<?php

use Carbon\CarbonTimeZone;
use Engelsystem\Http\Exceptions\HttpForbidden;
use Engelsystem\Models\AngelType;
use Engelsystem\Models\Shifts\ScheduleShift;
use Engelsystem\Models\Shifts\Shift;
use Engelsystem\Models\Shifts\ShiftType;
use Engelsystem\Models\User\User;
use Engelsystem\ShiftSignupState;
use Illuminate\Support\Collection;

/**
 * @param array|Shift $shift
 * @return string
 */
function shift_link($shift)
{
    $parameters = ['action' => 'view'];
    if (isset($shift['shift_id']) || isset($shift['id'])) {
        $parameters['shift_id'] = $shift['shift_id'] ?? $shift['id'];
    }

    return page_link_to('shifts', $parameters);
}

/**
 * @param Shift $shift
 * @return string
 */
function shift_delete_link(Shift $shift)
{
    return page_link_to('user_shifts', ['delete_shift' => $shift->id]);
}

/**
 * @param Shift $shift
 * @return string
 */
function shift_edit_link(Shift $shift)
{
    return page_link_to('user_shifts', ['edit_shift' => $shift->id]);
}

/**
 * Edit a single shift.
 *
 * @return string
 */
function shift_edit_controller()
{
    $valid = true;
    $request = request();

    if (!auth()->can('admin_shifts')) {
        throw_redirect(page_link_to('user_shifts'));
    }

    if (!$request->has('edit_shift') || !test_request_int('edit_shift')) {
        throw_redirect(page_link_to('user_shifts'));
    }
    $shift_id = $request->input('edit_shift');

    $shift = Shift(Shift::findOrFail($shift_id));
    if (ScheduleShift::whereShiftId($shift->id)->first()) {
        warning(__(
            'This shift was imported from a schedule so some changes will be overwritten with the next import.'
        ));
    }

    $rooms = [];
    foreach (Rooms() as $room) {
        $rooms[$room->id] = $room->name;
    }
    $angeltypes = AngelType::all()->pluck('name', 'id')->toArray();
    $shifttypes = ShiftType::all()->pluck('name', 'id')->toArray();

    $needed_angel_types = collect(NeededAngelTypes_by_shift($shift_id))->pluck('count', 'angel_type_id')->toArray();
    foreach (array_keys($angeltypes) as $angeltype_id) {
        if (!isset($needed_angel_types[$angeltype_id])) {
            $needed_angel_types[$angeltype_id] = 0;
        }
    }

    $shifttype_id = $shift->shift_type_id;
    $title = $shift->title;
    $description = $shift->description;
    $rid = $shift->room_id;
    $start = $shift->start;
    $end = $shift->end;

    if ($request->hasPostData('submit')) {
        // Name/Bezeichnung der Schicht, darf leer sein
        $title = strip_request_item('title');
        $description = strip_request_item_nl('description');

        // Auswahl der sichtbaren Locations für die Schichten
        if (
            $request->has('rid')
            && preg_match('/^\d+$/', $request->input('rid'))
            && isset($rooms[$request->input('rid')])
        ) {
            $rid = $request->input('rid');
        } else {
            $valid = false;
            error(__('Please select a room.'));
        }

        if ($request->has('shifttype_id') && isset($shifttypes[$request->input('shifttype_id')])) {
            $shifttype_id = $request->input('shifttype_id');
        } else {
            $valid = false;
            error(__('Please select a shifttype.'));
        }

        if ($request->has('start') && $tmp = DateTime::createFromFormat('Y-m-d H:i', $request->input('start'))) {
            $start = $tmp;
        } else {
            $valid = false;
            error(__('Please enter a valid starting time for the shifts.'));
        }

        if ($request->has('end') && $tmp = DateTime::createFromFormat('Y-m-d H:i', $request->input('end'))) {
            $end = $tmp;
        } else {
            $valid = false;
            error(__('Please enter a valid ending time for the shifts.'));
        }

        if ($start >= $end) {
            $valid = false;
            error(__('The ending time has to be after the starting time.'));
        }

        foreach ($needed_angel_types as $needed_angeltype_id => $count) {
            $needed_angel_types[$needed_angeltype_id] = 0;

            $queryKey = 'angeltype_count_' . $needed_angeltype_id;
            if ($request->has($queryKey)) {
                if (test_request_int($queryKey)) {
                    $needed_angel_types[$needed_angeltype_id] = trim($request->input($queryKey));
                } else {
                    $valid = false;
                    error(sprintf(
                        __('Please check your input for needed angels of type %s.'),
                        $angeltypes[$needed_angeltype_id]
                    ));
                }
            }
        }

        if ($valid) {
            $shift->shift_type_id = $shifttype_id;
            $shift->title = $title;
            $shift->description = $description;
            $shift->room_id = $rid;
            $shift->start = $start;
            $shift->end = $end;
            $shift->updatedBy()->associate(auth()->user());

