<?php
// Storage in bulk, the way any app calls it (storage's README, "For an app: in bulk"): a JSON call
// to storage with rc_app_headers("storage", true), and the bytes straight to B2 and back on the
// presigned URLs it hands out. No storage key, and no byte passes through storage's PHP.
//
//     [$s, $r] = storage_call("begin", ["files" => [["path" => "postcards/a.png", "size" => 812, "type" => "image/png"]]]);
//     // $r["files"][0]: {id, url, type, size, expires}; PUT the bytes to url with that Content-Type
//     storage_call("commit", ["ids" => [$id, ...]]);       // one B2 listing for the whole begin
//     storage_call("urls", ["ids" => [$id, ...]]);         // presigned GETs, five minutes each
//     storage_call("list", ["after" => 0, "limit" => 1000]);   // what the zoo saved for this person

function storage_call(string $op, array $in = []): array {
    [$s, $out] = call_app("storage", "/app/$op", true, "POST", json_encode($in), ["Content-Type: application/json"], 55);
    $j = json_decode($out, true);
    return [$s, is_array($j) ? $j : ["error" => "storage answered $s: " . substr($out, 0, 160)]];
}

// PUT many bodies to their presigned URLs, 16 at a time: [status, ...] in order.
// $jobs: [[url, bytes, content type], ...]
function put_many(array $jobs): array {
    return many(array_map(function ($j) {
        $c = curl_init($j[0]);
        curl_setopt_array($c, [CURLOPT_CUSTOMREQUEST => "PUT", CURLOPT_POSTFIELDS => $j[1], CURLOPT_RETURNTRANSFER => true, CURLOPT_TIMEOUT => 30,
            CURLOPT_HTTPHEADER => ["Content-Type: $j[2]", "Expect:"]]);
        return $c;
    }, $jobs));
}

// GET many presigned URLs: [[status, body], ...] in order.
function get_many(array $urls): array {
    return many(array_map(function ($u) {
        $c = curl_init($u);
        curl_setopt_array($c, [CURLOPT_RETURNTRANSFER => true, CURLOPT_TIMEOUT => 30]);
        return $c;
    }, $urls), true);
}

function many(array $handles, bool $bodies = false): array {
    $mh = curl_multi_init();
    $out = [];
    foreach (array_chunk($handles, 16, true) as $chunk) {
        foreach ($chunk as $c) curl_multi_add_handle($mh, $c);
        do { curl_multi_exec($mh, $running); curl_multi_select($mh, 0.2); } while ($running);
        foreach ($chunk as $i => $c) {
            $code = (int)curl_getinfo($c, CURLINFO_HTTP_CODE);
            $out[$i] = $bodies ? [$code, (string)curl_multi_getcontent($c)] : $code;
            curl_multi_remove_handle($mh, $c);
        }
    }
    return $out;
}