<?php

namespace NoNameWeb\LivewireMaterial\Console;

use Illuminate\Console\Command;
use Illuminate\Filesystem\Filesystem;
use Illuminate\Support\Facades\Process;
use Illuminate\Support\Str;
use JsonException;
use Symfony\Component\Console\Attribute\AsCommand;

#[AsCommand(name: 'material:scheme')]
class SchemeCommand extends Command
{
    /**
     * @var string
     */
    protected $signature = 'material:scheme
        {seed? : The source colour, as #rrggbb; without it, every profile in livewire-material.profiles}
        {--variant=tonal-spot : tonal-spot, vibrant, expressive, neutral, fidelity, content, monochrome, rainbow or fruit-salad}
        {--contrast=0 : The contrast level, from -1 to 1}
        {--success=#22a06b : The source of the success colour}
        {--warning=#e2a400 : The source of the warning colour}
        {--info=#1d7afc : The source of the info colour}
        {--output= : The stylesheet to write, resources/css/material-scheme.css by default}';

    /**
     * @var string
     */
    protected $description = 'Generate the application\'s Material 3 colour scheme from a seed colour, or every configured colour profile';

    public function handle(Filesystem $files): int
    {
        $stylesheet = $this->option('output') ?: resource_path('css/material-scheme.css');
        $data = preg_replace('/\.css$/', '', $stylesheet).'.json';

        if (filled($this->argument('seed'))) {
            $scheme = $this->generate((string) $this->argument('seed'), (string) $this->option('variant'), (float) $this->option('contrast'));

            if ($scheme === null) {
                return self::FAILURE;
            }

            return $this->write($files, $stylesheet, $data, $this->stylesheet($scheme), $scheme);
        }

        $profiles = config('livewire-material.profiles');

        if (! is_array($profiles) || $profiles === []) {
            $this->components->error('Give a seed colour (php artisan material:scheme "#4f46e5"), or list colour profiles in livewire-material.profiles.');

            return self::FAILURE;
        }

        $generated = [];

        foreach ($profiles as $name => $profile) {
            if (! is_string($name) || preg_match('/^[a-z0-9-]+$/', $name) !== 1) {
                $this->components->error("A profile's name is lowercase letters, digits and dashes; \"{$name}\" is not.");

                return self::FAILURE;
            }

            $scheme = $this->generate((string) ($profile['seed'] ?? ''), (string) ($profile['variant'] ?? 'tonal-spot'), (float) ($profile['contrast'] ?? 0), "Profile \"{$name}\": ");

            if ($scheme === null) {
                return self::FAILURE;
            }

            $generated[$name] = ['label' => (string) ($profile['label'] ?? Str::headline($name)), ...$scheme];
        }

        $configured = config('livewire-material.profile');
        $default = is_string($configured) && isset($generated[$configured]) ? $configured : array_key_first($generated);

        return $this->write($files, $stylesheet, $data, $this->profilesStylesheet($generated, $default), [
            ...collect($generated[$default])->except('label')->all(),
            'default' => $default,
            'profiles' => $generated,
        ]);
    }

    /**
     * One scheme from Google's colour utilities, or null once the reason has been shown.
     *
     * @return array{seed: string, variant: string, spec: string, contrast: float, light: array<string, string>, dark: array<string, string>}|null
     */
    protected function generate(string $seed, string $variant, float $contrast, string $context = ''): ?array
    {
        $result = Process::run([
            config('livewire-material.node', 'node'),
            __DIR__.'/../../resources/node/scheme.mjs',
            json_encode([
                'seed' => $seed,
                'variant' => $variant,
                'contrast' => $contrast,
                'success' => $this->option('success'),
                'warning' => $this->option('warning'),
                'info' => $this->option('info'),
            ]),
        ]);

        if ($result->failed()) {
            $this->components->error($context.(trim($result->errorOutput()) ?: 'Node could not run the scheme generator. Is `node` installed and on the PATH?'));

            return null;
        }

        try {
            return json_decode($result->output(), true, flags: JSON_THROW_ON_ERROR);
        } catch (JsonException) {
            $this->components->error($context.'The scheme generator answered with something other than JSON.');

            return null;
        }
    }

    /**
     * @param  array<string, mixed>  $scheme
     */
    protected function write(Filesystem $files, string $stylesheet, string $data, string $css, array $scheme): int
    {
        $files->ensureDirectoryExists(dirname($stylesheet));
        $files->put($stylesheet, $css);
        $files->put($data, json_encode($scheme, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES)."\n");