            // Remove merged data as it is not really part of the model and thus can't be saved
            unset($shift->shiftEntry);
            unset($shift->neededAngels);

            $shift->save();

            mail_shift_change(Shift($shift->id), $shift);

            NeededAngelTypes_delete_by_shift($shift_id);
            $needed_angel_types_info = [];
            foreach ($needed_angel_types as $type_id => $count) {
                NeededAngelType_add($shift_id, $type_id, null, $count);
                if ($count > 0) {
                    $needed_angel_types_info[] = $angeltypes[$type_id] . ': ' . $count;
                }
            }

            engelsystem_log(
                'Updated shift \'' . $shifttypes[$shifttype_id] . ', ' . $title
                . '\' from ' . $start->format('Y-m-d H:i')
                . ' to ' . $end->format('Y-m-d H:i')
                . ' with angel types ' . join(', ', $needed_angel_types_info)
                . ' and description ' . $description
            );
            success(__('Shift updated.'));

            throw_redirect(shift_link($shift));
        }
    }

    $angel_types_spinner = '';
    foreach ($angeltypes as $angeltype_id => $angeltype_name) {
        $angel_types_spinner .= form_spinner(
            'angeltype_count_' . $angeltype_id,
            $angeltype_name,
            $needed_angel_types[$angeltype_id]
        );
    }

    return page_with_title(
        shifts_title(),
        [
            msg(),
            '<noscript>'
            . info(__('This page is much more comfortable with javascript.'), true)
            . '</noscript>',
            form([
                form_select('shifttype_id', __('Shifttype'), $shifttypes, $shifttype_id),
                form_text('title', __('Title'), $title),
                form_select('rid', __('Room:'), $rooms, $rid),
                form_text('start', __('Start:'), $start->format('Y-m-d H:i')),
                form_text('end', __('End:'), $end->format('Y-m-d H:i')),
                form_textarea('description', __('Additional description'), $description),
                form_info('', __('This description is for single shifts, otherwise please use the description in shift type.')),
                '<h2>' . __('Needed angels') . '</h2>',
                $angel_types_spinner,
                form_submit('submit', __('Save'))
            ])
        ]
    );
}

/**
 * @return string
 */
function shift_delete_controller()
{
    $request = request();

    if (!auth()->can('user_shifts_admin')) {
        throw_redirect(page_link_to('user_shifts'));
    }

    // Schicht komplett löschen (nur für admins/user mit user_shifts_admin privileg)
    if (!$request->has('delete_shift') || !preg_match('/^\d+$/', $request->input('delete_shift'))) {
        throw_redirect(page_link_to('user_shifts'));
    }
    $shift_id = $request->input('delete_shift');

    $shift = Shift($shift_id);
    if (empty($shift)) {
        throw_redirect(page_link_to('user_shifts'));
    }

    // Schicht löschen bestätigt
    if ($request->hasPostData('delete')) {
        foreach ($shift->shiftEntry as $entry) {
            $type = AngelType::find($entry['TID']);
            event('shift.entry.deleting', [
                'user'       => User::find($entry['user_id']),
                'start'      => $shift->start,
                'end'        => $shift->end,
                'name'       => $shift->shiftType->name,
                'title'      => $shift->title,
                'type'       => $type->name,
                'room'       => $shift->room,
                'freeloaded' => (bool) $entry['freeloaded'],
            ]);
        }

        $shift->delete();

        engelsystem_log(
            'Deleted shift ' . $shift->title . ': ' .  $shift->shiftType->name
            . ' from ' . $shift->start->format('Y-m-d H:i')
            . ' to ' . $shift->end->format('Y-m-d H:i')
        );
        success(__('Shift deleted.'));
        throw_redirect(page_link_to('user_shifts'));
    }

    return page_with_title(shifts_title(), [
        error(sprintf(
            __('Do you want to delete the shift %s from %s to %s?'),
            $shift->shiftType->name,
            $shift->start->format('Y-m-d H:i'),
            $shift->end->format('H:i')
        ), true),
        form([
            form_hidden('delete_shift', $shift->id),
            form_submit('delete', __('delete')),
        ]),
    ]);
}

/**
 * @return array
 */
function shift_controller()
{
    $user = auth()->user();
    $request = request();

    if (!auth()->can('user_shifts')) {
        throw_redirect(page_link_to('/'));
    }

    if (!$request->has('shift_id')) {
        throw_redirect(page_link_to('user_shifts'));
    }

    $shift = Shift($request->input('shift_id'));
    if (empty($shift)) {
        error(__('Shift could not be found.'));
        throw_redirect(page_link_to('user_shifts'));
    }

