<?php
/**
 * ambre-internal-memory.php · wave-258 · Memoire persistante illimitee pour chats INTERNES
 * Public chats (/wevia, widget /) → session 24h
 * Internal chats (wevia-master, all-ia-hub, orchestrator) → persistent unlimited
 */

class AmbreInternalMemory {
    const DIR = "/opt/wevads/internal-memory";
    const MAX_TURNS = 10000;  // unlimited effectively
    const TTL_HOURS = 0;  // 0 = no expiry
    
    public static function init() {
        if (!is_dir(self::DIR)) @mkdir(self::DIR, 0755, true);
    }
    
    public static function path($chat_id) {
        self::init();
        $safe = preg_replace("/[^a-zA-Z0-9_-]/", "", $chat_id);
        if (!$safe) $safe = "default";
        return self::DIR . "/" . $safe . ".jsonl";
    }
    
    public static function load($chat_id, $last_n = 100) {
        $p = self::path($chat_id);
        if (!file_exists($p)) return [];
        $lines = @file($p, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
        if (!$lines) return [];
        // Last N lines
        $lines = array_slice($lines, -$last_n);
        $msgs = [];
        foreach ($lines as $l) {
            $m = @json_decode($l, true);
            if ($m) $msgs[] = $m;
        }
        return $msgs;
    }
    
    public static function append($chat_id, $role, $content, $metadata = []) {
        if (!$chat_id || !$role || !$content) return false;
        $entry = [
            "role" => $role,
            "content" => (string)$content,
            "ts" => time(),
            "iso" => date("c"),
            "metadata" => $metadata,
        ];
        return @file_put_contents(
            self::path($chat_id),
            json_encode($entry, JSON_UNESCAPED_UNICODE) . "\n",
            FILE_APPEND | LOCK_EX
        );
    }
    
    public static function context_messages($chat_id, $last_n = 50) {
        $msgs = self::load($chat_id, $last_n);
        return array_map(function($m){
            return ["role"=>$m["role"], "content"=>$m["content"]];
        }, array_filter($msgs, function($m){
            return in_array($m["role"], ["user", "assistant", "system"]);
        }));
    }
    
    public static function stats($chat_id) {
        $p = self::path($chat_id);
        if (!file_exists($p)) return ["exists"=>false, "turns"=>0, "size"=>0];
        $lines = @file($p, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
        return [
            "exists" => true,
            "turns" => count($lines ?: []),
            "size_bytes" => filesize($p),
            "path" => $p,
            "first" => ($lines && $lines[0]) ? @json_decode($lines[0], true)["iso"] ?? "?" : "?",
            "last" => ($lines && end($lines)) ? @json_decode(end($lines), true)["iso"] ?? "?" : "?",
        ];
    }
    
    public static function list_chats() {
        self::init();
        $out = [];
        foreach (glob(self::DIR . "/*.jsonl") as $f) {
            $bn = basename($f, ".jsonl");
            $lines = @file($f, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
            $out[] = [
                "chat_id" => $bn,
                "turns" => count($lines ?: []),
                "size_kb" => round(filesize($f)/1024, 1),
                "mtime" => date("c", filemtime($f)),
            ];
        }
        return $out;
    }
}

// If called directly via HTTP, act as API
if (php_sapi_name() !== "cli" && basename($_SERVER["SCRIPT_FILENAME"] ?? "") === "ambre-internal-memory.php") {
    header("Content-Type: application/json; charset=utf-8");
    $raw = file_get_contents("php://input");
    $in = json_decode($raw, true) ?: $_GET;
    $action = $in["action"] ?? "stats";
    $chat_id = $in["chat_id"] ?? "";
    
    switch ($action) {
        case "append":
            $result = AmbreInternalMemory::append($chat_id, $in["role"] ?? "user", $in["content"] ?? "", $in["metadata"] ?? []);
            echo json_encode(["ok"=>(bool)$result, "written"=>$result]);
            break;
        case "load":
            echo json_encode(["ok"=>true, "messages"=>AmbreInternalMemory::load($chat_id, intval($in["n"] ?? 100))]);
            break;
        case "context":
            echo json_encode(["ok"=>true, "messages"=>AmbreInternalMemory::context_messages($chat_id, intval($in["n"] ?? 50))]);
            break;
        case "stats":
            echo json_encode(["ok"=>true, "stats"=>AmbreInternalMemory::stats($chat_id)]);
            break;
        case "list":
            echo json_encode(["ok"=>true, "chats"=>AmbreInternalMemory::list_chats()]);
            break;
        default:
            echo json_encode(["error"=>"unknown action. Use: append|load|context|stats|list"]);
    }
}