<?php

require_once "PicturedTask.php";

class VerilogTask extends PicturedTask
{
    private string $test_bench_fn; // test bench file name
    private string $explanation; // short explanation for the marking
    private const FAILED_MARK = "[FAILED]"; // mark at the beginning of testbench results indicating a failed combination

    public function __construct(array &$a = null)
    {
        parent::__construct("verilog", $a);

        $this->explanation = $a["explanation"] ?? "";
        $this->test_bench_fn = $a["test_bench_fn"] ?? "";
    }

    private function verifyCode(): bool
    {
        // check that no $function calls are in the code
        if (str_contains($this->player_answer, "$")) {
            $this->explanation .= "A kód nem tartalmazhat \$függvényhívásokat!\n";
            return false;
        }
        return true;
    }

    private function executeTest(): bool
    {
        // store the user's answer
        $module_code_fn = tempnam(sys_get_temp_dir(), "verilogtask_user_module_");
        file_put_contents($module_code_fn, $this->getPlayerAnswer());

        // modify the test bench and save into a separate file
        $test_bench_fn = tempnam(sys_get_temp_dir(), "verilogtask_test_bench_");
        $include_line = "`include \"$module_code_fn\"\n\n";
        $tb = $include_line . file_get_contents($this->getGameDir() . DIRECTORY_SEPARATOR . $this->test_bench_fn);
        file_put_contents($test_bench_fn, $tb);

        // run the simulation
        $output_fn = sys_get_temp_dir() . DIRECTORY_SEPARATOR . uniqid("verilogtask_output_");
        $iverilog_cmd = "iverilog $test_bench_fn -o $output_fn 2>&1";
        $compilation_log = shell_exec($iverilog_cmd);
        $failed_count = 0;
        if (!is_null($compilation_log)) {
            $compilation_log = str_replace([$module_code_fn, $test_bench_fn], ["[kód]", "[tesztkörnyezet]"], $compilation_log);
            $this->explanation .= "Fordítási hiba:\n\n" . (string)($compilation_log);
            $failed_count = PHP_INT_MAX;
            goto cleanup;
        }

        if (file_exists($output_fn)) {
            $tb_output = shell_exec("$output_fn");
            $tb_output_lines = array_map(fn($line) => trim($line), explode("\n", $tb_output));
            $failed_trimlen = strlen(self::FAILED_MARK);
            foreach ($tb_output_lines as $line) {
                if (str_starts_with($line, self::FAILED_MARK)) {
                    $this->explanation .= substr($line, $failed_trimlen) . "\n";
                    $failed_count++;
                }
            }

            if ($failed_count == 0) {
                $this->explanation .= "Minden rendben! :)";
            } else {
                $this->explanation = "$failed_count db hiba:\n\n" . $this->explanation;
            }
        }

        cleanup:
        // remove the temporary files
        @unlink($module_code_fn);
        @unlink($test_bench_fn);
        @unlink($output_fn);

        return $failed_count == 0;
    }

    public function staticCheck(): void
    {
        $this->explanation = "";

        // verify code
        $mark = 0.0;
        if ($this->verifyCode()) {
            // run the simulation
            $test_ok = $this->executeTest();

            $mark = $test_ok ? 1.0 : 0.0;  // FIXME
        }
        $this->setMark($mark);
    }

    public function toArray(string $mode = "all"): array
    {
        $a = parent::toArray($mode);

        $a["explanation"] = $this->explanation;

        if ($mode == "all") {
            $a["test_bench_fn"] = $this->test_bench_fn;
        }

        return $a;
    }
}