package commands

import (
	"bufio"
	"context"
	"encoding/json"
	"fmt"
	"os"
	"strconv"
	"strings"

	"git.loyso.art/frx/eway/cmd/cli/components"
	"git.loyso.art/frx/eway/internal/entity"
	"git.loyso.art/frx/eway/internal/matcher"

	"github.com/rs/zerolog"
	"github.com/urfave/cli/v3"
)

func ItemsCommandTree() *cli.Command {
	var h itemsHandlers
	return &cli.Command{
		Name:  "items",
		Usage: "Interact with items stored inside db",
		Commands: []*cli.Command{
			newItemsGetCommand(h),
			newItemsCountCommand(h),
			newItemsUniqueParamsCommand(h),
			newItemsAggregateParametersCommand(h),
			newItemsFixSizesCommand(h),
		},
	}
}

func newItemsGetCommand(h itemsHandlers) *cli.Command {
	cmd := cli.Command{
		Name:  "get",
		Usage: "gets goods item by its id",
		Flags: []cli.Flag{
			&cli.StringFlag{
				Name:  "id",
				Usage: "id of the goods item. Either id or cart-id should be set",
			},
			&cli.IntFlag{
				Name:  "cart-id",
				Usage: "cart-id of the item. Either cart-id or id should be set",
			},
		},
	}

	return cmdWithAction(cmd, h.Get)
}

func newItemsCountCommand(h itemsHandlers) *cli.Command {
	cmd := cli.Command{
		Name:  "count",
		Usage: "iterates over collection and counts number of items",
		Flags: []cli.Flag{
			&cli.StringSliceFlag{
				Name:  "param-key-match",
				Usage: "filters by parameters with AND logic",
			},
		},
	}

	return cmdWithAction(cmd, h.Count)
}

func newItemsUniqueParamsCommand(h itemsHandlers) *cli.Command {
	cmd := cli.Command{
		Name:  "unique-params",
		Usage: "Show all stored unique param values",
		Description: "This command iterates over each item and collect keys of params in a dict and then" +
			" print it to the output. It's useful to find all unique parameters",
	}

	return cmdWithAction(cmd, h.UniqueParameters)
}

func newItemsAggregateParametersCommand(h itemsHandlers) *cli.Command {
	cmd := cli.Command{
		Name:  "aggregate-parameters",
		Usage: "Show all values of requested parameters",
		Flags: []cli.Flag{
			&cli.BoolFlag{
				Name:  "case-insensitive",
				Usage: "Ignores cases of keys",
			},
			&cli.StringSliceFlag{
				Name:  "regex",
				Usage: "Registers regex to match",
			},
			&cli.BoolFlag{
				Name:  "keys-only",
				Usage: "prints only keys",
			},
		},
	}

	return cmdWithAction(cmd, h.AggregateParameters)
}

func newItemsFixSizesCommand(h itemsHandlers) *cli.Command {
	cmd := cli.Command{
		Name:  "fix-sizes",
		Usage: "Iterates over params and sets sizes from parameters",
	}

	return cmdWithAction(cmd, h.FixSizes)
}

type itemsHandlers struct{}

func (itemsHandlers) Get(ctx context.Context, cmd *cli.Command) error {
	r, err := components.GetRepository()
	if err != nil {
		return fmt.Errorf("getting repository: %w", err)
	}

	id := cmd.String("id")
	cartID := cmd.Int("cart-id")
	if id == "" && cartID == 0 {
		return cli.Exit("oneof: id or cart-id should be set", 1)
	} else if id != "" && cartID != 0 {
		return cli.Exit("oneof: id or cart-id should be set", 1)
	}

	var item entity.GoodsItem
	if id != "" {
		item, err = r.GoodsItem().Get(ctx, id)
	} else {
		item, err = r.GoodsItem().GetByCart(ctx, cartID)
	}
	if err != nil {
		return fmt.Errorf("getting item: %w", err)
	}

	enc := json.NewEncoder(os.Stdout)
	enc.SetIndent("", " ")

	err = enc.Encode(item)
	if err != nil {
		return fmt.Errorf("encoding item: %w", err)
	}

	return nil
}

func (itemsHandlers) Count(ctx context.Context, cmd *cli.Command) error {
	r, err := components.GetRepository()
	if err != nil {
		return fmt.Errorf("getting repository: %w", err)
	}

	filters := cmd.StringSlice("param-key-match")
	m := matcher.NewRadix()
	patternMapped := make(map[string]empty, len(filters))
	if len(filters) == 0 {
		m.Register("*")
	} else {
		for _, f := range filters {
			m.Register(f)
		}
		for _, pattern := range m.Patterns() {
			patternMapped[pattern] = empty{}
		}
	}

	var count int
	items, err := r.GoodsItem().List(ctx)
	if err != nil {
		return fmt.Errorf("getting items: %w", err)
	}
	for _, item := range items {
		seenPatterns := map[string]empty{}

		for k := range item.Parameters {
			pattern := m.MatchByPattern(k)
			if pattern == "" {
				continue
			}
			if _, ok := seenPatterns[pattern]; ok {
				continue
			}
			seenPatterns[pattern] = empty{}
		}

		if len(seenPatterns) == len(patternMapped) {
			count++
		}
	}

	return nil
}

func (itemsHandlers) UniqueParameters(ctx context.Context, cmd *cli.Command) error {
	repository, err := components.GetRepository()
	if err != nil {
		return fmt.Errorf("getting repository: %w", err)
	}

