package adminapi

import (
	"encoding/json"
	"io"
	"net/http"

	"gitea.mynodes.xyz/ilker/llmgw/internal/control/catalog"
)

// CanaryPercentRequest changes the share of a model's requests its canary
// takes.
type CanaryPercentRequest struct {
	Percent int `json:"percent"`
}

func (a *API) registerCanary(mux Mux) {
	need := func(w http.ResponseWriter) bool {
		if a.serve == nil {
			writeError(w, http.StatusNotImplemented, "a canary needs a mirror and a store, and this control plane lacks one")
			return false
		}
		return true
	}
	mux.HandleFunc("GET /api/v1/canaries", func(w http.ResponseWriter, r *http.Request) {
		if !need(w) {
			return
		}
		writeJSON(w, http.StatusOK, a.serve.Canaries())
	})
	// Start one: the newer weights fetched and run beside, then given
	// their share.
	mux.HandleFunc("POST /api/v1/models/{name}/canary", func(w http.ResponseWriter, r *http.Request) {
		if !need(w) {
			return
		}
		var cn catalog.Canary
		if err := json.NewDecoder(io.LimitReader(r.Body, 1<<12)).Decode(&cn); err != nil {
			writeError(w, http.StatusBadRequest, "the request is not valid JSON: "+err.Error())
			return
		}
		job, err := a.serve.StartCanary(r.PathValue("name"), cn, actorOf(r))
		if err != nil {
			writeError(w, http.StatusBadRequest, err.Error())
			return
		}
		writeJSON(w, http.StatusAccepted, job)
	})
	// Change its share.
	mux.HandleFunc("PUT /api/v1/models/{name}/canary", func(w http.ResponseWriter, r *http.Request) {
		if !need(w) {
			return
		}
		var req CanaryPercentRequest
		if err := json.NewDecoder(io.LimitReader(r.Body, 1<<12)).Decode(&req); err != nil {
			writeError(w, http.StatusBadRequest, "the request is not valid JSON: "+err.Error())
			return
		}
		msg, err := a.serve.SetCanaryPercent(r.Context(), r.PathValue("name"), req.Percent, actorOf(r))
		if err != nil {
			writeError(w, http.StatusBadRequest, err.Error())
			return
		}
		writeJSON(w, http.StatusOK, Result{Result: msg})
	})
	mux.HandleFunc("DELETE /api/v1/models/{name}/canary", func(w http.ResponseWriter, r *http.Request) {
		if !need(w) {
			return
		}
		msg, err := a.serve.AbortCanary(r.Context(), r.PathValue("name"), actorOf(r))
		if err != nil {
			writeError(w, http.StatusBadRequest, err.Error())
			return
		}
		writeJSON(w, http.StatusOK, Result{Result: msg})
	})
	mux.HandleFunc("POST /api/v1/models/{name}/promote", func(w http.ResponseWriter, r *http.Request) {
		if !need(w) {
			return
		}
		ch, ok := readChange(w, r)
		if !ok {
			return
		}
		job, err := a.serve.StartPromote(r.PathValue("name"), actorOf(r), ch)
		if err != nil {
			writeError(w, http.StatusBadRequest, err.Error())
			return
		}
		writeJSON(w, http.StatusAccepted, job)
	})
}