package db

import (
	"context"
	"fmt"
	"github.com/gshopify/service-wrapper/config"
	"github.com/gshopify/service-wrapper/db"
	"github.com/gshopify/service-wrapper/model"
	"github.com/gshopify/service-wrapper/server/middleware"
	"github.com/jellydator/ttlcache/v3"
	"github.com/mailru/dbr"
	_ "github.com/mailru/go-clickhouse"
	"gshopper.com/gshopify/products/graphql/generated"
	"gshopper.com/gshopify/products/relation"
	"net/url"
	"strings"
	"sync"
)

type clickhouse struct {
	ctx     context.Context
	config  *db.Config
	session *dbr.Session
	cache   *ttlcache.Cache[string, any]
}

func New(ctx context.Context, forceDebug bool) (Database, error) {
	r := &clickhouse{
		ctx:    ctx,
		config: db.New(),
		cache: ttlcache.New[string, any](
			ttlcache.WithTTL[string, any](cacheTimeout),
			ttlcache.WithCapacity[string, any](cacheCapacity),
		),
	}

	if err := config.Instance().Load(ctx, r.config); err != nil {
		return nil, err
	}

	if forceDebug {
		r.config.Params.Debug = true
	}

	//goland:noinspection HttpUrlsUsage
	source, err := url.Parse(fmt.Sprintf("http://%s:%s@%s:%d/%s",
		url.QueryEscape(r.config.Username),
		url.QueryEscape(r.config.Password),
		r.config.Host,
		r.config.Port,
		r.config.Database))
	if err != nil {
		return nil, err
	}

	kv := make(url.Values)
	kv.Set("timeout", fmt.Sprintf("%ds", r.config.Params.Timeout))
	kv.Set("read_timeout", fmt.Sprintf("%ds", r.config.Params.ReadTimeout))
	kv.Set("write_timeout", fmt.Sprintf("%ds", r.config.Params.WriteTimeout))
	kv.Set("debug", fmt.Sprintf("%v", r.config.Params.Debug))
	source.RawQuery = kv.Encode()

	con, err := dbr.Open("clickhouse", source.String(), nil)
	if err != nil {
		return nil, fmt.Errorf("could not establish Clickhouse session: %v", err)
	}

	r.session = con.NewSessionContext(ctx, nil)

	if err = r.session.Ping(); err != nil {
		return nil, err
	}

	go r.cache.Start()
	return r, nil
}

func (db *clickhouse) ProductCollections(ln model.LanguageCode, id string) ([]*generated.Collection, error) {
	var (
		collections []*generated.Collection
		key         = productCollectionKey("product.id=?", id)
		l           = ttlcache.LoaderFunc[string, any](
			func(ttl *ttlcache.Cache[string, any], _ string) *ttlcache.Item[string, any] {
				var o []relation.ProductCollection
				rows, err := db.session.SelectBySql("SELECT "+
					strings.Join(productCollectionSelection(ln), ", ")+
					" FROM `"+key.Table()+"`"+
					" ARRAY JOIN (SELECT `collections` FROM `product` WHERE `id` = ?) AS cid"+
					" WHERE `id` = cid", key.Args()...).
					Load(&o)
				if rows < 1 || err != nil {
					return nil
				}

				return ttl.Set(key.String(), o, key.TTL())
			})
	)

	if p := db.cache.Get(key.String(), ttlcache.WithLoader[string, any](l)); p != nil {
		for _, row := range p.Value().([]relation.ProductCollection) {
			collections = append(collections, row.As())
		}
	}

	return collections, nil
}

func (db *clickhouse) Product(ln model.LanguageCode, handle *string, id *string) (*generated.Product, error) {
	var (
		clause = strings.Builder{}
		vars   = []any{model.ProductStatusActive}
	)

	clause.WriteString("t.status=?")

	if id != nil {
		clause.WriteString(" AND t.id=?")
		vars = append(vars, *id)
	}

	if handle != nil {
		clause.WriteString(" AND t.handle=?")
		vars = append(vars, *handle)
	}

	var (
		key = productKey(clause.String(), vars...)
		l   = ttlcache.LoaderFunc[string, any](
			func(ttl *ttlcache.Cache[string, any], _ string) *ttlcache.Item[string, any] {
				o := relation.Product{}
				rows, err := db.session.
					Select(productSelection(ln, defaultCurrency)...).
					From(fmt.Sprintf("%s as t", key.Table())).
					LeftJoin("product_variant", "product_variant.product_id = t.id").
					LeftJoin("inventory_item", "inventory_item.id = product_variant.inventory_item_id").
					LeftJoin("inventory_level", "inventory_level.inventory_item_id = product_variant.inventory_item_id").
					Where(key.Clause(), key.Args()...).
					GroupBy("t.id").
					Limit(1).
					Load(&o)
				if rows < 1 || err != nil {
					return nil
				}

				return ttl.Set(key.String(), o, key.TTL())
			})
	)

	p := db.cache.Get(key.String(), ttlcache.WithLoader[string, any](l))
	if p == nil {
		return nil, fmt.Errorf("not found")
	}

