<?php

namespace Kirby\Cms;

use Closure;
use Kirby\Data\Data;
use Kirby\Exception\InvalidArgumentException;
use Kirby\Toolkit\Str;
use Throwable;

/**
 * ModelWithContent
 *
 * @package   Kirby Cms
 * @author    Bastian Allgeier <bastian@getkirby.com>
 * @link      https://getkirby.com
 * @copyright Bastian Allgeier GmbH
 * @license   https://getkirby.com/license
 */
abstract class ModelWithContent extends Model
{
    /**
     * Each model must define a CLASS_ALIAS
     * which will be used in template queries.
     * The CLASS_ALIAS is a short human-readable
     * version of the class name. I.e. page.
     */
    const CLASS_ALIAS = null;

    /**
     * The content
     *
     * @var \Kirby\Cms\Content
     */
    public $content;

    /**
     * @var \Kirby\Cms\Translations
     */
    public $translations;

    /**
     * Returns the blueprint of the model
     *
     * @return \Kirby\Cms\Blueprint
     */
    abstract public function blueprint();

    /**
     * Executes any given model action
     *
     * @param string $action
     * @param array $arguments
     * @param Closure $callback
     * @return mixed
     */
    abstract protected function commit(string $action, array $arguments, Closure $callback);

    /**
     * Returns the content
     *
     * @param string $languageCode
     * @return \Kirby\Cms\Content
     */
    public function content(string $languageCode = null)
    {

        // single language support
        if ($this->kirby()->multilang() === false) {
            if (is_a($this->content, 'Kirby\Cms\Content') === true) {
                return $this->content;
            }

            return $this->setContent($this->readContent())->content;

        // multi language support
        } else {

            // only fetch from cache for the default language
            if ($languageCode === null && is_a($this->content, 'Kirby\Cms\Content') === true) {
                return $this->content;
            }

            // get the translation by code
            if ($translation = $this->translation($languageCode)) {
                $content = new Content($translation->content(), $this);
            } else {
                throw new InvalidArgumentException('Invalid language: ' . $languageCode);
            }

            // only store the content for the current language
            if ($languageCode === null) {
                $this->content = $content;
            }

            return $content;
        }
    }

    /**
     * Returns the absolute path to the content file
     *
     * @internal
     * @param string|null $languageCode
     * @param bool $force
     * @return string
     */
    public function contentFile(string $languageCode = null, bool $force = false): string
    {
        $extension = $this->contentFileExtension();
        $directory = $this->contentFileDirectory();
        $filename  = $this->contentFileName();

        // overwrite the language code
        if ($force === true) {
            if (empty($languageCode) === false) {
                return $directory . '/' . $filename . '.' . $languageCode . '.' . $extension;
            } else {
                return $directory . '/' . $filename . '.' . $extension;
            }
        }

        // add and validate the language code in multi language mode
        if ($this->kirby()->multilang() === true) {
            if ($language = $this->kirby()->languageCode($languageCode)) {
                return $directory . '/' . $filename . '.' . $language . '.' . $extension;
            } else {
                throw new InvalidArgumentException('Invalid language: ' . $languageCode);
            }
        } else {
            return $directory . '/' . $filename . '.' . $extension;
        }
    }

    /**
     * Returns an array with all content files
     *
     * @return array
     */
    public function contentFiles(): array
    {
        if ($this->kirby()->multilang() === true) {
            $files = [];
            foreach ($this->kirby()->languages()->codes() as $code) {
                $files[] = $this->contentFile($code);
            }
            return $files;
        } else {
            return [
                $this->contentFile()
            ];
        }
    }

    /**
     * Prepares the content that should be written
     * to the text file
     *
     * @internal
     * @param array $data
     * @param string $languageCode
     * @return array
     */
    public function contentFileData(array $data, string $languageCode = null): array
    {
        return $data;
    }

    /**
     * Returns the absolute path to the
     * folder in which the content file is
     * located
     *
     * @internal
     * @return string|null
     */
    public function contentFileDirectory(): ?string
    {
        return $this->root();
    }

    /**
     * Returns the extension of the content file
     *
     * @internal
     * @return string
     */
    public function contentFileExtension(): string
    {
        return $this->kirby()->contentExtension();
    }

    /**
     * Needs to be declared by the final model
     *
     * @internal
     * @return string
     */
    abstract public function contentFileName(): string;

    /**
     * Decrement a given field value
     *
     * @param string $field
     * @param int $by
     * @param int $min
     * @return self
     */
    public function decrement(string $field, int $by = 1, int $min = 0)
    {
        $value = (int)$this->content()->get($field)->value() - $by;

        if ($value < $min) {
            $value = $min;
        }

        return $this->update([$field => $value]);
    }

    /**
     * Returns all content validation errors
     *
     * @return array
     */
    public function errors(): array
    {
        $errors = [];

        foreach ($this->blueprint()->sections() as $section) {
            if (method_exists($section, 'errors') === true || isset($section->errors)) {
                $errors = array_merge($errors, $section->errors());
            }
        }

        return $errors;
    }

    /**
     * Increment a given field value
     *
     * @param string $field
     * @param int $by
     * @param int $max
     * @return self
     */
    public function increment(string $field, int $by = 1, int $max = null)
    {
        $value = (int)$this->content()->get($field)->value() + $by;

        if ($max && $value > $max) {
            $value = $max;
        }

        return $this->update([$field => $value]);
    }

    /**
     * Checks if the model is locked for the current user
     *
     * @return bool
     */
    public function isLocked(): bool
    {
        $lock = $this->lock();
        return $lock && $lock->isLocked() === true;
    }

