package httpserver

import (
	"net/http"
	"net/url"
	"strconv"
	"strings"

	"git.yuntuo.hk/k2safe/orbit/internal/fault"
	core "git.yuntuo.hk/k2safe/orbit/model"
	"git.yuntuo.hk/k2safe/orbit/platform/auth"
	"git.yuntuo.hk/k2safe/orbit/platform/events"
	platform "git.yuntuo.hk/k2safe/orbit/platform/model"
)

func RegisterEventSubscriptions(server *http.Server, s *events.Service) {
	mux := server.Handler.(*http.ServeMux)
	mux.HandleFunc("POST /v1/subscriptions", wrap(func(r *http.Request, t auth.Token) (any, int, error) {
		if err := noEventQuery(r); err != nil {
			return nil, 0, err
		}
		var in events.CreateInput
		if err := decodeEventBody(r, &in); err != nil {
			return nil, 0, err
		}
		key, err := idempotencyKey(r)
		if err != nil {
			return nil, 0, err
		}
		out, err := s.Create(r.Context(), t, key, in)
		return out, createdStatus(out.Deduplicated), err
	}))
	mux.HandleFunc("GET /v1/subscriptions", wrap(func(r *http.Request, t auth.Token) (any, int, error) {
		queue, in, err := eventQuery(r, true)
		if err != nil {
			return nil, 0, err
		}
		out, err := s.List(r.Context(), t, queue, in)
		return out, 200, err
	}))
	mux.HandleFunc("GET /v1/subscriptions/{id}", wrap(func(r *http.Request, t auth.Token) (any, int, error) {
		if err := noEventQuery(r); err != nil {
			return nil, 0, err
		}
		out, err := s.Get(r.Context(), t, core.ID(r.PathValue("id")))
		return out, 200, err
	}))
	mux.HandleFunc("POST /v1/subscriptions/{command}", wrap(func(r *http.Request, t auth.Token) (any, int, error) {
		id, command, ok := strings.Cut(r.PathValue("command"), ":")
		if !ok || command != "configure" {
			return nil, 0, fault.NotFound
		}
		if err := noEventQuery(r); err != nil {
			return nil, 0, err
		}
		var in events.ControlInput
		if err := decodeEventBody(r, &in); err != nil {
			return nil, 0, err
		}
		key, err := idempotencyKey(r)
		if err != nil {
			return nil, 0, err
		}
		out, err := s.Control(r.Context(), t, core.ID(id), key, in)
		return out, 200, err
	}))
	mux.HandleFunc("GET /v1/subscriptions/{id}/deliveries", wrap(func(r *http.Request, t auth.Token) (any, int, error) {
		_, in, err := eventQuery(r, false)
		if err != nil {
			return nil, 0, err
		}
		out, err := s.Deliveries(r.Context(), t, core.ID(r.PathValue("id")), in)
		return out, 200, err
	}))
	mux.HandleFunc("GET /v1/subscriptions/{id}/deliveries/{delivery}", wrap(func(r *http.Request, t auth.Token) (any, int, error) {
		if err := noEventQuery(r); err != nil {
			return nil, 0, err
		}
		out, err := s.Detail(r.Context(), t, core.ID(r.PathValue("id")), core.ID(r.PathValue("delivery")))
		return out, 200, err
	}))
	mux.HandleFunc("POST /v1/subscriptions/{id}/deliveries/{command}", wrap(func(r *http.Request, t auth.Token) (any, int, error) {
		delivery, command, ok := strings.Cut(r.PathValue("command"), ":")
		if !ok || command != "retry" {
			return nil, 0, fault.NotFound
		}
		if err := noEventQuery(r); err != nil {
			return nil, 0, err
		}
		var in events.RetryInput
		if err := decodeEventBody(r, &in); err != nil {
			return nil, 0, err
		}
		key, err := idempotencyKey(r)
		if err != nil {
			return nil, 0, err
		}
		out, err := s.Retry(r.Context(), t, core.ID(r.PathValue("id")), core.ID(delivery), key, in)
		return out, 200, err
	}))
}
func noEventQuery(r *http.Request) error {
	if r.URL.RawQuery != "" || r.URL.ForceQuery {
		return fault.Invalid("query parameters are not allowed")
	}
	return nil
}
func eventQuery(r *http.Request, subscriptions bool) (core.ID, events.PageInput, error) {
	var in events.PageInput
	q, err := url.ParseQuery(r.URL.RawQuery)
	if err != nil {
		return "", in, fault.Invalid("invalid query encoding")
	}
	for k, v := range q {
		if len(v) != 1 || (k != "limit" && k != "cursor" && !(subscriptions && k == "queue_id") && !(!subscriptions && k == "state")) {
			return "", in, fault.Invalid("invalid subscription query")
		}
	}
	if q.Has("limit") {
		in.Limit, err = strconv.Atoi(q.Get("limit"))
		if err != nil || in.Limit < 1 || strconv.Itoa(in.Limit) != q.Get("limit") {
			return "", in, fault.Invalid("invalid limit")
		}
	}
	in.Cursor = q.Get("cursor")
	in.State = platform.DeliveryState(q.Get("state"))
	return core.ID(q.Get("queue_id")), in, nil
}