#!/bin/php
<?php

/***********************************************************************************************************************
 * Simple Postman Collection Converter
 *
 * Author: Anthony Axenov (c) 2021
 * Version: v1.0
 * License: MIT
 * Dependecies: php8.0, php-json
 *
 * This script converts Postman Collection v2.1 to http-files:
 * 1) builds same directory tree as in collection
 * 2) builds ready to run *.http files (except you use Postman's environment vars)
 * 3) builds *.md file with description and examples
 *
 * Usage:
 *
 * 1) Export collection from Postman as described here using 'Collection v2.1':
 *    https://learning.postman.com/docs/getting-started/importing-and-exporting-data/#exporting-collections
 *
 * 2) Run:
 *
 *    php convert.php /path/to/collection.json
 *
 * 3) Optional: you can make script executable first and then run as usual:
 *
 *    sudo chmod a+x convert.php
 *    ./convert.php /path/to/collection.json
 *
 * Note: '~' alias is allowed, it will be replaced to current user home dir.
 *
 * Note: this script was quickly written to solve one exact problem in one NDA-project, so it may contain
 * stupid errors and (for sure) doesn't cover ALL of possible cases according to collection scheme. So feel
 * free to fork and change this script according your needs and to propose your fixes here.
 **********************************************************************************************************************/

declare(strict_types = 1);

/**
 * Writes all arguments in stdout in proper human-readable format
 *
 * @param mixed ...$data
 * @return void
 */
function out(mixed ...$data): void
{
    $result = [];
    foreach ($data as $something) {
        is_array($something) && $something = var_export($something, true);
        empty($something) && $something = '';
        if (is_object($something)) {
            if (method_exists($something, 'toArray')) {
                $something = $something->toArray();
            } elseif (method_exists($something, 'jsonSerialize')) {
                $something = $something->jsonSerialize();
            } else {
                $something = var_export($something, true);
            }
        }
        $result[] = $something;
    }
    printf('[' . date('H:i:s') . '] ' . implode(' ', $result) . PHP_EOL);
}

/**
 * Read Postman collection file
 *
 * @param string $path Path to file (`~` allowed)
 * @return object JSON-decoded object
 * @throws Exception
 */
function read_collection_file(string $path): object
{
    $content = file_get_contents(str_replace('~/', $_SERVER['HOME'], $path));
    $json = json_decode($content);
    return json_last_error() === JSON_ERROR_NONE
        ? $json
        : throw new Exception(
            "File '$path' does not contain a valid json. Error: [" . json_last_error() . "] " . json_last_error_msg()
        );
}

/**
 * Writes data from $request as *.http-file into $dir_tree
 *
 * @param object $request Request data
 * @param string|null $dir_tree Directory path
 * @return void
 */
function write_request(object $request, ?string $dir_tree = null)
{
    $filepath = './files/' . ($dir_tree ? $dir_tree . '/' : '') . $request->name;
    $httpfile = "$filepath.http";
    $mdfile = "$filepath.md";

    // name
    //file_put_contents($httpfile, "# $request->name\n\n", FILE_APPEND);
    file_put_contents($mdfile, "# $request->name\n\n", FILE_APPEND);

    // description (if exists)
    isset($request->request->description) && /*file_put_contents(
        $httpfile,
        '# ' . str_replace("\n", "\n# ", $request->request->description) . "\n\n",
        FILE_APPEND
    ) &&*/ file_put_contents($mdfile, "{$request->request->description}\n\n", FILE_APPEND);

    // generating request data
    $url = "{$request->request->method} {$request->request->url->raw} HTTP/1.1";
    $headers = [];
    $body = '';
    if (count($request->request->header) > 0) {
        foreach ($request->request->header as $header) {
            $headers[(empty($header->disabled) ? '' : '# ') . $header->key] = $header->value;
        }
    }
    if (isset($request->request->body)) {
        $bodymode = $request->request->body->mode;
        if (($request->request->body->options->$bodymode->language ?? '') === 'json') {
            empty($headers['Content-Type']) && $headers['Content-Type'] = 'application/json';
            empty($headers['Accept']) && $headers['Accept'] = 'application/json';
        }
        array_walk($headers, fn(&$value, $key) => $value = $key . ': ' . $value);
        switch ($bodymode) {
            case 'formdata':
                foreach ($request->request->body->$bodymode as $data) {
                    if ($data->type === 'file' && !empty($data->src)) {
                        foreach ($data->src as $src) {
                            $body .= (empty($data->disabled) ? '' : '# ') . "$data->key=$src\n";
                        }
                    } else {
                        $body .= (empty($data->disabled) ? '' : '# ') . "$data->key=$data->value\n";
                    }
                }
                break;
            default:
                $body = $request->request->body->$bodymode;
        }
    }
    $headers = trim(implode("\n", $headers));
    $body = trim($body);
    file_put_contents($httpfile, trim("$url\n$headers\n\n$body\n"), FILE_APPEND);
    file_put_contents($mdfile, "```\n" . trim("$url\n$headers\n\n$body") . "\n```", FILE_APPEND);

    // response examples
    if (!empty($request->response)) {
        file_put_contents($mdfile, "\n# Examples\n", FILE_APPEND);
        foreach ($request->response as $response) {
            file_put_contents($mdfile, "## $response->name\n```\n$url\n", FILE_APPEND);
            foreach ($response->header as $header) {
                file_put_contents($mdfile, "$header->key=$header->value\n", FILE_APPEND);
            }
            file_put_contents($mdfile, "\n$body\n```\nResult:\n```\n$response->body\n```\n", FILE_APPEND);
        }
    }

    out('[OK] ' . $httpfile);
}

/**
 * Processes one item in Postman collection
 * If $item is nested directory then function processes it recursively, otherwise writes *.http-file
 *
 * @param $item
 * @return void
 */
function process_item($item = null)
{
    if (empty($item)) {
        return;
    }
    if (is_array($item)) {
        static $dir_tree;
        static $path;
        foreach ($item as $subitem) {
            if (empty($subitem->item)) {
                write_request($subitem, $path);
            } else {
                $dir_tree[] = $subitem->name;
                $path = implode('/', $dir_tree);
                !file_exists('./files/' . $path) && mkdir('./files/' . $path);
                isset($subitem->description) && file_put_contents(
                    './files/' . $path . '/README.md',
                    $subitem->description
                );
                process_item($subitem->item);
                array_pop($dir_tree);
                $path = implode('/', $dir_tree);
            }
        }
    } else {
        write_request($item, '');
    }
}

/**
 * Recursively removes directory
 *
 * @param string $path
 * @return void
 */
function remove_directory(string $path): void
{
    $files = glob($path . '/*');
    foreach ($files as $file) {
        is_dir($file) ? remove_directory($file) : unlink($file);
    }
    rmdir($path);
}

try {
    remove_directory('./files');
    file_exists('./files/') || mkdir('./files/');
    empty($argv[1]) && throw new Exception('ERROR: No collection file provided');
    file_exists($argv[1]) || throw new Exception('ERROR: Provided collection file does not exist');
    $json = read_collection_file($argv[1]);
    process_item($json->item);
} catch (Exception $e) {
    out($e->getMessage());
    return 1;
}