<?php

declare(strict_types=1);

namespace KTXM\ProviderImap\Client;

final class MessagePart
{
    /**
     * @param array<string, string> $parameters
     * @param array<string, string> $dispositionParameters
     * @param list<string> $language
     * @param list<MessagePart> $parts
     */
    public function __construct(
        private readonly string $partId,
        private readonly string $mimeType,
        private readonly array $parameters = [],
        private readonly ?string $contentId = null,
        private readonly ?string $description = null,
        private readonly ?string $encoding = null,
        private readonly ?int $size = null,
        private readonly ?string $disposition = null,
        private readonly array $dispositionParameters = [],
        private readonly array $language = [],
        private readonly ?string $location = null,
        private readonly ?string $content = null,
        private readonly array $parts = [],
    ) {}

    public function partId(): string
    {
        return $this->partId;
    }

    public function mimeType(): string
    {
        return $this->mimeType;
    }

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

    public function contentId(): ?string
    {
        return $this->contentId;
    }

    public function description(): ?string
    {
        return $this->description;
    }

    public function encoding(): ?string
    {
        return $this->encoding;
    }

    public function size(): ?int
    {
        return $this->size;
    }

    public function disposition(): ?string
    {
        return $this->disposition;
    }

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

    /**
     * @return list<string>
     */
    public function language(): array
    {
        return $this->language;
    }

    public function location(): ?string
    {
        return $this->location;
    }

    public function content(): ?string
    {
        return $this->content;
    }

    /**
     * @return list<MessagePart>
     */
    public function parts(): array
    {
        return $this->parts;
    }

    public function isMultipart(): bool
    {
        return str_starts_with($this->mimeType, 'multipart/');
    }

    /**
     * @param array<string, string> $sections
     */
    public function withInjectedSections(array $sections): self
    {
        if ($this->parts !== []) {
            $parts = [];
            foreach ($this->parts as $part) {
                $parts[] = $part->withInjectedSections($sections);
            }

            return new self(
                $this->partId,
                $this->mimeType,
                $this->parameters,
                $this->contentId,
                $this->description,
                $this->encoding,
                $this->size,
                $this->disposition,
                $this->dispositionParameters,
                $this->language,
                $this->location,
                $this->content,
                $parts,
            );
        }

        if (!str_starts_with($this->mimeType, 'text/')) {
            return $this;
        }

        if (!array_key_exists($this->partId, $sections)) {
            return $this;
        }

        return new self(
            $this->partId,
            $this->mimeType,
            $this->parameters,
            $this->contentId,
            $this->description,
            $this->encoding,
            $this->size,
            $this->disposition,
            $this->dispositionParameters,
            $this->language,
            $this->location,
            self::decodeContent($sections[$this->partId], $this->encoding, $this->parameters['charset'] ?? 'us-ascii'),
            [],
        );
    }

    public function toArray(): array
    {
        $data = [
            'partId' => $this->partId,
            'blobId' => $this->partId,
            'cId' => $this->contentId,
            'type' => $this->mimeType,
            'charset' => $this->parameters['charset'] ?? null,
            'name' => $this->parameters['name'] ?? $this->dispositionParameters['filename'] ?? null,
            'encoding' => $this->encoding,
            'size' => $this->size,
            'disposition' => $this->disposition,
            'language' => $this->language === [] ? null : implode(',', $this->language),
            'location' => $this->location,
            'content' => $this->content,
        ];

        $children = [];
        foreach ($this->parts as $part) {
            $children[] = $part->toArray();
        }

        $data['subParts'] = $children === [] ? null : $children;

        return array_filter($data, static fn (mixed $value): bool => $value !== null);
    }

    private static function decodeContent(string $content, ?string $encoding, string $charset): string
    {
        $decoded = match (strtolower($encoding ?? '7bit')) {
            'quoted-printable' => quoted_printable_decode($content),
            'base64' => base64_decode($content, true) ?: '',
            default => $content,
        };

        if ($charset === '' || in_array(strtolower($charset), ['utf-8', 'utf8'], true)) {
            return mb_convert_encoding($decoded, 'UTF-8', 'UTF-8');
        }

        try {
            $converted = mb_convert_encoding($decoded, 'UTF-8', $charset);
            if ($converted !== false) {
                return $converted;
            }
        } catch (\ValueError) {
        }

        $converted = @iconv($charset, 'UTF-8//TRANSLIT//IGNORE', $decoded);
        $decoded = $converted !== false ? $converted : $decoded;

        return mb_convert_encoding($decoded, 'UTF-8', 'UTF-8');
    }
}