// Package social owns friendships, private conversations and the persistent inbox.
package social

import (
	"context"
	"strings"
	"unicode/utf8"

	"github.com/google/uuid"
	"github.com/jackc/pgx/v5/pgxpool"
	"pipu/api/internal/api/gen"
	"pipu/api/internal/auth"
	"pipu/api/internal/platform/apperr"
)

type ActivityPlaylistReader interface {
	ReadSocialPlaylist(context.Context, uuid.UUID) (gen.Playlist, error)
}

type Handler struct {
	store     *Store
	playlists ActivityPlaylistReader
}

func NewHandler(pool *pgxpool.Pool, playlists ActivityPlaylistReader) *Handler {
	return &Handler{store: &Store{pool: pool}, playlists: playlists}
}
func userID(ctx context.Context) (uuid.UUID, error) {
	p, ok := auth.PrincipalFrom(ctx)
	if !ok {
		return uuid.Nil, apperr.Unauthorized("auth.unauthorized", "sign in required")
	}
	return p.UserID, nil
}
func invalid() error {
	return apperr.Validation("social", "social.invalid", "invalid social operation", nil)
}
func denied() error {
	return apperr.Forbidden("social.unavailable", "friendship required or person unavailable")
}

func (h *Handler) GetSocial(ctx context.Context, _ gen.GetSocialRequestObject) (gen.GetSocialResponseObject, error) {
	id, e := userID(ctx)
	if e != nil {
		return nil, e
	}
	v, e := h.store.inbox(ctx, id)
	return gen.GetSocial200JSONResponse(v), e
}
func (h *Handler) SearchPeople(ctx context.Context, r gen.SearchPeopleRequestObject) (gen.SearchPeopleResponseObject, error) {
	id, e := userID(ctx)
	if e != nil {
		return nil, e
	}
	q := strings.TrimSpace(r.Params.Q)
	if utf8.RuneCountInString(q) < 2 || utf8.RuneCountInString(q) > 80 {
		return nil, invalid()
	}
	v, e := h.store.people(ctx, id, q)
	return gen.SearchPeople200JSONResponse(v), e
}
func (h *Handler) SocialAction(ctx context.Context, r gen.SocialActionRequestObject) (gen.SocialActionResponseObject, error) {
	id, e := userID(ctx)
	if e != nil {
		return nil, e
	}
	if r.Body == nil || r.Body.TargetId == uuid.Nil || r.Body.TargetId == id {
		return nil, invalid()
	}
	if e = h.store.action(ctx, id, *r.Body); e != nil {
		return nil, e
	}
	return gen.SocialAction204Response{}, nil
}
func (h *Handler) GetDirectMessages(ctx context.Context, r gen.GetDirectMessagesRequestObject) (gen.GetDirectMessagesResponseObject, error) {
	id, e := userID(ctx)
	if e != nil {
		return nil, e
	}
	if r.PeerId == uuid.Nil || r.PeerId == id || (r.Params.Before != nil && *r.Params.Before < 1) {
		return nil, invalid()
	}
	q := ""
	if r.Params.Q != nil {
		q = strings.TrimSpace(*r.Params.Q)
	}
	if utf8.RuneCountInString(q) > 100 {
		return nil, invalid()
	}
	v, e := h.store.messagePage(ctx, id, r.PeerId, r.Params.Before, q)
	return gen.GetDirectMessages200JSONResponse(v), e
}
func validateMessage(m gen.SendDirectMessage) error {
	if m.ReplyTo != nil && *m.ReplyTo == uuid.Nil {
		return invalid()
	}
	if m.Id == uuid.Nil || utf8.RuneCountInString(m.Text) > 4000 {
		return invalid()
	}
	switch m.AttachmentKind {
	case "none":
		if strings.TrimSpace(m.Text) == "" || m.AttachmentId != nil {
			return invalid()
		}
	case "track", "playlist":
		if m.AttachmentId == nil || *m.AttachmentId == uuid.Nil {
			return invalid()
		}
	default:
		return invalid()
	}
	return nil
}
func (h *Handler) SendDirectMessage(ctx context.Context, r gen.SendDirectMessageRequestObject) (gen.SendDirectMessageResponseObject, error) {
	id, e := userID(ctx)
	if e != nil {
		return nil, e
	}
	if r.Body == nil || r.PeerId == id || r.PeerId == uuid.Nil {
		return nil, invalid()
	}
	if e = validateMessage(*r.Body); e != nil {
		return nil, e
	}
	v, e := h.store.send(ctx, id, r.PeerId, *r.Body)
	return gen.SendDirectMessage200JSONResponse(v), e
}