<?php
define('APP_URL', 'https://domili.borgal.de');

function load_reschedule_data($conn, $meeting_id, $user_id)
{
    $stmt = mysqli_prepare($conn, "
        SELECT p.id, p.meeting_id, p.proposed_by_user_id, p.proposed_date, p.reason, p.created_at,
               u.username as proposer_name
        FROM meeting_reschedule_proposals p
        LEFT JOIN users u ON p.proposed_by_user_id = u.id
        WHERE p.meeting_id = ? AND p.status = 'pending'
        ORDER BY p.created_at DESC
    ");
    mysqli_stmt_bind_param($stmt, "i", $meeting_id);
    mysqli_stmt_execute($stmt);
    $active_proposals = mysqli_fetch_all(mysqli_stmt_get_result($stmt), MYSQLI_ASSOC);
    mysqli_stmt_close($stmt);

    if (empty($active_proposals)) {
        return ['active_proposals' => [], 'user_votes' => [], 'yes_voters' => [], 'no_voters' => []];
    }

    $proposal_ids = array_column($active_proposals, 'id');
    $ids_list = implode(',', array_map('intval', $proposal_ids));

    $vote_stmt = mysqli_prepare($conn, "SELECT proposal_id, user_id, vote FROM meeting_reschedule_votes WHERE proposal_id IN ($ids_list)");
    mysqli_stmt_execute($vote_stmt);
    $votes = mysqli_fetch_all(mysqli_stmt_get_result($vote_stmt), MYSQLI_ASSOC);
    mysqli_stmt_close($vote_stmt);

    $user_ids = array_unique(array_column($votes, 'user_id'));
    $user_names = [];
    if (!empty($user_ids)) {
        $user_ids_list = implode(',', array_map('intval', $user_ids));
        $user_stmt = mysqli_prepare($conn, "SELECT id, username FROM users WHERE id IN ($user_ids_list)");
        mysqli_stmt_execute($user_stmt);
        $users = mysqli_fetch_all(mysqli_stmt_get_result($user_stmt), MYSQLI_ASSOC);
        mysqli_stmt_close($user_stmt);
        foreach ($users as $u) {
            $user_names[$u['id']] = htmlspecialchars($u['username']);
        }
    }

    $user_votes = [];
    $yes_voters = array_fill_keys($proposal_ids, []);
    $no_voters = array_fill_keys($proposal_ids, []);

    foreach ($votes as $v) {
        if ($v['user_id'] == $user_id) {
            $user_votes[$v['proposal_id']] = $v['vote'];
        }
        $username = $user_names[$v['user_id']] ?? 'Unbekannt';
        if ($v['vote'] === 'yes') {
            $yes_voters[$v['proposal_id']][] = $username;
        } elseif ($v['vote'] === 'no') {
            $no_voters[$v['proposal_id']][] = $username;
        }
    }

    foreach ($active_proposals as &$p) {
        $p['yes_votes'] = count($yes_voters[$p['id']] ?? []);
        $p['no_votes'] = count($no_voters[$p['id']] ?? []);
    }

    return compact('active_proposals', 'user_votes', 'yes_voters', 'no_voters');
}

function handle_reschedule_actions($conn, $meeting_id, $user_id)
{
    // Vorschlag einreichen
    if (isset($_POST['propose_reschedule']) && isset($_POST['new_date']) && isset($_POST['reason'])) {
        $new_date = $_POST['new_date'];
        $reason = $_POST['reason'];

        $check = mysqli_prepare($conn, "SELECT id FROM meeting_reschedule_proposals WHERE meeting_id = ? AND proposed_by_user_id = ? AND status = 'pending'");
        mysqli_stmt_bind_param($check, "ii", $meeting_id, $user_id);
        mysqli_stmt_execute($check);
        $exists = mysqli_fetch_assoc(mysqli_stmt_get_result($check));
        mysqli_stmt_close($check);

        if ($exists) {
            $_SESSION['error_message'] = "Du hast bereits einen Verschiebungsvorschlag eingereicht.";
            return;
        }

