<?php

namespace App\Commands;

use App\Libraries\AssessmentDocxReader;
use CodeIgniter\CLI\BaseCommand;
use CodeIgniter\CLI\CLI;
use Config\Database;
use Throwable;

class ImportAssessmentDocx extends BaseCommand
{
    protected $group = 'Assessments';
    protected $name = 'assessment:import-docx';
    protected $description = 'Import new-student assessment answers from a DOCX file.';
    protected $usage = 'php spark assessment:import-docx <file.docx> --student-id <id> --form-id <id> [--dry-run] [--overwrite] [--complete]';
    protected $arguments = [
        'file' => 'Path to the DOCX containing the seeded questions and their answers.',
    ];
    protected $options = [
        '--student-id' => 'Required database ID of the student.',
        '--form-id' => 'Required assessment form ID.',
        '--dry-run' => 'Parse and validate without changing the database.',
        '--overwrite' => 'Allow replacement of existing non-empty answers.',
        '--complete' => 'Mark the assessment completed; requires all form questions to have answers.',
    ];

    public function run(array $params)
    {
        $path = trim((string) ($params[0] ?? ''));
        $studentId = $this->positiveOption('student-id');
        $formId = $this->positiveOption('form-id');
        $dryRun = CLI::getOption('dry-run') !== null;
        $overwrite = CLI::getOption('overwrite') !== null;
        $complete = CLI::getOption('complete') !== null;

        if ($path === '' || $studentId === null || $formId === null) {
            CLI::error('File, --student-id, and --form-id are required.');
            CLI::write($this->usage);
            return EXIT_ERROR;
        }

        try {
            $realPath = realpath($path);
            if ($realPath === false) {
                throw new \RuntimeException("DOCX file does not exist: {$path}");
            }

            $db = Database::connect();
            $this->assertTables($db);

            $student = $db->table('students')->select('id, school_id, firstname, lastname')->where('id', $studentId)->get()->getRowArray();
            if ($student === null) {
                throw new \RuntimeException("Student {$studentId} was not found.");
            }

            $form = $db->table('assessment_forms f')
                ->select('f.id, f.name, f.pool_id, f.status, f.school_year, p.name AS pool_name')
                ->join('question_pools p', 'p.id = f.pool_id')
                ->where('f.id', $formId)->get()->getRowArray();
            if ($form === null) {
                throw new \RuntimeException("Assessment form {$formId} was not found.");
            }
            if ((string) $form['pool_name'] !== 'New Student Assessment') {
                throw new \RuntimeException('The selected form does not belong to the New Student Assessment pool.');
            }

            $questions = $db->table('assessment_form_questions fq')
                ->select('q.id, q.text, fq.order_index')
                ->join('assessment_questions q', 'q.id = fq.question_id')
                ->where('fq.form_id', $formId)
                ->orderBy('fq.order_index', 'ASC')->get()->getResultArray();
            if ($questions === []) {
                throw new \RuntimeException('The selected assessment form has no questions.');
            }

            $parsed = (new AssessmentDocxReader())->read($realPath, $questions);
            CLI::write(sprintf(
                'Student: #%d %s %s (%s)',
                $studentId,
                (string) $student['firstname'],
                (string) $student['lastname'],
                (string) ($student['school_id'] ?? 'no school ID')
            ));
            CLI::write(sprintf('Form: #%d %s [%s]', $formId, (string) $form['name'], (string) ($form['school_year'] ?? '')));
            CLI::write(sprintf('Parsed %d document blocks; matched %d of %d questions.', $parsed['block_count'], count($parsed['answers']), count($questions)));
            foreach ($questions as $question) {
                $questionId = (int) $question['id'];
                $length = mb_strlen($parsed['answers'][$questionId] ?? '');
                CLI::write(sprintf('  [%s] question_id=%d answer_chars=%d', $length > 0 ? 'matched' : 'missing', $questionId, $length));
            }

            if ($parsed['answers'] === []) {
                throw new \RuntimeException('No answers were matched. Check that the DOCX contains the exact seeded question text.');
            }
            if ($complete && $parsed['missing'] !== []) {
                throw new \RuntimeException('--complete cannot be used while one or more form questions are missing answers.');
            }

            $assessment = $db->table('student_assessments')->where(['student_id' => $studentId, 'form_id' => $formId])->get()->getRowArray();
            $existingAnswers = [];
            if ($assessment !== null) {
                foreach ($db->table('student_answers')->where('student_assessment_id', (int) $assessment['id'])->get()->getResultArray() as $row) {
                    $existingAnswers[(int) $row['question_id']] = $row;
                }
            }

