pattern := ".*"
	if depth := config.Query.Depth; depth > 0 {
		pattern = ""
		for i := 0; i < depth; i++ {
			pattern += "[^:]*:"
		}
		pattern = strings.Trim(pattern, ":")
	}
	group := ledger.GroupName(pattern)

	bpis := make(ledger.BPIs)
	if config.BPI != "" {
		b, err := ledger.NewBPIs(config.BPI)
		if err != nil {
			panic(err)
		}
		bpis = b
	}

	if config.Query.Normalize {
		deltas = ana.NewDefaultNormalizer().Normalize(deltas)
	}

	if config.Query.With != "" {
		deltas = deltas.Like(ledger.LikeWith(config.Query.With))
	}

	switch cmd[:3] {
	case "bal":
		balances := deltas.Balances().
			WithBPIs(bpis).
			KindaLike(q).
			KindaGroup(group).
			Nonzero()
		FPrintBalances(os.Stdout, "", balances, nil, config.Query.USDOnly, config.Query.Normalize, time.Now().Format("2006-01-02"))
	case "reg":
		transactions := deltas.Transactions()

		for i, transaction := range transactions {
			balances := ledger.Deltas(transaction).Like(q).Group(group).Balances().WithBPIsAt(bpis, transaction[0].Date).Nonzero()
			shouldPrint := false
			shouldPrint = shouldPrint || len(balances) > 2
			if config.Query.NoExchanging {
				shouldPrint = shouldPrint || len(balances) > 1
				for _, v := range balances {
					shouldPrint = shouldPrint || len(v) == 1
				}
			} else {
				shouldPrint = shouldPrint || len(balances) > 0
			}
			if shouldPrint {
				fmt.Printf("%s\t%s\n", transaction[0].Date, transaction[0].Description)
				FPrintBalances(os.Stdout, "\t\t", balances, transactions[:i+1].Deltas().Like(q).Group(group).Balances().WithBPIsAt(bpis, transaction[0].Date).Nonzero(), config.Query.USDOnly, config.Query.Normalize, transaction[0].Date)
			}
		}
	default:
		panic("unknown command " + positional[0])
	}
}

func FPrintBalances(w io.Writer, linePrefix string, balances, cumulatives ledger.Balances, usdOnly, normalized bool, date string) {
	maxes := map[ledger.Currency]float64{}
	keys := []string{}
	for k, v := range balances {
		keys = append(keys, k)
		for k2, v2 := range v {
			if math.Abs(v2) > math.Abs(maxes[k2]) {
				maxes[k2] = math.Abs(v2)
			}
		}
	}
	slices.Sort(keys)

	max := 0
	for _, k := range keys {
		if n := len(k); n > max {
			max = n
		}
	}

	normalizer := ana.NewDefaultNormalizer()

	format := fmt.Sprintf("%s%%-%ds\t%%s%%.2f (%%s%%.2f)\n", linePrefix, max)
	if normalized {
		format = fmt.Sprintf("%s%%-%ds\t%%s%%.2f (%%s%%.2f (%%.2f @%%.2f (%%s%%.0f)))\n", linePrefix, max)
	}
	for _, key := range keys {
		currencies := []ledger.Currency{}
		for currency := range balances[key] {
			currencies = append(currencies, currency)
		}
		slices.Sort(currencies)

		for _, currency := range currencies {
			printableCurrency := currency
			if printableCurrency != "$" {
				printableCurrency += " "
			}
			if usdOnly && printableCurrency != "$" {
				continue
			}

			cumulative := balances[key][currency]
			if balance, ok := cumulatives[key]; !ok {
			} else if value, ok := balance[currency]; !ok {
			} else {
				cumulative = value
			}

			if !normalized {
				fmt.Fprintf(w, format, key, printableCurrency, balances[key][currency], printableCurrency, cumulative)
			} else {
				factor := normalizer.NormalizeFactor(ledger.Delta{Name: key, Date: date})
				trailingMax := maxes[currency] - math.Abs(balances[key][currency])
				fmt.Fprintf(w, format, key, printableCurrency, balances[key][currency], printableCurrency, cumulative, cumulative*factor, factor, printableCurrency, factor*trailingMax)
			}
		}
	}
}