<?php
// This file is part of
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
class Teacherview {
    private $cmid;
    private $gradeimporterid;
    private $context;
    private $cellstyle = "border:1px solid black; text-align:center";

    public function __construct (int $cmid, int $gradeimporterid) {
        $this->cmid = $cmid;
        $this->gradeimporterid = $gradeimporterid;
        $this->context = context_module::instance($cmid);
    }

    private function get_cmid () {
        return $this->cmid;
    }
    private function get_gradeimporterid () {
        return $this->gradeimporterid;
    }
    private function get_context () {
        return $this->context;
    }
    private function get_cellstyle () {
        return $this->cellstyle;
    }

    public function make_table () {
        global $DB, $CFG;

        // Prepare variables
        $studentlist = $this->get_studentlist();
        $submissions = $this->get_submissions();

        // Create table
        $table = new html_table();
        $table->align = array('center');
        $table->attributes = array('class' => 'generaltable mod_index');

        $submissions = $this->get_submissions();
        if (!$submissions) {
            $this->no_submissions();
            return;
        }
        $table->data[] = $this->get_table_head($submissions);
        foreach ($studentlist as $student) {
            $table->data[] = $this->get_studentsubmissions($student, $submissions);
        }

        return html_writer::table($table);
    }

    private function get_studentlist () {
        // Get students list with userid as key and fullname as value
        $enrolledusers = get_enrolled_users($this->get_context(), 'mod/gradeimporter:view',
                                        0, 'u.id, u.firstname, u.lastname',
                                        'u.firstname, u.lastname'
                                    );
        $studentlist = array();
        foreach ($enrolledusers as $user) {
            $studentlist[$user->id] = array('name' => $user->firstname." ".$user->lastname,
                                            'id' => $user->id);
        }

        return $studentlist;
    }

    private function get_table_head ($submissions) {
        // Creates teacher view table head
        $header = new html_table_row();

        // Add name header to header row
        $header->cells[] = $this->make_cell(get_string('nameCol', 'gradeimporter'), 1);

        foreach ($submissions as $submission) {
            // $subname = editSub($submission->name, $gradeimporterid, $cmid, $submission->id);
            $header->cells[] = $this->make_cell($submission->name, 2);
        }
        return $header;
    }

    private function get_studentsubmissions ($student, $submissions) {
        global $DB;
        // Create new row for the student
        $row = new html_table_row();

        // Set first cell of the row as the students fullname
        $row->cells[] = $this->make_cell($student["name"], 1);

        // Foreach submission checks if student has a feedback for it
        // If they have, fill it with grade + filename (possibly grade+link to full feedback)
        // If they don't have fill it with grade and filename as -
        foreach ($submissions as $submission) {
            $feedback = $DB->get_record('gradeimporter_feedback',
                                        ['submissionid' => $submission->id,
                                            'studentid' => $student['id']]
                                        );
            if ($feedback) {
                $fileurl = $this->feedback_url($feedback);
                $grade = $feedback->grade;
            } else {
                $fileurl = '-';
                $grade = '-';
            }
            $row->cells[] = $this->make_cell($grade, 1);

            $row->cells[] = $this->make_cell($fileurl, 1);
        }
        return $row;
    }

    private function get_submissions () {
        global $CFG, $DB;
        // Get table prefix
        $tp = $CFG->prefix;

        // Build Query
        $sql = "SELECT id, name, type
                FROM {$tp}gradeimporter_submission
                WHERE gradeimporterid ={$this->get_gradeimporterid()}
                ORDER BY type, id";
        // Query DB
        $submissions = $DB->get_records_sql($sql);
        // Return submissions
        return $submissions;
    }

    private function no_submissions () {
        echo "No submissions";
    }

    private function feedback_url ($feedback) {
        $url = moodle_url::make_pluginfile_url($feedback->contextid,
                                            'mod_gradeimporter',
                                            'submissionfiles',
                                            0,
                                            "/",
                                            $feedback->name,
                                            true
                                        );
        return "<a href='{$url}'>$feedback->name</a>";
    }

    private function make_cell ($text, $colspan) {
        $cell = new html_table_cell($text);
        $cell->style = $this->get_cellstyle();
        $cell->colspan = $colspan;
        return $cell;
    }
}