package waymaker

// Collections subsystem — Redis-shape Hash / Set / Queue backed by the
// server's WaymakerCollectionsService RPCs.
//
// All wire conventions (subject patterns, tombstone markers) live
// server-side. This client calls typed RPCs only.
//
// Entry points on *Client:
//   Hash:  CreateHashStore / GetOrCreateHashStore / HashStore(name) / DeleteHashStore
//   Set:   CreateSetStore / GetOrCreateSetStore / SetStore(name) / DeleteSetStore
//   Queue: CreateQueue / GetOrCreateQueue / Queue(name) / DeleteQueue

import (
	"context"

	pb "git.awesomike.com/pub/waymaker-client/go/genpb/collections"
)

// ============================================================
// Hash
// ============================================================

// HashStoreConfig is the Hash store creation config.
type HashStoreConfig struct {
	Name      string
	MaxBytes  *uint64
	Ephemeral bool
}

// HashStore is a reference to a named hash store. Cheap to copy.
type HashStore struct {
	client *Client
	Name   string
}

func newHashStore(c *Client, name string) *HashStore {
	return &HashStore{client: c, Name: name}
}

// Hash returns a handle to the hash identified by hashKey within this store.
func (s *HashStore) Hash(hashKey string) *Hash {
	return &Hash{client: s.client, bucket: s.Name, hashKey: hashKey}
}

// Hash is a per-key hash within a HashStore.
type Hash struct {
	client  *Client
	bucket  string
	hashKey string
}

// Set stores field → value. Returns the revision.
func (h *Hash) Set(ctx context.Context, field string, value []byte) (uint64, error) {
	c := h.client.collectionsClient()
	r, err := c.HashSet(ctx, &pb.HashSetRequest{
		Bucket:  h.bucket,
		HashKey: h.hashKey,
		Field:   field,
		Value:   value,
	})
	if err != nil {
		return 0, rpcErr(err)
	}
	if !r.GetSuccess() {
		return 0, serverErr(r.GetResultCode(), r.GetMessage())
	}
	return r.GetRevision(), nil
}

// Get returns the value for field. Returns (nil, nil) when absent.
func (h *Hash) Get(ctx context.Context, field string) ([]byte, error) {
	c := h.client.collectionsClient()
	r, err := c.HashGet(ctx, &pb.HashGetRequest{
		Bucket:  h.bucket,
		HashKey: h.hashKey,
		Field:   field,
	})
	if err != nil {
		return nil, rpcErr(err)
	}
	if !r.GetSuccess() {
		return nil, serverErr(r.GetResultCode(), r.GetMessage())
	}
	return r.GetValue(), nil
}

// Exists tests whether field exists.
func (h *Hash) Exists(ctx context.Context, field string) (bool, error) {
	c := h.client.collectionsClient()
	r, err := c.HashExists(ctx, &pb.HashExistsRequest{
		Bucket:  h.bucket,
		HashKey: h.hashKey,
		Field:   field,
	})
	if err != nil {
		return false, rpcErr(err)
	}
	if !r.GetSuccess() {
		return false, serverErr(r.GetResultCode(), r.GetMessage())
	}
	return r.GetExists(), nil
}

// DeleteField removes field from the hash.
func (h *Hash) DeleteField(ctx context.Context, field string) error {
	c := h.client.collectionsClient()
	r, err := c.HashDelete(ctx, &pb.HashDeleteRequest{
		Bucket:  h.bucket,
		HashKey: h.hashKey,
		Field:   field,
	})
	if err != nil {
		return rpcErr(err)
	}
	if !r.GetSuccess() {
		return serverErr(r.GetResultCode(), r.GetMessage())
	}
	return nil
}

// Fields returns all field names in the hash.
func (h *Hash) Fields(ctx context.Context) ([]string, error) {
	c := h.client.collectionsClient()
	r, err := c.HashFields(ctx, &pb.HashFieldsRequest{
		Bucket:  h.bucket,
		HashKey: h.hashKey,
	})
	if err != nil {
		return nil, rpcErr(err)
	}
	if !r.GetSuccess() {
		return nil, serverErr(r.GetResultCode(), r.GetMessage())
	}
	return r.GetFields(), nil
}