        $this->components->info("Wrote {$stylesheet} and {$data}.");

        return self::SUCCESS;
    }

    /**
     * @param  array{seed: string, variant: string, spec: string, contrast: float, light: array<string, string>, dark: array<string, string>}  $scheme
     */
    protected function stylesheet(array $scheme): string
    {
        $command = sprintf(
            'php artisan material:scheme "%s" --variant=%s%s',
            $scheme['seed'],
            $scheme['variant'],
            $scheme['contrast'] != 0 ? ' --contrast='.$scheme['contrast'] : '',
        );

        $blocks = $this->blocks([':root', "[data-theme='light']"], ["[data-theme='dark']"], $scheme);

        return <<<CSS
        /*
         * Material 3 colour roles, generated by Google's material-color-utilities (spec {$scheme['spec']}).
         *
         *     {$command}
         *
         * Regenerate rather than editing a value: every pair here (a role and its on-role) carries
         * M3's contrast guarantee only as generated. The head script sets data-theme before the
         * first paint; the light block also stands without it.
         */

        {$blocks}
        CSS;
    }

    /**
     * The default profile as the plain blocks, then every profile under its own data-scheme. A
     * profile's two-attribute selectors outrank the plain ones, and its one-attribute selector
     * comes after `:root`, which it only ties with: the order is part of the format. The
     * descendant selectors keep a nested `data-theme` panel (a light card on a dark page) in the
     * page's profile.
     *
     * @param  array<string, array{label: string, seed: string, variant: string, spec: string, contrast: float, light: array<string, string>, dark: array<string, string>}>  $profiles
     */
    protected function profilesStylesheet(array $profiles, string $default): string
    {
        $list = collect($profiles)
            ->map(fn (array $profile, string $name): string => sprintf(
                ' *     %-12s %s, %s%s',
                $name,
                $profile['seed'],
                $profile['variant'],
                $profile['contrast'] != 0 ? ', contrast '.$profile['contrast'] : '',
            ))
            ->implode("\n");

        $css = <<<CSS
        /*
         * Material 3 colour profiles, generated by Google's material-color-utilities (spec {$profiles[$default]['spec']}).
         *
         *     php artisan material:scheme
         *
         * From livewire-material.profiles. "{$default}" is the default, and also stands without a
         * data-scheme attribute:
         *
        {$list}
         *
         * Regenerate rather than editing a value: every pair here (a role and its on-role) carries
         * M3's contrast guarantee only as generated. The head script sets data-theme and data-scheme
         * before the first paint.
         */

        CSS;

        $css .= "\n".$this->blocks([':root', "[data-theme='light']"], ["[data-theme='dark']"], $profiles[$default]);

        foreach ($profiles as $name => $profile) {
            $css .= "\n".$this->blocks(
                ["[data-scheme='{$name}']", "[data-scheme='{$name}'][data-theme='light']", "[data-scheme='{$name}'] [data-theme='light']"],
                ["[data-scheme='{$name}'][data-theme='dark']", "[data-scheme='{$name}'] [data-theme='dark']"],
                $profile,
            );
        }

        return $css;
    }

    /**
     * A light and a dark block of roles under the given selectors.
     *
     * @param  list<string>  $light
     * @param  list<string>  $dark
     * @param  array{light: array<string, string>, dark: array<string, string>}  $scheme
     */
    protected function blocks(array $light, array $dark, array $scheme): string
    {
        $roles = fn (array $roles): string => collect($roles)
            ->map(fn (string $hex, string $role): string => "    --md-sys-color-{$role}: {$hex};")
            ->implode("\n");

        return implode(",\n", $light)." {\n    color-scheme: light;\n\n".$roles($scheme['light'])."\n}\n\n"
            .implode(",\n", $dark)." {\n    color-scheme: dark;\n\n".$roles($scheme['dark'])."\n}\n";
    }
}