package mongoc

import (
	"git.i2edu.net/i2/go-zero/core/stores/cache"
	"git.i2edu.net/i2/go-zero/core/stores/mongo"
	"git.i2edu.net/i2/go-zero/core/syncx"
	"github.com/globalsign/mgo"
)

var (
	// ErrNotFound is an alias of mgo.ErrNotFound.
	ErrNotFound = mgo.ErrNotFound

	// can't use one SharedCalls per conn, because multiple conns may share the same cache key.
	sharedCalls = syncx.NewSharedCalls()
	stats       = cache.NewStat("mongoc")
)

type (
	// QueryOption defines the method to customize a mongo query.
	QueryOption func(query mongo.Query) mongo.Query

	// CachedCollection interface represents a mongo collection with cache.
	CachedCollection interface {
		Count(query interface{}) (int, error)
		DelCache(keys ...string) error
		FindAllNoCache(v, query interface{}, opts ...QueryOption) error
		FindOne(v interface{}, key string, query interface{}) error
		FindOneNoCache(v, query interface{}) error
		FindOneId(v interface{}, key string, id interface{}) error
		FindOneIdNoCache(v, id interface{}) error
		GetCache(key string, v interface{}) error
		Insert(docs ...interface{}) error
		Pipe(pipeline interface{}) mongo.Pipe
		Remove(selector interface{}, keys ...string) error
		RemoveNoCache(selector interface{}) error
		RemoveAll(selector interface{}, keys ...string) (*mgo.ChangeInfo, error)
		RemoveAllNoCache(selector interface{}) (*mgo.ChangeInfo, error)
		RemoveId(id interface{}, keys ...string) error
		RemoveIdNoCache(id interface{}) error
		SetCache(key string, v interface{}) error
		Update(selector, update interface{}, keys ...string) error
		UpdateNoCache(selector, update interface{}) error
		UpdateId(id, update interface{}, keys ...string) error
		UpdateIdNoCache(id, update interface{}) error
		Upsert(selector, update interface{}, keys ...string) (*mgo.ChangeInfo, error)
		UpsertNoCache(selector, update interface{}) (*mgo.ChangeInfo, error)
	}

	cachedCollection struct {
		collection mongo.Collection
		cache      cache.Cache
	}
)

func newCollection(collection mongo.Collection, c cache.Cache) CachedCollection {
	return &cachedCollection{
		collection: collection,
		cache:      c,
	}
}

func (c *cachedCollection) Count(query interface{}) (int, error) {
	return c.collection.Find(query).Count()
}

func (c *cachedCollection) DelCache(keys ...string) error {
	return c.cache.Del(keys...)
}

func (c *cachedCollection) FindAllNoCache(v, query interface{}, opts ...QueryOption) error {
	q := c.collection.Find(query)
	for _, opt := range opts {
		q = opt(q)
	}
	return q.All(v)
}

func (c *cachedCollection) FindOne(v interface{}, key string, query interface{}) error {
	return c.cache.Take(v, key, func(v interface{}) error {
		q := c.collection.Find(query)
		return q.One(v)
	})
}

func (c *cachedCollection) FindOneNoCache(v, query interface{}) error {
	q := c.collection.Find(query)
	return q.One(v)
}

func (c *cachedCollection) FindOneId(v interface{}, key string, id interface{}) error {
	return c.cache.Take(v, key, func(v interface{}) error {
		q := c.collection.FindId(id)
		return q.One(v)
	})
}

func (c *cachedCollection) FindOneIdNoCache(v, id interface{}) error {
	q := c.collection.FindId(id)
	return q.One(v)
}

func (c *cachedCollection) GetCache(key string, v interface{}) error {
	return c.cache.Get(key, v)
}

func (c *cachedCollection) Insert(docs ...interface{}) error {
	return c.collection.Insert(docs...)
}

func (c *cachedCollection) Pipe(pipeline interface{}) mongo.Pipe {
	return c.collection.Pipe(pipeline)
}

func (c *cachedCollection) Remove(selector interface{}, keys ...string) error {
	if err := c.RemoveNoCache(selector); err != nil {
		return err
	}

	return c.DelCache(keys...)
}

func (c *cachedCollection) RemoveNoCache(selector interface{}) error {
	return c.collection.Remove(selector)
}

func (c *cachedCollection) RemoveAll(selector interface{}, keys ...string) (*mgo.ChangeInfo, error) {
	info, err := c.RemoveAllNoCache(selector)
	if err != nil {
		return nil, err
	}

	if err := c.DelCache(keys...); err != nil {
		return nil, err
	}

	return info, nil
}

func (c *cachedCollection) RemoveAllNoCache(selector interface{}) (*mgo.ChangeInfo, error) {
	return c.collection.RemoveAll(selector)
}

func (c *cachedCollection) RemoveId(id interface{}, keys ...string) error {
	if err := c.RemoveIdNoCache(id); err != nil {
		return err
	}

	return c.DelCache(keys...)
}

func (c *cachedCollection) RemoveIdNoCache(id interface{}) error {
	return c.collection.RemoveId(id)
}

func (c *cachedCollection) SetCache(key string, v interface{}) error {
	return c.cache.Set(key, v)
}

func (c *cachedCollection) Update(selector, update interface{}, keys ...string) error {
	if err := c.UpdateNoCache(selector, update); err != nil {
		return err
	}

	return c.DelCache(keys...)
}

func (c *cachedCollection) UpdateNoCache(selector, update interface{}) error {
	return c.collection.Update(selector, update)
}

func (c *cachedCollection) UpdateId(id, update interface{}, keys ...string) error {
	if err := c.UpdateIdNoCache(id, update); err != nil {
		return err
	}

	return c.DelCache(keys...)
}

func (c *cachedCollection) UpdateIdNoCache(id, update interface{}) error {
	return c.collection.UpdateId(id, update)
}

func (c *cachedCollection) Upsert(selector, update interface{}, keys ...string) (*mgo.ChangeInfo, error) {
	info, err := c.UpsertNoCache(selector, update)
	if err != nil {
		return nil, err
	}

	if err := c.DelCache(keys...); err != nil {
		return nil, err
	}

	return info, nil
}

func (c *cachedCollection) UpsertNoCache(selector, update interface{}) (*mgo.ChangeInfo, error) {
	return c.collection.Upsert(selector, update)
}