    /**
     * Checks if the data has any errors
     *
     * @return bool
     */
    public function isValid(): bool
    {
        return Form::for($this)->hasErrors() === false;
    }

    /**
     * Returns the lock object for this model
     *
     * Only if a content directory exists,
     * virtual pages will need to overwrite this method
     *
     * @return \Kirby\Cms\ContentLock|null
     */
    public function lock()
    {
        $dir = $this->contentFileDirectory();

        if (
            $this->kirby()->option('content.locking', true) &&
            is_string($dir) === true &&
            file_exists($dir) === true
        ) {
            return new ContentLock($this);
        }
    }

    /**
     * Returns the panel icon definition
     *
     * @internal
     * @param array $params
     * @return array
     */
    public function panelIcon(array $params = null): array
    {
        $defaults = [
            'type'  => 'page',
            'ratio' => null,
            'back'  => 'pattern',
            'color' => '#c5c9c6',
        ];

        return array_merge($defaults, $params ?? []);
    }

    /**
     * @internal
     * @param string|array|false $settings
     * @return array|null
     */
    public function panelImage($settings = null): ?array
    {
        $defaults = [
            'ratio' => '3/2',
            'back'  => 'pattern',
            'cover' => false
        ];

        // switch the image off
        if ($settings === false) {
            return null;
        }

        if (is_string($settings) === true) {
            $settings = [
                'query' => $settings
            ];
        }

        if ($image = $this->panelImageSource($settings['query'] ?? null)) {

            // main url
            $settings['url'] = $image->url();

            // for cards
            $settings['cards'] = [
                'url' => 'data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw',
                'srcset' => $image->srcset([
                    352,
                    864,
                    1408,
                ])
            ];

            // for lists
            $settings['list'] = [
                'url' => 'data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw',
                'srcset' => $image->srcset([
                    '1x' => [
                        'width' => 38,
                        'height' => 38,
                        'crop' => 'center'
                    ],
                    '2x' => [
                        'width' => 76,
                        'height' => 76,
                        'crop' => 'center'
                    ],
                ])
            ];

            unset($settings['query']);
        }

        return array_merge($defaults, (array)$settings);
    }

    /**
     * Returns the image file object based on provided query
     *
     * @internal
     * @param string|null $query
     * @return \Kirby\Cms\File|\Kirby\Cms\Asset|null
     */
    protected function panelImageSource(string $query = null)
    {
        $image = $this->query($query ?? null);

        // validate the query result
        if (is_a($image, 'Kirby\Cms\File') === false && is_a($image, 'Kirby\Cms\Asset') === false) {
            $image = null;
        }

        // fallback for files
        if ($image === null && is_a($this, 'Kirby\Cms\File') === true && $this->isViewable() === true) {
            $image = $this;
        }

        return $image;
    }

    /**
     * Returns an array of all actions
     * that can be performed in the Panel
     * This also checks for the lock status
     * @since 3.3.0
     *
     * @param array $unlock An array of options that will be force-unlocked
     * @return array
     */
    public function panelOptions(array $unlock = []): array
    {
        $options = $this->permissions()->toArray();

        if ($this->isLocked()) {
            foreach ($options as $key => $value) {
                if (in_array($key, $unlock)) {
                    continue;
                }

                $options[$key] = false;
            }
        }

        return $options;
    }

    /**
     * Must return the permissions object for the model
     *
     * @return \Kirby\Cms\ModelPermissions
     */
    abstract public function permissions();

    /**
     * Creates a string query, starting from the model
     *
     * @internal
     * @param string|null $query
     * @param string|null $expect
     * @return mixed
     */
    public function query(string $query = null, string $expect = null)
    {
        if ($query === null) {
            return null;
        }

        $result = Str::query($query, [
            'kirby'             => $this->kirby(),
            'site'              => is_a($this, 'Kirby\Cms\Site') ? $this : $this->site(),
            static::CLASS_ALIAS => $this
        ]);

        if ($expect !== null && is_a($result, $expect) !== true) {
            return null;
        }

        return $result;
    }

    /**
     * Read the content from the content file
     *
     * @internal
     * @param string|null $languageCode
     * @return array
     */
    public function readContent(string $languageCode = null): array
    {
        try {
            return Data::read($this->contentFile($languageCode));
        } catch (Throwable $e) {
            return [];
        }
    }

    /**
     * Returns the absolute path to the model
     *
     * @return string|null
     */
    abstract public function root(): ?string;