            $conflicts = [];
            foreach ($parsed['answers'] as $questionId => $answer) {
                $old = trim((string) ($existingAnswers[$questionId]['answer_value'] ?? ''));
                if ($old !== '' && $old !== $answer) {
                    $conflicts[] = $questionId;
                }
            }
            if ($conflicts !== [] && $dryRun) {
                CLI::write('Dry run found ' . count($conflicts) . ' existing answer(s) that differ; an actual import will require --overwrite.', 'yellow');
            } elseif ($conflicts !== [] && ! $overwrite) {
                throw new \RuntimeException('Existing answers differ for question ID(s) ' . implode(', ', $conflicts) . '; rerun with --overwrite after reviewing the dry run.');
            }

            if ($dryRun) {
                CLI::write('Dry run complete; no database rows were changed.', 'yellow');
                return EXIT_SUCCESS;
            }

            $now = date('Y-m-d H:i:s');
            $db->transBegin();
            try {
                if ($assessment === null) {
                    $db->table('student_assessments')->insert([
                        'form_id' => $formId,
                        'student_id' => $studentId,
                        'status' => $complete ? 'completed' : 'in_progress',
                        'assigned_at' => $now,
                        'started_at' => $now,
                        'submitted_at' => $complete ? $now : null,
                        'created_at' => $now,
                        'updated_at' => $now,
                    ]);
                    $assessmentId = (int) $db->insertID();
                } else {
                    $assessmentId = (int) $assessment['id'];
                }

                foreach ($parsed['answers'] as $questionId => $answer) {
                    $payload = ['answer_value' => $answer, 'updated_at' => $now];
                    if (isset($existingAnswers[$questionId])) {
                        if (trim((string) $existingAnswers[$questionId]['answer_value']) !== $answer) {
                            $db->table('student_answers')->where('id', (int) $existingAnswers[$questionId]['id'])->update($payload);
                        }
                    } else {
                        $db->table('student_answers')->insert($payload + [
                            'student_assessment_id' => $assessmentId,
                            'question_id' => $questionId,
                            'created_at' => $now,
                        ]);
                    }
                }

                if ($assessment !== null) {
                    $statusUpdate = ['updated_at' => $now];
                    if ($complete && (string) $assessment['status'] !== 'graded') {
                        $statusUpdate += ['status' => 'completed', 'submitted_at' => $now];
                    } elseif ((string) $assessment['status'] === 'not_started') {
                        $statusUpdate += ['status' => 'in_progress', 'started_at' => $now];
                    }
                    $db->table('student_assessments')->where('id', $assessmentId)->update($statusUpdate);
                }

                if ($db->transStatus() === false) {
                    throw new \RuntimeException('The database rejected one or more imported rows.');
                }
                $db->transCommit();
            } catch (Throwable $e) {
                $db->transRollback();
                throw $e;
            }

            CLI::write(sprintf('Imported %d answer(s) into student assessment #%d.', count($parsed['answers']), $assessmentId), 'green');
            if ($parsed['missing'] !== []) {
                CLI::write(count($parsed['missing']) . ' unanswered question(s) were left unchanged.', 'yellow');
            }
            return EXIT_SUCCESS;
        } catch (Throwable $e) {
            CLI::error($e->getMessage());
            return EXIT_ERROR;
        }
    }

    private function positiveOption(string $name): ?int
    {
        $rawValue = CLI::getOption($name);

        // CodeIgniter 4.7 does not split --option=value. Support that common
        // spelling as well as its native --option value form.
        if ($rawValue === null || $rawValue === true) {
            $prefix = '--' . $name . '=';
            foreach ($_SERVER['argv'] ?? [] as $argument) {
                if (is_string($argument) && str_starts_with($argument, $prefix)) {
                    $rawValue = substr($argument, strlen($prefix));
                    break;
                }
            }
        }

        $value = filter_var($rawValue, FILTER_VALIDATE_INT, ['options' => ['min_range' => 1]]);
        return $value === false ? null : (int) $value;
    }

    private function assertTables($db): void
    {
        foreach (['students', 'question_pools', 'assessment_questions', 'assessment_forms', 'assessment_form_questions', 'student_assessments', 'student_answers'] as $table) {
            if (! $db->tableExists($table)) {
                throw new \RuntimeException("Required table {$table} does not exist; run the migrations first.");
            }
        }
    }
}