        $ins = mysqli_prepare($conn, "INSERT INTO meeting_reschedule_proposals (meeting_id, proposed_by_user_id, proposed_date, reason) VALUES (?, ?, ?, ?)");
        mysqli_stmt_bind_param($ins, "iiss", $meeting_id, $user_id, $new_date, $reason);
        mysqli_stmt_execute($ins);
        $proposal_id = mysqli_insert_id($conn);
        mysqli_stmt_close($ins);

        // 🔥 Automatisch "Ja"-Stimme für den Ersteller
        $auto_vote = mysqli_prepare($conn, "INSERT INTO meeting_reschedule_votes (proposal_id, user_id, vote) VALUES (?, ?, 'yes')");
        mysqli_stmt_bind_param($auto_vote, "ii", $proposal_id, $user_id);
        mysqli_stmt_execute($auto_vote);
        mysqli_stmt_close($auto_vote);

        // ✉️ E-Mail bei Vorschlag
        if (file_exists(__DIR__ . '/vendor/autoload.php')) {
            require_once __DIR__ . '/vendor/autoload.php';
            $mail = new \PHPMailer\PHPMailer\PHPMailer(true);
            $mail->CharSet = 'UTF-8';
            $mail->isHTML(false);

            $orig_date = null;
            $orig_stmt = mysqli_prepare($conn, "SELECT meeting_date FROM meetings WHERE id = ?");
            mysqli_stmt_bind_param($orig_stmt, "i", $meeting_id);
            mysqli_stmt_execute($orig_stmt);
            $orig_row = mysqli_fetch_assoc(mysqli_stmt_get_result($orig_stmt));
            mysqli_stmt_close($orig_stmt);
            $orig_str = $orig_row ? date('d.m.Y', strtotime($orig_row['meeting_date'])) : 'einem Termin';

            try {
                $mail->isSMTP();
                $mail->Host       = SMTP_HOST;
                $mail->SMTPAuth   = true;
                $mail->Username   = SMTP_USERNAME;
                $mail->Password   = SMTP_PASSWORD;
                $mail->SMTPSecure = SMTP_ENCRYPTION;
                $mail->Port       = SMTP_PORT;
                $mail->setFrom(MAIL_FROM_ADDRESS, MAIL_FROM_NAME);

                $proposer = $_SESSION['username'] ?? 'Ein Benutzer';
                $new_fmt = date('d.m.Y H:i', strtotime($new_date));
                $subject = "DoMiLi: Neuer Terminvorschlag für den ursprünglichen Termin vom $orig_str";
                $body = "Hallo %s,\n\n%s hat einen neuen Vorschlag zur Verschiebung des Termins eingereicht.\nNeuer vorgeschlagener Termin: %s\nGrund: %s\n\nBitte stimme erneut ab, ob du teilnehmen möchtest.\n\nZur Abstimmung: DoMiLi-APP\n%s\n\nDein DoMiLi-Team";

                $users_stmt = mysqli_query($conn, "SELECT username, email FROM users WHERE email IS NOT NULL AND email != ''");
                while ($u = mysqli_fetch_assoc($users_stmt)) {
                    if (isset($_SESSION['email']) && $u['email'] === $_SESSION['email']) continue;
                    $mail->addAddress($u['email']);
                    $mail->Subject = $subject;
                    $mail->Body = sprintf($body, $u['username'], $proposer, $new_fmt, $reason, APP_URL . '/index.php');
                    $mail->send();
                    $mail->clearAddresses();
                }
                $_SESSION['success_message'] = "Vorschlag eingereicht! Alle Benutzer wurden benachrichtigt.";
            } catch (Exception $e) {
                $_SESSION['error_message'] = "Fehler beim Senden der E-Mails.";
                error_log("PHPMailer Error: " . $mail->ErrorInfo);
            }
        } else {
            $_SESSION['success_message'] = "Vorschlag eingereicht! (E-Mail nicht verfügbar)";
        }
        return;
    }

