package storage

import (
	"context"
	"errors"
	"fmt"
	"local/dndex/config"
	"local/dndex/storage/driver"
	"local/dndex/storage/entity"
	"local/dndex/storage/operator"
	"strings"

	"go.mongodb.org/mongo-driver/bson"
)

type Graph struct {
	driver driver.Driver
}

func NewGraph() Graph {
	var d driver.Driver
	switch strings.ToLower(config.New().DriverType) {
	case "mongo":
		d = driver.NewMongo()
	case "boltdb":
		d = driver.NewBoltDB()
	}
	return Graph{
		driver: d,
	}
}

func (g Graph) Search(ctx context.Context, namespace string, nameContains string) ([]entity.One, error) {
	filter := operator.Regex{Key: entity.Name, Value: fmt.Sprintf(".*%s.*", nameContains)}
	return g.find(ctx, namespace, filter)
}

func (g Graph) ListCaseInsensitive(ctx context.Context, namespace string, from ...string) ([]entity.One, error) {
	if len(from) == 0 {
		return g.List(ctx, namespace)
	}
	pattern := strings.Join(from, "|")
	pattern = "^(?i)(" + pattern + ")"
	filter := operator.Regex{Key: entity.Name, Value: pattern}
	return g.find(ctx, namespace, filter)
}

func (g Graph) List(ctx context.Context, namespace string, from ...string) ([]entity.One, error) {
	filter := operator.NewFilterIn(entity.Name, from)
	return g.find(ctx, namespace, filter)
}

func (g Graph) find(ctx context.Context, namespace string, filter interface{}) ([]entity.One, error) {
	ch, err := g.driver.Find(ctx, namespace, filter)
	if err != nil {
		return nil, err
	}
	return g.gatherOnes(ctx, ch)
}

func (g Graph) gatherOnes(ctx context.Context, ch <-chan bson.Raw) ([]entity.One, error) {
	var ones []entity.One
	for one := range ch {
		var o entity.One
		if err := bson.Unmarshal(one, &o); err != nil {
			return nil, err
		}
		ones = append(ones, o)
	}
	return ones, nil
}

func (g Graph) Insert(ctx context.Context, namespace string, one entity.One) error {
	if ones, err := g.ListCaseInsensitive(ctx, namespace, one.Name); err != nil {
		return err
	} else if len(ones) > 0 {
		return errors.New("collision on primary key when case insensitive")
	}
	return g.driver.Insert(ctx, namespace, one)
}

func (g Graph) Update(ctx context.Context, namespace string, one entity.One, modify interface{}) error {
	return g.driver.Update(ctx, namespace, one, modify)
}

func (g Graph) Delete(ctx context.Context, namespace string, filter interface{}) error {
	return g.driver.Delete(ctx, namespace, filter)
}