// Len returns the number of fields in the hash.
func (h *Hash) Len(ctx context.Context) (uint64, error) {
	c := h.client.collectionsClient()
	r, err := c.HashLen(ctx, &pb.HashLenRequest{
		Bucket:  h.bucket,
		HashKey: h.hashKey,
	})
	if err != nil {
		return 0, rpcErr(err)
	}
	if !r.GetSuccess() {
		return 0, serverErr(r.GetResultCode(), r.GetMessage())
	}
	return r.GetCount(), nil
}

// GetAll returns every field → value pair in the hash.
func (h *Hash) GetAll(ctx context.Context) (map[string][]byte, error) {
	c := h.client.collectionsClient()
	r, err := c.HashGetAll(ctx, &pb.HashGetAllRequest{
		Bucket:  h.bucket,
		HashKey: h.hashKey,
	})
	if err != nil {
		return nil, rpcErr(err)
	}
	if !r.GetSuccess() {
		return nil, serverErr(r.GetResultCode(), r.GetMessage())
	}
	out := make(map[string][]byte, len(r.GetEntries()))
	for _, e := range r.GetEntries() {
		out[e.GetField()] = e.GetValue()
	}
	return out, nil
}

// --- Client HashStore entry points ---

// CreateHashStore creates a new hash store.
func (c *Client) CreateHashStore(ctx context.Context, config HashStoreConfig) (*HashStore, error) {
	cc := c.collectionsClient()
	r, err := cc.CreateHashStore(ctx, &pb.CreateHashStoreRequest{
		Name:      config.Name,
		MaxBytes:  uint64OrZero(config.MaxBytes),
		Ephemeral: config.Ephemeral,
	})
	if err != nil {
		return nil, rpcErr(err)
	}
	if !r.GetSuccess() {
		return nil, serverErr(r.GetResultCode(), r.GetMessage())
	}
	return newHashStore(c, config.Name), nil
}

// GetOrCreateHashStore is idempotent.
func (c *Client) GetOrCreateHashStore(ctx context.Context, config HashStoreConfig) (*HashStore, error) {
	s, err := c.CreateHashStore(ctx, config)
	if err == nil {
		return s, nil
	}
	if IsServerCode(err, "already_exists") {
		return newHashStore(c, config.Name), nil
	}
	return nil, err
}

// HashStoreHandle returns a handle without verifying existence.
func (c *Client) HashStoreHandle(name string) *HashStore {
	return newHashStore(c, name)
}

// DeleteHashStore deletes the hash store.
func (c *Client) DeleteHashStore(ctx context.Context, name string) error {
	cc := c.collectionsClient()
	r, err := cc.DeleteHashStore(ctx, &pb.DeleteHashStoreRequest{Name: name})
	if err != nil {
		return rpcErr(err)
	}
	if !r.GetSuccess() {
		return serverErr(r.GetResultCode(), r.GetMessage())
	}
	return nil
}

// ============================================================
// Set
// ============================================================

// SetStoreConfig is the Set store creation config.
type SetStoreConfig struct {
	Name      string
	MaxBytes  *uint64
	Ephemeral bool
}

// SetStore is a reference to a named set store. Cheap to copy.
type SetStore struct {
	client *Client
	Name   string
}

func newSetStore(c *Client, name string) *SetStore {
	return &SetStore{client: c, Name: name}
}

// Set returns a handle to the set identified by setKey.
func (s *SetStore) Set(setKey string) *Set {
	return &Set{client: s.client, bucket: s.Name, setKey: setKey}
}

// Set is a per-key set within a SetStore.
type Set struct {
	client *Client
	bucket string
	setKey string
}

// Add adds member to the set.
func (s *Set) Add(ctx context.Context, member string) error {
	c := s.client.collectionsClient()
	r, err := c.SetAdd(ctx, &pb.SetAddRequest{
		Bucket: s.bucket,
		SetKey: s.setKey,
		Member: member,
	})
	if err != nil {
		return rpcErr(err)
	}
	if !r.GetSuccess() {
		return serverErr(r.GetResultCode(), r.GetMessage())
	}
	return nil
}