    $shifttype = $shift->shiftType;
    $room = $shift->room;
    /** @var AngelType[] $angeltypes */
    $angeltypes = AngelType::all();
    $user_shifts = Shifts_by_user($user->id);

    $shift_signup_state = new ShiftSignupState(ShiftSignupState::OCCUPIED, 0);
    foreach ($angeltypes as $angeltype) {
        $needed_angeltype = NeededAngeltype_by_Shift_and_Angeltype($shift, $angeltype);
        if (empty($needed_angeltype)) {
            continue;
        }

        $shift_entries = ShiftEntries_by_shift_and_angeltype($shift->id, $angeltype->id);
        $needed_angeltype = (new AngelType())->forceFill($needed_angeltype);

        $angeltype_signup_state = Shift_signup_allowed(
            $user,
            $shift,
            $angeltype,
            null,
            $user_shifts,
            $needed_angeltype,
            $shift_entries
        );
        $shift_signup_state->combineWith($angeltype_signup_state);
        $angeltype->shift_signup_state = $angeltype_signup_state;
    }

    return [
        $shift->shiftType->name,
        Shift_view($shift, $shifttype, $room, $angeltypes, $shift_signup_state)
    ];
}

/**
 * @return array
 */
function shifts_controller()
{
    $request = request();
    if (!$request->has('action')) {
        throw_redirect(page_link_to('user_shifts'));
    }

    return match ($request->input('action')) {
        'view'  => shift_controller(),
        'next'  => shift_next_controller(), // throws redirect
        default => throw_redirect(page_link_to('/')),
    };
}

/**
 * Redirects the user to his next shift.
 */
function shift_next_controller()
{
    if (!auth()->can('user_shifts')) {
        throw_redirect(page_link_to('/'));
    }

    $upcoming_shifts = ShiftEntries_upcoming_for_user(auth()->user());

    if (!empty($upcoming_shifts)) {
        throw_redirect(shift_link($upcoming_shifts[0]));
    }

    throw_redirect(page_link_to('user_shifts'));
}

/**
 * Export filtered shifts via JSON.
 * (Like iCal Export or shifts view)
 */
function shifts_json_export_controller()
{
    $request = request();
    $user = auth()->apiUser('key');

    if (
        !$request->has('key')
        || !$request->input('key')
        || !$user
    ) {
        throw new HttpForbidden('{"error":"Missing or invalid key"}', ['content-type' => 'application/json']);
    }

    if (!auth()->can('shifts_json_export')) {
        throw new HttpForbidden('{"error":"Not allowed"}', ['content-type' => 'application/json']);
    }

    $shifts = load_ical_shifts();
    $shifts->sortBy('start_date');
    $timeZone = CarbonTimeZone::create(config('timezone'));

    $shiftsData = [];
    foreach ($shifts as $shift) {
        // Data required for the Fahrplan app integration https://github.com/johnjohndoe/engelsystem
        // See engelsystem-base/src/main/kotlin/info/metadude/kotlin/library/engelsystem/models/Shift.kt
        $data = [
            // Name of the shift (type)
            'name' => $shift->shiftType->name,
            // Shift / Talk title
            'title' => $shift->title,
            // Shift description
            'description' => $shift->description,

            // Users comment
            'Comment' => $shift->Comment,

            // Shift id
            'SID' => $shift->id,
            // Shift type id
            'shifttype_id' => $shift->shift_type_id,
            // Talk URL
            'URL' => $shift->url,

            // Room name
            'Name' => $shift->room->name,
            // Location map url
            'map_url' => $shift->room->map_url,

            // Start timestamp
            /** @deprecated start_date should be used */
            'start' => $shift->start->timestamp,
            // Start date
            'start_date' => $shift->start->toRfc3339String(),
            // End timestamp
            /** @deprecated end_date should be used */
            'end' => $shift->end->timestamp,
            // End date
            'end_date' => $shift->end->toRfc3339String(),

            // Timezone offset like "+01:00"
            /** @deprecated should be retrieved from start_date or end_date */
            'timezone' => $timeZone->toOffsetName(),
            // The events timezone like "Europe/Berlin"
            'event_timezone' => $timeZone->getName(),
        ];

        $shiftsData[] = [
            // Model data
            ...$shift->toArray(),

            // legacy fields (ignoring created / updated (at/by) data)
            'RID' => $shift->room_id,

            // Fahrplan app required data
            ...$data
        ];
    }

    header('Content-Type: application/json; charset=utf-8');
    raw_output(json_encode($shiftsData));
}

/**
 * Returns users shifts to export.
 *
 * @return Shift[]|Collection
 */
function load_ical_shifts()
{
    return Shifts_by_user(auth()->user()->id);
}