    // Abstimmen
    if (isset($_POST['vote_proposal']) && isset($_POST['proposal_id'])) {
        $pid = intval($_POST['proposal_id']);
        $vote = $_POST['vote_proposal'];
        if (!in_array($vote, ['yes', 'no', 'maybe'])) return;

        $check = mysqli_prepare($conn, "SELECT id FROM meeting_reschedule_votes WHERE proposal_id = ? AND user_id = ?");
        mysqli_stmt_bind_param($check, "ii", $pid, $user_id);
        mysqli_stmt_execute($check);
        $existing = mysqli_fetch_assoc(mysqli_stmt_get_result($check));
        mysqli_stmt_close($check);

        if ($existing) {
            $upd = mysqli_prepare($conn, "UPDATE meeting_reschedule_votes SET vote = ? WHERE id = ?");
            mysqli_stmt_bind_param($upd, "si", $vote, $existing['id']);
            mysqli_stmt_execute($upd);
            mysqli_stmt_close($upd);
        } else {
            $ins = mysqli_prepare($conn, "INSERT INTO meeting_reschedule_votes (proposal_id, user_id, vote) VALUES (?, ?, ?)");
            mysqli_stmt_bind_param($ins, "iis", $pid, $user_id, $vote);
            mysqli_stmt_execute($ins);
            mysqli_stmt_close($ins);
        }
        return;
    }

    // Löschen (nur Ersteller)
    if (isset($_POST['delete_proposal']) && isset($_POST['proposal_id'])) {
        $pid = intval($_POST['proposal_id']);
        $check = mysqli_prepare($conn, "SELECT proposed_by_user_id FROM meeting_reschedule_proposals WHERE id = ? AND meeting_id = ?");
        mysqli_stmt_bind_param($check, "ii", $pid, $meeting_id);
        mysqli_stmt_execute($check);
        $owner = mysqli_fetch_assoc(mysqli_stmt_get_result($check));
        mysqli_stmt_close($check);
        if ($owner && $owner['proposed_by_user_id'] == $user_id) {
            mysqli_query($conn, "DELETE FROM meeting_reschedule_votes WHERE proposal_id = $pid");
            mysqli_query($conn, "DELETE FROM meeting_reschedule_proposals WHERE id = $pid");
        }
        return;
    }

    // Bearbeiten (nur Ersteller)
    if (isset($_POST['edit_proposal']) && isset($_POST['proposal_id']) && isset($_POST['new_date']) && isset($_POST['reason'])) {
        $pid = intval($_POST['proposal_id']);
        $new_date = $_POST['new_date'];
        $reason = $_POST['reason'];
        $check = mysqli_prepare($conn, "SELECT proposed_by_user_id FROM meeting_reschedule_proposals WHERE id = ? AND meeting_id = ?");
        mysqli_stmt_bind_param($check, "ii", $pid, $meeting_id);
        mysqli_stmt_execute($check);
        $owner = mysqli_fetch_assoc(mysqli_stmt_get_result($check));
        mysqli_stmt_close($check);
        if ($owner && $owner['proposed_by_user_id'] == $user_id) {
            mysqli_query($conn, "DELETE FROM meeting_reschedule_votes WHERE proposal_id = $pid");
            $upd = mysqli_prepare($conn, "UPDATE meeting_reschedule_proposals SET proposed_date = ?, reason = ? WHERE id = ?");
            mysqli_stmt_bind_param($upd, "ssi", $new_date, $reason, $pid);
            mysqli_stmt_execute($upd);
            mysqli_stmt_close($upd);
        }
        return;
    }