// Remove removes member from the set.
func (s *Set) Remove(ctx context.Context, member string) error {
	c := s.client.collectionsClient()
	r, err := c.SetRemove(ctx, &pb.SetRemoveRequest{
		Bucket: s.bucket,
		SetKey: s.setKey,
		Member: member,
	})
	if err != nil {
		return rpcErr(err)
	}
	if !r.GetSuccess() {
		return serverErr(r.GetResultCode(), r.GetMessage())
	}
	return nil
}

// IsMember tests membership.
func (s *Set) IsMember(ctx context.Context, member string) (bool, error) {
	c := s.client.collectionsClient()
	r, err := c.SetIsMember(ctx, &pb.SetIsMemberRequest{
		Bucket: s.bucket,
		SetKey: s.setKey,
		Member: member,
	})
	if err != nil {
		return false, rpcErr(err)
	}
	if !r.GetSuccess() {
		return false, serverErr(r.GetResultCode(), r.GetMessage())
	}
	return r.GetIsMember(), nil
}

// Members returns all members.
func (s *Set) Members(ctx context.Context) ([]string, error) {
	c := s.client.collectionsClient()
	r, err := c.SetMembers(ctx, &pb.SetMembersRequest{
		Bucket: s.bucket,
		SetKey: s.setKey,
	})
	if err != nil {
		return nil, rpcErr(err)
	}
	if !r.GetSuccess() {
		return nil, serverErr(r.GetResultCode(), r.GetMessage())
	}
	return r.GetMembers(), nil
}

// Len returns the number of members.
func (s *Set) Len(ctx context.Context) (uint64, error) {
	c := s.client.collectionsClient()
	r, err := c.SetLen(ctx, &pb.SetLenRequest{
		Bucket: s.bucket,
		SetKey: s.setKey,
	})
	if err != nil {
		return 0, rpcErr(err)
	}
	if !r.GetSuccess() {
		return 0, serverErr(r.GetResultCode(), r.GetMessage())
	}
	return r.GetCount(), nil
}

// --- Client SetStore entry points ---

// CreateSetStore creates a new set store.
func (c *Client) CreateSetStore(ctx context.Context, config SetStoreConfig) (*SetStore, error) {
	cc := c.collectionsClient()
	r, err := cc.CreateSetStore(ctx, &pb.CreateSetStoreRequest{
		Name:      config.Name,
		MaxBytes:  uint64OrZero(config.MaxBytes),
		Ephemeral: config.Ephemeral,
	})
	if err != nil {
		return nil, rpcErr(err)
	}
	if !r.GetSuccess() {
		return nil, serverErr(r.GetResultCode(), r.GetMessage())
	}
	return newSetStore(c, config.Name), nil
}

// GetOrCreateSetStore is idempotent.
func (c *Client) GetOrCreateSetStore(ctx context.Context, config SetStoreConfig) (*SetStore, error) {
	s, err := c.CreateSetStore(ctx, config)
	if err == nil {
		return s, nil
	}
	if IsServerCode(err, "already_exists") {
		return newSetStore(c, config.Name), nil
	}
	return nil, err
}

// SetStoreHandle returns a handle without verifying existence.
func (c *Client) SetStoreHandle(name string) *SetStore {
	return newSetStore(c, name)
}

// DeleteSetStore deletes the set store.
func (c *Client) DeleteSetStore(ctx context.Context, name string) error {
	cc := c.collectionsClient()
	r, err := cc.DeleteSetStore(ctx, &pb.DeleteSetStoreRequest{Name: name})
	if err != nil {
		return rpcErr(err)
	}
	if !r.GetSuccess() {
		return serverErr(r.GetResultCode(), r.GetMessage())
	}
	return nil
}

// ============================================================
// Queue
// ============================================================

// QueueConfig is the Queue creation config.
type QueueConfig struct {
	Name        string
	MaxBytes    *uint64
	MaxMessages *uint64
	Ephemeral   bool
}

