library/api/src/app/services/music.service.ts

/**
 * @copyright 2026 NHCarrigan
 * @license Naomi's Public License
 * @author Naomi Carrigan
 */

import { Music, MusicStatus, MusicType, CreateMusicDto, UpdateMusicDto } from "@library/shared-types";
import { prisma } from "../lib/prisma";
import {
  validateUrl,
  validateRating,
  validateStringLength,
  validateDataUrl,
  MAX_LENGTHS,
} from "../utils/validation";

export class MusicService {
  private prisma = prisma;

  constructor() {}

  /**
   * Validate music data for security.
   */
  private validateMusicData(data: CreateMusicDto | UpdateMusicDto): void {
    // Validate string lengths
    if (!validateStringLength(data.title, MAX_LENGTHS.TITLE)) {
      throw new Error(`Title must be ${MAX_LENGTHS.TITLE} characters or less.`);
    }
    if (!validateStringLength(data.artist, MAX_LENGTHS.AUTHOR)) {
      throw new Error(`Artist must be ${MAX_LENGTHS.AUTHOR} characters or less.`);
    }
    if (!validateStringLength(data.notes, MAX_LENGTHS.NOTES)) {
      throw new Error(`Notes must be ${MAX_LENGTHS.NOTES} characters or less.`);
    }
    if (!validateStringLength(data.coverArt, MAX_LENGTHS.URL)) {
      throw new Error(`Cover art URL must be ${MAX_LENGTHS.URL} characters or less.`);
    }

    // Validate rating
    if (data.rating !== undefined && !validateRating(data.rating)) {
      throw new Error("Rating must be an integer between 0 and 10.");
    }

    // Validate cover art URL
    if (data.coverArt) {
      if (data.coverArt.startsWith("data:")) {
        const sizeInBytes = data.coverArt.length * 0.75;
        if (sizeInBytes > MAX_LENGTHS.DATA_URL) {
          throw new Error("Cover image must be under 5MB.");
        }
        if (!validateDataUrl(data.coverArt)) {
          throw new Error("Invalid image data URL.");
        }
      } else {
        if (!validateStringLength(data.coverArt, MAX_LENGTHS.URL)) {
          throw new Error(`Cover image URL must be ${MAX_LENGTHS.URL} characters or less.`);
        }
        if (!validateUrl(data.coverArt)) {
          throw new Error("Invalid cover image URL. Only http and https URLs are allowed.");
        }
      }
    }

    // Validate tags
    if (data.tags) {
      for (const tag of data.tags) {
        if (!validateStringLength(tag, MAX_LENGTHS.TAGS)) {
          throw new Error(`Each tag must be ${MAX_LENGTHS.TAGS} characters or less.`);
        }
      }
    }

    // Validate link URLs
    if (data.links) {
      for (const link of data.links) {
        if (!validateUrl(link.url)) {
          throw new Error(`Invalid link URL: ${link.title}. Only http and https URLs are allowed.`);
        }
        if (!validateStringLength(link.title, MAX_LENGTHS.TITLE)) {
          throw new Error(`Link title must be ${MAX_LENGTHS.TITLE} characters or less.`);
        }
        if (!validateStringLength(link.url, MAX_LENGTHS.URL)) {
          throw new Error(`Link URL must be ${MAX_LENGTHS.URL} characters or less.`);
        }
      }
    }
  }

  /**
   * Get all music.
   */
  async getAllMusic(): Promise<Music[]> {
    const musicItems = await this.prisma.music.findMany({
      orderBy: { updatedAt: "desc" },
    });

    return musicItems.map((music) => ({
      ...music,
      type: music.type as unknown as MusicType,
      status: music.status as unknown as MusicStatus,
      dateAdded: music.dateAdded,
      dateStarted: music.dateStarted || undefined,
      dateCompleted: music.dateCompleted || undefined,
      dateFinished: music.dateFinished || undefined,
      tags: music.tags ?? [],
      links: music.links ?? [],
      createdAt: music.createdAt,
      updatedAt: music.updatedAt,
    }));
  }

  /**
   * Get music by ID.
   */
  async getMusicById(id: string): Promise<Music | null> {
    const music = await this.prisma.music.findUnique({
      where: { id },
    });

    if (!music) return null;

    return {
      ...music,
      type: music.type as unknown as MusicType,
      status: music.status as unknown as MusicStatus,
      dateAdded: music.dateAdded,
      dateStarted: music.dateStarted || undefined,
      dateCompleted: music.dateCompleted || undefined,
      dateFinished: music.dateFinished || undefined,
      tags: music.tags ?? [],
      links: music.links ?? [],
      createdAt: music.createdAt,
      updatedAt: music.updatedAt,
    };
  }

  /**
   * Create new music.
   */
  async createMusic(data: CreateMusicDto): Promise<Music> {
    // Validate input
    this.validateMusicData(data);

    const music = await this.prisma.music.create({
      data: {
        ...data,
        type: data.type.toUpperCase() as any,
        status: data.status.toUpperCase() as any,
      },
    });

    return {
      ...music,
      type: music.type as unknown as MusicType,
      status: music.status as unknown as MusicStatus,
      dateAdded: music.dateAdded,
      dateStarted: music.dateStarted || undefined,
      dateCompleted: music.dateCompleted || undefined,
      dateFinished: music.dateFinished || undefined,
      tags: music.tags ?? [],
      links: music.links ?? [],
      createdAt: music.createdAt,
      updatedAt: music.updatedAt,
    };
  }

  /**
   * Update music by ID.
   */
  async updateMusic(id: string, data: UpdateMusicDto): Promise<Music> {
    // Validate input
    this.validateMusicData(data);

    const updateData = { ...data };
    if (updateData.type) {
      updateData.type = updateData.type.toUpperCase() as any;
    }
    if (updateData.status) {
      updateData.status = updateData.status.toUpperCase() as any;
    }

    const music = await this.prisma.music.update({
      where: { id },
      data: updateData,
    });

    return {
      ...music,
      type: music.type as unknown as MusicType,
      status: music.status as unknown as MusicStatus,
      dateAdded: music.dateAdded,
      dateStarted: music.dateStarted || undefined,
      dateCompleted: music.dateCompleted || undefined,
      dateFinished: music.dateFinished || undefined,
      tags: music.tags ?? [],
      links: music.links ?? [],
      createdAt: music.createdAt,
      updatedAt: music.updatedAt,
    };
  }

  /**
   * Delete music by ID.
   */
  async deleteMusic(id: string): Promise<void> {
    await this.prisma.music.delete({
      where: { id },
    });
  }
}