    /**
     * Stores the content on disk
     *
     * @internal
     * @param string $languageCode
     * @param array $data
     * @param bool $overwrite
     * @return self
     */
    public function save(array $data = null, string $languageCode = null, bool $overwrite = false)
    {
        if ($this->kirby()->multilang() === true) {
            return $this->saveTranslation($data, $languageCode, $overwrite);
        } else {
            return $this->saveContent($data, $overwrite);
        }
    }

    /**
     * Save the single language content
     *
     * @param array|null $data
     * @param bool $overwrite
     * @return self
     */
    protected function saveContent(array $data = null, bool $overwrite = false)
    {
        // create a clone to avoid modifying the original
        $clone = $this->clone();

        // merge the new data with the existing content
        $clone->content()->update($data, $overwrite);

        // send the full content array to the writer
        $clone->writeContent($clone->content()->toArray());

        return $clone;
    }

    /**
     * Save a translation
     *
     * @param array|null $data
     * @param string|null $languageCode
     * @param bool $overwrite
     * @return self
     */
    protected function saveTranslation(array $data = null, string $languageCode = null, bool $overwrite = false)
    {
        // create a clone to not touch the original
        $clone = $this->clone();

        // fetch the matching translation and update all the strings
        $translation = $clone->translation($languageCode);

        if ($translation === null) {
            throw new InvalidArgumentException('Invalid language: ' . $languageCode);
        }

        // get the content to store
        $content      = $translation->update($data, $overwrite)->content();
        $kirby        = $this->kirby();
        $languageCode = $kirby->languageCode($languageCode);

        // remove all untranslatable fields
        if ($languageCode !== $kirby->defaultLanguage()->code()) {
            foreach ($this->blueprint()->fields() as $field) {
                if (($field['translate'] ?? true) === false) {
                    $content[$field['name']] = null;
                }
            }

            // merge the translation with the new data
            $translation->update($content, true);
        }

        // send the full translation array to the writer
        $clone->writeContent($translation->content(), $languageCode);

        // reset the content object
        $clone->content = null;

        // return the updated model
        return $clone;
    }

    /**
     * Sets the Content object
     *
     * @param array|null $content
     * @return self
     */
    protected function setContent(array $content = null)
    {
        if ($content !== null) {
            $content = new Content($content, $this);
        }

        $this->content = $content;
        return $this;
    }

    /**
     * Create the translations collection from an array
     *
     * @param array $translations
     * @return self
     */
    protected function setTranslations(array $translations = null)
    {
        if ($translations !== null) {
            $this->translations = new Collection();

            foreach ($translations as $props) {
                $props['parent'] = $this;
                $translation = new ContentTranslation($props);
                $this->translations->data[$translation->code()] = $translation;
            }
        }

        return $this;
    }

    /**
     * String template builder
     *
     * @param string|null $template
     * @return string
     */
    public function toString(string $template = null): string
    {
        if ($template === null) {
            return $this->id();
        }

        $result = Str::template($template, [
            'kirby'             => $this->kirby(),
            'site'              => is_a($this, 'Kirby\Cms\Site') ? $this : $this->site(),
            static::CLASS_ALIAS => $this
        ]);

        return $result;
    }

    /**
     * Returns a single translation by language code
     * If no code is specified the current translation is returned
     *
     * @param string|null $languageCode
     * @return \Kirby\Cms\ContentTranslation|null
     */
    public function translation(string $languageCode = null)
    {
        return $this->translations()->find($languageCode ?? $this->kirby()->language()->code());
    }

    /**
     * Returns the translations collection
     *
     * @return \Kirby\Cms\Collection
     */
    public function translations()
    {
        if ($this->translations !== null) {
            return $this->translations;
        }

        $this->translations = new Collection();

        foreach ($this->kirby()->languages() as $language) {
            $translation = new ContentTranslation([
                'parent' => $this,
                'code'   => $language->code(),
            ]);

            $this->translations->data[$translation->code()] = $translation;
        }

        return $this->translations;
    }

    /**
     * Updates the model data
     *
     * @param array $input
     * @param string $languageCode
     * @param bool $validate
     * @return self
     */
    public function update(array $input = null, string $languageCode = null, bool $validate = false)
    {
        $form = Form::for($this, [
            'ignoreDisabled' => $validate === false,
            'input'          => $input,
            'language'       => $languageCode,
        ]);

        // validate the input
        if ($validate === true) {
            if ($form->isInvalid() === true) {
                throw new InvalidArgumentException([
                    'fallback' => 'Invalid form with errors',
                    'details'  => $form->errors()
                ]);
            }
        }

        return $this->commit('update', [$this, $form->data(), $form->strings(), $languageCode], function ($model, $values, $strings, $languageCode) {
            // save updated values
            $model = $model->save($strings, $languageCode, true);

            // update model in siblings collection
            $model->siblings()->add($model);

            return $model;
        });
    }

    /**
     * Low level data writer method
     * to store the given data on disk or anywhere else
     *
     * @internal
     * @param array $data
     * @param string $languageCode
     * @return bool
     */
    public function writeContent(array $data, string $languageCode = null): bool
    {
        return Data::write(
            $this->contentFile($languageCode),
            $this->contentFileData($data, $languageCode)
        );
    }
}