// Queue is an RPUSH/LPOP-style append queue.
type Queue struct {
	client *Client
	Name   string
}

func newQueue(c *Client, name string) *Queue {
	return &Queue{client: c, Name: name}
}

// Push appends value to the queue. Returns the assigned sequence number.
func (q *Queue) Push(ctx context.Context, value []byte) (uint64, error) {
	c := q.client.collectionsClient()
	r, err := c.QueuePush(ctx, &pb.QueuePushRequest{
		Bucket: q.Name,
		Value:  value,
	})
	if err != nil {
		return 0, rpcErr(err)
	}
	if !r.GetSuccess() {
		return 0, serverErr(r.GetResultCode(), r.GetMessage())
	}
	return r.GetSequence(), nil
}

// Pop removes and returns the front element. Returns (nil, nil) when empty.
func (q *Queue) Pop(ctx context.Context) ([]byte, error) {
	c := q.client.collectionsClient()
	r, err := c.QueuePop(ctx, &pb.QueuePopRequest{Bucket: q.Name})
	if err != nil {
		return nil, rpcErr(err)
	}
	if !r.GetSuccess() {
		return nil, serverErr(r.GetResultCode(), r.GetMessage())
	}
	return r.GetValue(), nil
}

// Range returns up to limit items starting from fromSequence.
func (q *Queue) Range(ctx context.Context, from, limit uint64) ([][]byte, error) {
	c := q.client.collectionsClient()
	r, err := c.QueueRange(ctx, &pb.QueueRangeRequest{
		Bucket:       q.Name,
		FromSequence: from,
		Limit:        limit,
	})
	if err != nil {
		return nil, rpcErr(err)
	}
	if !r.GetSuccess() {
		return nil, serverErr(r.GetResultCode(), r.GetMessage())
	}
	return r.GetValues(), nil
}

// Len returns the number of queued messages.
func (q *Queue) Len(ctx context.Context) (uint64, error) {
	c := q.client.collectionsClient()
	r, err := c.QueueLen(ctx, &pb.QueueLenRequest{Bucket: q.Name})
	if err != nil {
		return 0, rpcErr(err)
	}
	if !r.GetSuccess() {
		return 0, serverErr(r.GetResultCode(), r.GetMessage())
	}
	return r.GetCount(), nil
}

// --- Client Queue entry points ---

// CreateQueue creates a new queue.
func (c *Client) CreateQueue(ctx context.Context, config QueueConfig) (*Queue, error) {
	cc := c.collectionsClient()
	r, err := cc.CreateQueue(ctx, &pb.CreateQueueRequest{
		Name:        config.Name,
		MaxBytes:    uint64OrZero(config.MaxBytes),
		MaxMessages: uint64OrZero(config.MaxMessages),
		Ephemeral:   config.Ephemeral,
	})
	if err != nil {
		return nil, rpcErr(err)
	}
	if !r.GetSuccess() {
		return nil, serverErr(r.GetResultCode(), r.GetMessage())
	}
	return newQueue(c, config.Name), nil
}

// GetOrCreateQueue is idempotent.
func (c *Client) GetOrCreateQueue(ctx context.Context, config QueueConfig) (*Queue, error) {
	q, err := c.CreateQueue(ctx, config)
	if err == nil {
		return q, nil
	}
	if IsServerCode(err, "already_exists") {
		return newQueue(c, config.Name), nil
	}
	return nil, err
}

// QueueHandle returns a handle without verifying existence.
func (c *Client) QueueHandle(name string) *Queue {
	return newQueue(c, name)
}

// DeleteQueue deletes the queue.
func (c *Client) DeleteQueue(ctx context.Context, name string) error {
	cc := c.collectionsClient()
	r, err := cc.DeleteQueue(ctx, &pb.DeleteQueueRequest{Name: name})
	if err != nil {
		return rpcErr(err)
	}
	if !r.GetSuccess() {
		return serverErr(r.GetResultCode(), r.GetMessage())
	}
	return nil
}