<?php

namespace Toolbox;

final class Manifest
{
    /**
     * @param array<string, Component> $components
     * @param list<string>             $default
     */
    private function __construct(
        public readonly string $name,
        public readonly string $version,
        public readonly string $description,
        private readonly array $components,
        private readonly ?array $default,
        public readonly ?string $coreRequires,
        public readonly ?string $coreTested,
        public readonly ?string $php,
        public readonly array $postInstall,
        public readonly ?bool $coreIndependent = null,
    ) {
    }

    public static function fromFile(string $path): self
    {
        if (!is_file($path)) {
            throw new ToolboxException("No se encontró el manifiesto: {$path}");
        }

        $data = json_decode((string) file_get_contents($path), true);
        if (!is_array($data)) {
            throw new ToolboxException("Manifiesto JSON inválido: {$path}");
        }

        return self::fromArray($data, $path);
    }

    public static function fromArray(array $data, string $origin = 'duckbrain.json'): self
    {
        $name    = $data['name'] ?? null;
        $version = $data['version'] ?? null;

        if (!is_string($name) || $name === '') {
            throw new ToolboxException("El manifiesto '{$origin}' no declara 'name'");
        }

        if (!is_string($version) || $version === '') {
            throw new ToolboxException("El manifiesto '{$origin}' no declara 'version'");
        }

        Semver::parse($version);

        if (!isset($data['components']) || !is_array($data['components']) || $data['components'] === []) {
            throw new ToolboxException("El manifiesto '{$origin}' no declara 'components'");
        }

        $components = [];
        foreach ($data['components'] as $componentName => $componentData) {
            if (!is_string($componentName) || !is_array($componentData)) {
                throw new ToolboxException("Componente inválido en '{$origin}'");
            }
            $components[$componentName] = Component::fromArray($componentName, $componentData);
        }

        $default = null;
        if (array_key_exists('default', $data)) {
            if (!is_array($data['default'])) {
                throw new ToolboxException("El manifiesto '{$origin}' tiene 'default' inválido");
            }
            $default = array_values($data['default']);
            foreach ($default as $componentName) {
                if (!is_string($componentName) || !isset($components[$componentName])) {
                    throw new ToolboxException("'default' referencia un componente inexistente en '{$origin}'");
                }
            }
        }

        $postInstall = [];
        foreach (($data['post-install'] ?? []) as $command) {
            if (!is_string($command)) {
                throw new ToolboxException("'post-install' inválido en '{$origin}'");
            }
            $postInstall[] = $command;
        }

        $coreRequires = $coreTested = null;
        $coreIndependent = null;
        if (array_key_exists('core', $data)) {
            [$coreRequires, $coreTested, $coreIndependent] = Component::parseCore($data['core'], "el manifiesto '{$origin}'");
        }

        return new self(
            name: $name,
            version: $version,
            description: is_string($data['description'] ?? null) ? $data['description'] : '',
            components: $components,
            default: $default,
            coreRequires: $coreRequires,
            coreTested: $coreTested,
            php: is_string($data['php'] ?? null) ? $data['php'] : null,
            postInstall: $postInstall,
            coreIndependent: $coreIndependent,
        );
    }

    /** @return array<string, Component> */
    public function components(): array
    {
        return $this->components;
    }

    public function hasComponent(string $name): bool
    {
        return isset($this->components[$name]);
    }

    public function component(string $name): Component
    {
        if (!isset($this->components[$name])) {
            throw new ToolboxException("El paquete '{$this->name}' no tiene el componente '{$name}'");
        }

        return $this->components[$name];
    }

    /**
     * Expande una petición (componente o conjunto por defecto) a nombres.
     *
     * @return list<string>
     */
    public function expand(?string $component): array
    {
        if ($component !== null) {
            if (!$this->hasComponent($component)) {
                throw new ToolboxException("El paquete '{$this->name}' no tiene el componente '{$component}'");
            }

            return [$component];
        }

        if ($this->default === null) {
            throw new ToolboxException(
                "El paquete '{$this->name}' no declara 'default'; indica un componente explícito"
            );
        }

        return $this->default;
    }

    /**
     * Bloque de core efectivo: si el componente declara `core` (rango o
     * "none") ese bloque gana por completo; si no, hereda el del paquete.
     *
     * @return array{requires: ?string, tested: ?string, independent: ?bool}
     */
    private function coreBlock(?string $component): array
    {
        if ($component !== null) {
            $c = $this->component($component);
            if ($c->coreDeclared) {
                return ['requires' => $c->coreRequires, 'tested' => $c->coreTested, 'independent' => $c->coreIndependent];
            }
        }

        return ['requires' => $this->coreRequires, 'tested' => $this->coreTested, 'independent' => $this->coreIndependent];
    }

    public function coreRequirement(?string $component = null): ?string
    {
        return $this->coreBlock($component)['requires'];
    }

    public function testedCore(?string $component = null): ?string
    {
        return $this->coreBlock($component)['tested'];
    }

    public function coreIndependent(?string $component = null): bool
    {
        return $this->coreBlock($component)['independent'] === true;
    }

    /**
     * Descripcion efectiva: la propia del componente o, en su ausencia, la del
     * paquete (mismo patrón de herencia que los rangos de core).
     */
    public function descriptionOf(?string $component = null): ?string
    {
        if ($component !== null) {
            return $this->component($component)->description ?? $this->description;
        }

        return $this->description;
    }
}