    // Admin: Vorschlag annehmen → MEETING AKTUALISIEREN + E-MAIL
    if (isset($_SESSION['role']) && $_SESSION['role'] === 'admin') {
        if (isset($_POST['accept_proposal']) && isset($_POST['proposal_id'])) {
            $proposal_id = intval($_POST['proposal_id']);

            $proposal_stmt = mysqli_prepare($conn, "
                SELECT p.proposed_date, p.reason, p.meeting_id,
                       m.meeting_date AS original_date
                FROM meeting_reschedule_proposals p
                JOIN meetings m ON p.meeting_id = m.id
                WHERE p.id = ?
            ");
            mysqli_stmt_bind_param($proposal_stmt, "i", $proposal_id);
            mysqli_stmt_execute($proposal_stmt);
            $proposal = mysqli_fetch_assoc(mysqli_stmt_get_result($proposal_stmt));
            mysqli_stmt_close($proposal_stmt);

            if ($proposal) {
                $new_date = $proposal['proposed_date'];
                $new_reason = $proposal['reason'];
                $meeting_id = $proposal['meeting_id'];
                $original_date = $proposal['original_date'];

                // Meeting aktualisieren
                $update_meeting = mysqli_prepare($conn, "
                    UPDATE meetings 
                    SET meeting_date = ?
                    WHERE id = ?
                ");
                mysqli_stmt_bind_param($update_meeting, "ssi", $new_date, $new_reason, $meeting_id);
                mysqli_stmt_execute($update_meeting);
                mysqli_stmt_close($update_meeting);

                // Vorschlag akzeptieren
                $accept_stmt = mysqli_prepare($conn, "
                    UPDATE meeting_reschedule_proposals 
                    SET status = 'accepted' 
                    WHERE id = ?
                ");
                mysqli_stmt_bind_param($accept_stmt, "i", $proposal_id);
                mysqli_stmt_execute($accept_stmt);
                mysqli_stmt_close($accept_stmt);

                // Andere ablehnen
                $reject_others = mysqli_prepare($conn, "
                    UPDATE meeting_reschedule_proposals 
                    SET status = 'rejected' 
                    WHERE meeting_id = ? AND id != ?
                ");
                mysqli_stmt_bind_param($reject_others, "ii", $meeting_id, $proposal_id);
                mysqli_stmt_execute($reject_others);
                mysqli_stmt_close($reject_others);

                // ✉️ E-Mail nach Akzeptanz
                if (file_exists(__DIR__ . '/vendor/autoload.php')) {
                    require_once __DIR__ . '/vendor/autoload.php';
                    $mail = new \PHPMailer\PHPMailer\PHPMailer(true);
                    $mail->CharSet = 'UTF-8';
                    $mail->isHTML(false);

                    try {
                        $mail->isSMTP();
                        $mail->Host       = SMTP_HOST;
                        $mail->SMTPAuth   = true;
                        $mail->Username   = SMTP_USERNAME;
                        $mail->Password   = SMTP_PASSWORD;
                        $mail->SMTPSecure = SMTP_ENCRYPTION;
                        $mail->Port       = SMTP_PORT;
                        $mail->setFrom(MAIL_FROM_ADDRESS, MAIL_FROM_NAME);

                        $orig_fmt = date('d.m.Y H:i', strtotime($original_date));
                        $new_fmt = date('d.m.Y H:i', strtotime($new_date));
                        $subject = "DoMiLi: Termin wurde verschoben!";
                        $body = "Hallo %s,\n\nDer Termin wurde vom Admin verschoben.\n\nUrsprünglicher Termin: %s\nNeuer Termin: %s\nGrund: %s\n\nBitte stimme erneut ab, ob du teilnehmen möchtest.\n\nZur Abstimmung: DoMiLi-APP\n%s\n\nDein DoMiLi-Team";