	product := p.Value().(relation.Product)
	return product.As(), nil
}

func (db *clickhouse) ProductOptions(ln model.LanguageCode, id string) ([]*generated.ProductOption, error) {
	var (
		options []*generated.ProductOption
		key     = productOptionKey("product_id=?", id)
		l       = ttlcache.LoaderFunc[string, any](
			func(ttl *ttlcache.Cache[string, any], _ string) *ttlcache.Item[string, any] {
				var o []relation.ProductOption
				rows, err := db.session.SelectBySql("SELECT "+
					strings.Join(productOptionSelection(ln), ", ")+
					" FROM `"+key.Table()+"`"+
					" ARRAY JOIN (SELECT `options` FROM `product` WHERE `id` = ?) AS oid"+
					" WHERE `id` = oid", key.Args()).
					Load(&o)
				if rows < 1 || err != nil {
					return nil
				}

				return ttl.Set(key.String(), o, key.TTL())
			},
		)
	)

	if p := db.cache.Get(key.String(), ttlcache.WithLoader[string, any](l)); p != nil {
		for _, v := range p.Value().([]relation.ProductOption) {
			options = append(options, v.As())
		}
	}

	return options, nil
}

func (db *clickhouse) ProductVariants(ctx *middleware.GShopifyContext, id string) ([]*generated.ProductVariant, error) {
	var (
		variants []*generated.ProductVariant
		key      = productVariantKey("t.product_id=?", id)
		l        = ttlcache.LoaderFunc[string, any](
			func(ttl *ttlcache.Cache[string, any], _ string) *ttlcache.Item[string, any] {
				var o []relation.ProductVariant
				rows, err := db.session.
					Select(productVariantSelection(ctx.Language, defaultCurrency)...).
					From(fmt.Sprintf("%s as t", key.Table())).
					LeftJoin("product", "product.id = t.product_id").
					LeftJoin("inventory_item", "inventory_item.id = t.inventory_item_id").
					LeftJoin("inventory_level", "inventory_level.inventory_item_id = t.inventory_item_id").
					Where(key.Clause(), key.Args()...).
					OrderBy("position").
					GroupBy("t.id").
					Load(&o)
				if rows < 1 || err != nil {
					return nil
				}

				return ttl.Set(key.String(), o, key.TTL())
			},
		)
	)

	p := db.cache.Get(key.String(), ttlcache.WithLoader[string, any](l))
	if p != nil {
		for _, v := range p.Value().([]relation.ProductVariant) {
			variants = append(variants, v.As())
		}
	}

	return variants, nil
}

func (db *clickhouse) CollectionProducts(ln model.LanguageCode, id string) ([]*generated.Product, error) {
	var (
		products []*generated.Product
		key      = productKey("has(t.collections, ?)", id)
		l        = ttlcache.LoaderFunc[string, any](
			func(ttl *ttlcache.Cache[string, any], _ string) *ttlcache.Item[string, any] {
				var o []relation.Product
				rows, err := db.session.
					Select(productSelection(ln, defaultCurrency)...).
					From(fmt.Sprintf("%s as t", key.Table())).
					LeftJoin("product_variant", "product_variant.product_id = t.id").
					LeftJoin("inventory_item", "inventory_item.id = product_variant.inventory_item_id").
					LeftJoin("inventory_level", "inventory_level.inventory_item_id = product_variant.inventory_item_id").
					Where(key.Clause(), key.Args()...).
					GroupBy("t.id").
					Load(&o)
				if rows < 1 || err != nil {
					return nil
				}

				return ttl.Set(key.String(), o, key.TTL())
			},
		)
	)

	p := db.cache.Get(key.String(), ttlcache.WithLoader[string, any](l))
	if p == nil {
		return nil, fmt.Errorf("not found")
	}

	for _, row := range p.Value().([]relation.Product) {
		products = append(products, row.As())
	}

	return products, nil
}

func (db *clickhouse) ProductVariantOptions(ln model.LanguageCode, id string) ([]*generated.SelectedOption, error) {
	var (
		options []*generated.SelectedOption
		key     = productOptionKey("product_variant.id = ?", id)
		l       = ttlcache.LoaderFunc[string, any](
			func(ttl *ttlcache.Cache[string, any], _ string) *ttlcache.Item[string, any] {
				var o []relation.ProductOption
				rows, err := db.session.SelectBySql("SELECT "+
					strings.Join(productOptionSelectedSelection(ln), ", ")+
					" FROM `"+key.Table()+"`"+
					" ARRAY JOIN (SELECT `options` from `product_variant` where `id` = ?) as opt"+
					" WHERE id = tupleElement(opt, 1)"+
					" ORDER BY position", key.Args()).
					Load(&o)
				if rows < 1 || err != nil {
					return nil
				}

				return ttl.Set(key.String(), o, key.TTL())
			},
		)
	)

	if p := db.cache.Get(key.String(), ttlcache.WithLoader[string, any](l)); p != nil {
		for _, option := range p.Value().([]relation.ProductOption) {
			options = append(options, option.AsSelected())
		}
	}

	return options, nil
}

func (db *clickhouse) Ping() error {
	return db.session.Ping()
}

func (db *clickhouse) Close() error {
	var wg sync.WaitGroup
	wg.Add(2)

	go func() {
		defer wg.Done()

		if db.cache != nil {
			db.cache.DeleteAll()
			db.cache.Stop()
		}
	}()

	go func() {
		defer wg.Done()

		if db.session != nil {
			_ = db.session.Close()
		}
	}()

	return nil
}