// svxdr — live-data daemon for SvxPortal (nodelist + proxy + astmeta + xlink)
// Copyright (C) 2026 SA7AUX (Björn)
// SPDX-License-Identifier: AGPL-3.0-or-later
//
// This program is free software: you can redistribute it and/or modify it under
// the terms of the GNU Affero General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option) any
// later version. See the LICENSE file for details.

// Package statusnorm holds the ONE rule that turns a reflector's shared sat-login
// (e.g. KT4ROY-ASL, used by all its TG nodes) into the per-TG display callsign
// (KT4ROY-ASL1..4). It is applied ONCE where a status is ingested (the proxy's
// cache fill, and the federation crawl), so every consumer downstream reads
// already-correct data — no per-view special-casing anywhere.
package statusnorm

import "encoding/json"

// Normalize rewrites the callsign of every node in trunks[].nodes and
// satellites[].nodes: rename(callsign, tg) returns the replacement, or "" to keep
// it. All other data is preserved. Parse failure or no change -> raw unchanged.
func Normalize(raw []byte, rename func(callsign string, tg int) string) []byte {
	var top map[string]json.RawMessage
	if json.Unmarshal(raw, &top) != nil {
		return raw
	}
	changed := false

	// Top-level nodes[]: a group can present as a plain node (e.g. a DMR gateway),
	// not only under a trunk/satellite. Keyed by the node's login/identity, so rename
	// by that KEY (its callsign field may be the operator, not the login).
	if blk, ok := top["nodes"]; ok {
		var nm map[string]json.RawMessage
		if json.Unmarshal(blk, &nm) == nil {
			blkChanged := false
			for id, nRaw := range nm {
				var n map[string]json.RawMessage
				if json.Unmarshal(nRaw, &n) != nil {
					continue
				}
				cs, tg := callsignTG(n)
				repl := rename(id, tg) // match on the node's KEY (its login)
				if repl == "" || repl == cs {
					continue
				}
				b, _ := json.Marshal(repl)
				n["callsign"] = b
				if enc, err := json.Marshal(n); err == nil {
					nm[id] = enc
					blkChanged = true
				}
			}
			if blkChanged {
				if enc, err := json.Marshal(nm); err == nil {
					top["nodes"] = enc
					changed = true
				}
			}
		}
	}

	for _, key := range []string{"trunks", "satellites"} {
		blk, ok := top[key]
		if !ok {
			continue
		}
		var group map[string]json.RawMessage
		if json.Unmarshal(blk, &group) != nil {
			continue
		}
		blkChanged := false
		for id, objRaw := range group {
			var obj map[string]json.RawMessage
			if json.Unmarshal(objRaw, &obj) != nil {
				continue
			}
			nodesRaw, ok := obj["nodes"]
			if !ok {
				continue
			}
			var nodes []json.RawMessage
			if json.Unmarshal(nodesRaw, &nodes) != nil {
				continue
			}
			nodesChanged := false
			for i, nRaw := range nodes {
				var n map[string]json.RawMessage
				if json.Unmarshal(nRaw, &n) != nil {
					continue
				}
				cs, tg := callsignTG(n)
				if cs == "" {
					continue
				}
				repl := rename(cs, tg)
				if repl == "" || repl == cs {
					continue
				}
				b, _ := json.Marshal(repl)
				n["callsign"] = b
				if enc, err := json.Marshal(n); err == nil {
					nodes[i] = enc
					nodesChanged = true
				}
			}
			if nodesChanged {
				if enc, err := json.Marshal(nodes); err == nil {
					obj["nodes"] = enc
					if oenc, err := json.Marshal(obj); err == nil {
						group[id] = oenc
						blkChanged = true
					}
				}
			}
		}
		if blkChanged {
			if enc, err := json.Marshal(group); err == nil {
				top[key] = enc
				changed = true
			}
		}
	}
	if !changed {
		return raw
	}
	if enc, err := json.Marshal(top); err == nil {
		return enc
	}
	return raw
}

func callsignTG(n map[string]json.RawMessage) (string, int) {
	var cs string
	if v, ok := n["callsign"]; ok {
		_ = json.Unmarshal(v, &cs)
	}
	var tg int
	if v, ok := n["tg"]; ok {
		_ = json.Unmarshal(v, &tg)
	}
	return cs, tg
}