                        $users_stmt = mysqli_query($conn, "SELECT username, email FROM users WHERE email IS NOT NULL AND email != ''");
                        while ($u = mysqli_fetch_assoc($users_stmt)) {
                            $mail->addAddress($u['email']);
                            $mail->Subject = $subject;
                            $mail->Body = sprintf($body, $u['username'], $orig_fmt, $new_fmt, $new_reason, APP_URL . '/index.php');
                            $mail->send();
                            $mail->clearAddresses();
                        }
                    } catch (Exception $e) {
                        error_log("Fehler bei Akzeptanz-E-Mail: " . $mail->ErrorInfo);
                    }
                }
            }

            header("Location: index.php");
            exit;
        }

        // Admin: Vorschlag ablehnen → MIT KURZER E-MAIL
        if (isset($_POST['reject_proposal']) && isset($_POST['proposal_id'])) {
            $proposal_id = intval($_POST['proposal_id']);

            // Vorschlagdaten laden
            $proposal_stmt = mysqli_prepare($conn, "
                SELECT p.proposed_by_user_id, u.username AS proposer_name,
                       m.meeting_date AS original_date
                FROM meeting_reschedule_proposals p
                JOIN users u ON p.proposed_by_user_id = u.id
                JOIN meetings m ON p.meeting_id = m.id
                WHERE p.id = ?
            ");
            mysqli_stmt_bind_param($proposal_stmt, "i", $proposal_id);
            mysqli_stmt_execute($proposal_stmt);
            $proposal = mysqli_fetch_assoc(mysqli_stmt_get_result($proposal_stmt));
            mysqli_stmt_close($proposal_stmt);

            // Vorschlag ablehnen
            $reject_stmt = mysqli_prepare($conn, "
                UPDATE meeting_reschedule_proposals 
                SET status = 'rejected' 
                WHERE id = ?
            ");
            mysqli_stmt_bind_param($reject_stmt, "i", $proposal_id);
            mysqli_stmt_execute($reject_stmt);
            mysqli_stmt_close($reject_stmt);

            // ✉️ Kurze E-Mail nach Ablehnung
            if ($proposal && file_exists(__DIR__ . '/vendor/autoload.php')) {
                require_once __DIR__ . '/vendor/autoload.php';
                $mail = new \PHPMailer\PHPMailer\PHPMailer(true);
                $mail->CharSet = 'UTF-8';
                $mail->isHTML(false);

                try {
                    $mail->isSMTP();
                    $mail->Host       = SMTP_HOST;
                    $mail->SMTPAuth   = true;
                    $mail->Username   = SMTP_USERNAME;
                    $mail->Password   = SMTP_PASSWORD;
                    $mail->SMTPSecure = SMTP_ENCRYPTION;
                    $mail->Port       = SMTP_PORT;
                    $mail->setFrom(MAIL_FROM_ADDRESS, MAIL_FROM_NAME);

                    $proposer = $proposal['proposer_name'];
                    $original_fmt = date('d.m.Y H:i', strtotime($proposal['original_date']));
                    $subject = "DoMiLi: Verschiebungsvorschlag abgelehnt";
                    $body = "Hallo %s,\n\nDer Verschiebungsvorschlag von {$proposer} wurde vom Admin abgelehnt.\nDer Termin bleibt daher unverändert beim ursprünglichen Termin am {$original_fmt}.\n\nDein DoMiLi-Team";

                    $users_stmt = mysqli_query($conn, "SELECT username, email FROM users WHERE email IS NOT NULL AND email != ''");
                    while ($u = mysqli_fetch_assoc($users_stmt)) {
                        $mail->addAddress($u['email']);
                        $mail->Subject = $subject;
                        $mail->Body = sprintf($body, $u['username']);
                        $mail->send();
                        $mail->clearAddresses();
                    }
                } catch (Exception $e) {
                    error_log("Fehler bei Ablehnungs-E-Mail: " . $mail->ErrorInfo);
                }
            }

            header("Location: index.php");
            exit;
        }
    }
}