using FinlyticNews.Entities;
using Microsoft.EntityFrameworkCore;

namespace FinlyticNews.Database;

/// <summary>
/// Entity Framework Core database context for the news microservice,
/// managing article sources, processed news, and matched assets.
/// </summary>
public class NewsDbContext : DbContext
{
    /// <summary>
    /// Initializes a new instance of the <see cref="NewsDbContext"/> class.
    /// </summary>
    /// <param name="options">The context configuration options.</param>
    public NewsDbContext(DbContextOptions<NewsDbContext> options) : base(options)
    {
    }

    /// <summary>
    /// Gets or sets the database set for configured article sources.
    /// </summary>
    public DbSet<ArticleSourceEntity> ArticleSources => Set<ArticleSourceEntity>();

    /// <summary>
    /// Gets or sets the database set for news articles.
    /// </summary>
    public DbSet<NewsArticleEntity> NewsArticles => Set<NewsArticleEntity>();

    /// <summary>
    /// Gets or sets the database set for matched assets.
    /// </summary>
    public DbSet<MatchedAssetEntity> MatchedAssets => Set<MatchedAssetEntity>();

    /// <summary>
    /// Gets or sets the database set for microservice configuration settings.
    /// </summary>
    public DbSet<NewsSettingsEntity> Settings => Set<NewsSettingsEntity>();

    /// <summary>
    /// Configures the model mapping, database constraints, and unique indices.
    /// </summary>
    /// <param name="modelBuilder">The builder being used to construct the database schema model.</param>
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);

        // Configure unique index on SourceUrl for deduplication check (idempotency)
        modelBuilder.Entity<NewsArticleEntity>()
            .HasIndex(a => a.SourceUrl)
            .IsUnique();

        // Performance indexes for news queries
        modelBuilder.Entity<NewsArticleEntity>()
            .HasIndex(a => new { a.PublishedAt, a.ScrapedAt });

        modelBuilder.Entity<NewsArticleEntity>()
            .HasIndex(a => a.Status);

        modelBuilder.Entity<MatchedAssetEntity>()
            .HasIndex(m => m.Isin);

        // Configure relationship between NewsArticle and MatchedAssets
        modelBuilder.Entity<MatchedAssetEntity>()
            .HasOne(m => m.NewsArticle)
            .WithMany(a => a.MatchedAssets)
            .HasForeignKey(m => m.NewsArticleId)
            .OnDelete(DeleteBehavior.Cascade);
    }
}