package gateway

import (
	"net/http"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/contract/enums"
)

// This file owns the read-only client metadata surface: GET /api/v1/meta/enums,
// which publishes the authoritative platform/mood/mode tables (Android
// collaboration B4, design/07 §6). Clients (Web, Android, an IM bridge) read the
// tables instead of hardcoding their own id → label mapping, so a source badge or
// a mood label cannot drift per client. The tables themselves live in
// internal/contract/enums; this handler only serves them, so there is one source
// of truth rather than a copy per consumer.

// metaEnums is the GET /api/v1/meta/enums payload. `unknown` carries the
// machine-readable fallback policy (enums.UnknownFallback) so a client reads the
// tables and the rule for an unlisted value from the same response.
type metaEnums struct {
	Platforms []enums.Item `json:"platforms"`
	Moods     []enums.Item `json:"moods"`
	Modes     []enums.Item `json:"modes"`
	Unknown   string       `json:"unknown"`
}

// handleListEnums serves the shared client enum tables. It is a pure projection
// of the Go-side authority (no store, no error path) and contains nothing
// sensitive, so it is gated like GET /api/v1/sessions: any authenticated role may
// read it.
//
// Adding a value to a table is a non-breaking change for existing clients, which
// must display an unlisted value raw (see enums.UnknownFallback) rather than
// dropping it or erroring.
func (s *Server) handleListEnums(w http.ResponseWriter, _ *http.Request) {
	writeJSON(w, http.StatusOK, metaEnums{
		Platforms: enums.Platforms(),
		Moods:     enums.Moods(),
		Modes:     enums.Modes(),
		Unknown:   enums.UnknownFallback,
	})
}