	knownParams := map[string]empty{}
	iter, err := repository.GoodsItem().ListIter(ctx, 1)
	if err != nil {
		return fmt.Errorf("getting list iter: %w", err)
	}
	for item := range iter {
		for k := range item.Parameters {
			knownParams[k] = empty{}
		}
	}

	bw := bufio.NewWriter(cmd.Writer)
	for paramName := range knownParams {
		_, err = bw.WriteString(paramName + "\n")
		if err != nil {
			return fmt.Errorf("unable to write: %w", err)
		}
	}

	return bw.Flush()
}

func (itemsHandlers) AggregateParameters(ctx context.Context, cmd *cli.Command) error {
	repository, err := components.GetRepository()
	if err != nil {
		return fmt.Errorf("getting repository: %w", err)
	}
	log, err := components.GetLogger()
	if err != nil {
		return fmt.Errorf("getting logger: %w", err)
	}

	params := cmd.Args().Slice()
	opts := make([]matcher.RadixOpt, 0, 1)
	if cmd.Bool("case-insensitive") {
		opts = append(opts, matcher.RadixCaseInsensitive())
	}

	m := matcher.NewRadix(opts...)
	for _, param := range params {
		log.Debug().Str("param", param).Msg("registering param")
		m.Register(param)
	}
	for _, regexp := range cmd.StringSlice("regex") {
		log.Debug().Str("regexp", regexp).Msg("registering regexp")
		m.RegisterRegexp(regexp)
	}

	requestedValues := make(map[string]map[string]empty, len(params))
	requestedValuesByPattern := make(map[string]map[string]empty, len(params))
	iter := getItemsIter(ctx, repository.GoodsItem())
	for iter.Next() {
		item := iter.Get()
		for k, v := range item.Parameters {
			matchedPattern := m.MatchByPattern(k)
			if matchedPattern == "" {
				continue
			}

			values, ok := requestedValues[k]
			if !ok {
				values = make(map[string]empty)
			}
			values[v] = empty{}
			requestedValues[k] = values

			values, ok = requestedValuesByPattern[matchedPattern]
			if !ok {
				values = map[string]empty{}
			}
			values[v] = empty{}
			requestedValuesByPattern[matchedPattern] = values
		}
	}

	bw := bufio.NewWriter(cmd.Writer)
	_, _ = bw.WriteString("Matches:\n")

	if cmd.Bool("keys-only") {
		for k := range requestedValues {
			_, _ = bw.WriteString(k + "\n")
		}
	} else {
		for k, v := range requestedValues {
			_, _ = bw.WriteString(k + ": ")
			values := make([]string, 0, len(v))
			for item := range v {
				values = append(values, strconv.Quote(item))
			}
			valuesStr := "[" + strings.Join(values, ",") + "]\n"
			_, _ = bw.WriteString(valuesStr)
		}
	}

	_, _ = bw.WriteString("\nPatterns:\n")
	for _, pattern := range m.Patterns() {
		_, _ = bw.WriteString(pattern + "\n")
	}

	return bw.Flush()
}

func (itemsHandlers) FixSizes(ctx context.Context, cmd *cli.Command) error {
	repository, err := components.GetRepository()
	if err != nil {
		return fmt.Errorf("getting repository: %w", err)
	}

	matcher, err := components.GetDimensionMatcher()
	if err != nil {
		return fmt.Errorf("getting dimension matcher: %w", err)
	}

	dimensionDispatcher := dimensionDispatcher{m: matcher}

	log := zerolog.Ctx(ctx)

	toUpdate := make([]entity.GoodsItem, 0, 20_000)
	bus := getItemsIter(ctx, repository.GoodsItem())
	for bus.Next() {
		item := bus.Get()

		var valueBeenUpdated bool
		for key, value := range item.Parameters {
			trimmedValue := strings.TrimSpace(value)
			trimmedKey := strings.TrimSpace(key)

			if trimmedKey != key || trimmedValue != value {
				log.Warn().
					Str("old_key", key).
					Str("new_key", trimmedKey).
					Str("old_value", value).
					Str("new_value", trimmedValue).
					Msg("found mismatch")

				delete(item.Parameters, key)

				key = trimmedKey
				value = trimmedValue

				item.Parameters[key] = value
				valueBeenUpdated = true
			}

			updateValue := strings.HasSuffix(key, ":")
			if updateValue {
				key = strings.TrimSuffix(key, ":")
				item.Parameters[key] = value
				delete(item.Parameters, key+":")
				valueBeenUpdated = true
			}

			if dimensionDispatcher.dispatch(ctx, key, value, &item.Sizes) {
				valueBeenUpdated = true
				log.Debug().Str("key", key).Any("sizes", item.Sizes).Msg("been updated")
			}
		}

		var updated bool
		oldSizes := item.Sizes
		item.Sizes, updated = entity.FixupSizes(oldSizes)
		if updated {
			log.Info().Int64("cart", item.Cart).Any("old", oldSizes).Any("new", item.Sizes).Msg("sizes been fixed")
		}

		valueBeenUpdated = valueBeenUpdated || updated

		if valueBeenUpdated {
			toUpdate = append(toUpdate, item)
		}
	}
	if bus.Err() != nil {
		return fmt.Errorf("iterating: %w", bus.Err())
	}

	_, err = repository.GoodsItem().UpsertMany(ctx, toUpdate...)
	if err != nil {
		return fmt.Errorf("updating items: %w", err)
	}

	log.Info().Int("count", len(toUpdate)).Msg("updated items")

	return nil
}