#!/usr/bin/env php
<?php

declare(strict_types=1);

/**
 * run.php — Arboricx PHP host shell via libarboricx C ABI.
 *
 * Usage:
 *   php run.php run <bundle.arboricx> [args...]
 *   php run.php inspect <bundle.arboricx>
 */

require __DIR__ . '/src/ffi.php';

use function Arboricx\{ctx_init, ctx_free, loadBundleDefault, ofNumber, ofString, app, reduce, toString, toBool, toNumber};

// ── Locate libarboricx.so ──────────────────────────────────────────────────

function findLib(): string
{
    $env = getenv('ARBORICX_LIB');
    if ($env !== false && file_exists($env)) {
        return $env;
    }

    $paths = [
        __DIR__ . '/../../zig/zig-out/lib/libarboricx.so',
        '/usr/local/lib/libarboricx.so',
        '/usr/lib/libarboricx.so',
        './libarboricx.so',
    ];
    foreach ($paths as $p) {
        if (file_exists($p)) {
            return $p;
        }
    }

    fwrite(STDERR, "Error: libarboricx.so not found.\nSet ARBORICX_LIB to its full path.\n");
    exit(1);
}

// ── Decode helpers ─────────────────────────────────────────────────────────

function decode(\FFI\CData $ctx, int $root): string
{
    // Bool first: false is Leaf, which is also a valid empty string/list.
    try {
        return toBool($ctx, $root) ? 'true' : 'false';
    } catch (\Throwable $e) {
        try {
            return toString($ctx, $root);
        } catch (\Throwable $e2) {
            try {
                return (string) toNumber($ctx, $root);
            } catch (\Throwable $e3) {
                throw new \RuntimeException('could not decode result');
            }
        }
    }
}

function decodeType(\FFI\CData $ctx, int $root): string
{
    try {
        toBool($ctx, $root);
        return 'bool';
    } catch (\Throwable $e) {
        try {
            toString($ctx, $root);
            return 'string';
        } catch (\Throwable $e2) {
            try {
                toNumber($ctx, $root);
                return 'number';
            } catch (\Throwable $e3) {
                return 'unknown (raw tree)';
            }
        }
    }
}

// ── Commands ─────────────────────────────────────────────────────────────────

function readBundle(string $path): string
{
    if (!file_exists($path)) {
        fwrite(STDERR, "Error: bundle not found: $path\n");
        exit(1);
    }
    $bytes = file_get_contents($path);
    if ($bytes === false) {
        fwrite(STDERR, "Error: could not read bundle: $path\n");
        exit(1);
    }
    return $bytes;
}

function cmdRun(string $libPath, string $bundlePath, array $args): void
{
    $ctx = ctx_init($libPath);
    try {
        $term = loadBundleDefault($ctx, readBundle($bundlePath));

        foreach ($args as $arg) {
            $argTree = preg_match('/^\d+$/', $arg) ? ofNumber($ctx, (int)$arg) : ofString($ctx, $arg);
            $term = app($ctx, $term, $argTree);
        }

        $result = reduce($ctx, $term, 1_000_000_000);
        echo decode($ctx, $result) . "\n";
    } finally {
        ctx_free($ctx);
    }
}

function cmdInspect(string $libPath, string $bundlePath): void
{
    $ctx = ctx_init($libPath);
    try {
        $bundle = readBundle($bundlePath);
        echo "Bundle: $bundlePath\nSize: " . strlen($bundle) . " bytes\n\nResult:\n";

        $term = loadBundleDefault($ctx, $bundle);
        $result = reduce($ctx, $term, 1_000_000_000);

        $type = decodeType($ctx, $result);
        try {
            $value = decode($ctx, $result);
        } catch (\RuntimeException $e) {
            $value = '(raw tree)';
        }
        echo "  Type: $type\n  Value: $value\n";
    } finally {
        ctx_free($ctx);
    }
}

// ── Main ─────────────────────────────────────────────────────────────────────

$argv = $_SERVER['argv'] ?? [];
$argc = $_SERVER['argc'] ?? 0;

if ($argc < 2) {
    echo "Arboricx PHP Host Shell (via libarboricx C ABI)\n\nUsage:\n";
    echo "  php run.php run <bundle.arboricx> [args...]\n";
    echo "  php run.php inspect <bundle.arboricx>\n";
    exit(0);
}

$libPath = findLib();
$command = $argv[1];

switch ($command) {
    case 'run':
        if ($argc < 3) {
            fwrite(STDERR, "Usage: php run.php run <bundle.arboricx> [args...]\n");
            exit(1);
        }
        cmdRun($libPath, $argv[2], array_slice($argv, 3));
        break;
    case 'inspect':
        if ($argc < 3) {
            fwrite(STDERR, "Usage: php run.php inspect <bundle.arboricx>\n");
            exit(1);
        }
        cmdInspect($libPath, $argv[2]);
        break;
    default:
        fwrite(STDERR, "Unknown command: $command\nUsage: php run.php run|inspect ...\n");
        exit(1);
}