<?php

	use Reflect\Call;
	use Reflect\{Response, Path};

	const ERRNO_CACHE_FAILED = 0;

	const FORGEJO_ENDPOINT_USER = "/api/v1/users/%s";
	const FORGEJO_ENDPOINT_SEARCH = "/api/v1/repos/search?uid=%s";

	class POST_AboutLanguages {
		private array $errors = [];
		// Tally of all languages used in all configured repositories
		private array $languages = [];

		public function __construct() {}

		// Fetch JSON from URL
		private static function fetch_json(string $url): array {
			return json_decode(file_get_contents($url), true);
		}

		// Fetch JSON from a Forgejo endpoint
		private static function fetch_endpoint(string $endpoint): array {
			$url = $_ENV["forgejo"]["base_url"] . $endpoint;
			return self::fetch_json($url);
		}

		// Write $this->languages to a JSON file
		private function cache_languages(): int|bool {
			$cache_filename = $_ENV["forgejo_languages"]["cache_file"];

			// Bail out if cache file is not configured
			if (empty($cache_filename)) {
				return true;
			}

			return file_put_contents($cache_filename, json_encode($this->languages));
		}

		// Fetch and add languages to total from a fully-qualified Forgejo URL
		private function add_repository_languages(string $url): void {
			foreach(self::fetch_json($url) as $language => $bytes) {
				// Create key for language if it doesn't exist
				if (!array_key_exists($language, $this->languages)) {
					$this->languages[$language] = 0;
				}

				// Add bytes to language in total
				$this->languages[$language] += $bytes;
			}
		}

		// Tally languages from public repositories for user id
		private function add_public_repositores(int $uid): bool {
			$resp = self::fetch_endpoint(sprintf(FORGEJO_ENDPOINT_SEARCH, $uid));

			// Bail out if request failed or if response indicated a problem
			if (!$resp or $resp["ok"] === false) {
				return false;
			}

			// Add langauges for each public repository
			foreach ($resp["data"] as $repo) {
				$this->add_repository_languages($repo["languages_url"]);
			}

			return true;
		}

		// Add languages from all public repositories for profiles in config
		private function add_repositories_from_config_profiles(): void {
			foreach(explode(",", $_ENV["forgejo_languages"]["scan_profiles"]) as $profile) {
				// Resolve user data from username
				$user = self::fetch_endpoint(sprintf(FORGEJO_ENDPOINT_USER, $profile));
				
				if (!$this->add_public_repositores($user["id"])) {
					$this->errors[] = $profile;
				}
			}
		}

		public function main(): Response {
			$this->add_repositories_from_config_profiles();

			// Sort langauges bytes tally by largest in descending order
			arsort($this->languages);

			// Save languages to cache
			if (!$this->cache_languages()) {
				$this->errors[] = ERRNO_CACHE_FAILED;
			}

			return new Response($this->languages);
		}
	}