using System.IO.Abstractions;
using ErsatzTV.Core;
using ErsatzTV.Core.Domain;
using ErsatzTV.Core.Graphics;
using ErsatzTV.Infrastructure.Data;
using Microsoft.EntityFrameworkCore;

namespace ErsatzTV.Infrastructure.Streaming.Graphics;

public static class GraphicsElementSeeder
{
    private const string OnNowNextYaml =
        """
        name: On Now / Next
        epg_entries: 2
        location: BottomLeft
        horizontal_margin_percent: 4
        vertical_margin_percent: 8
        width_percent: 42
        text_fit: Wrap
        text_align: Left
        z_index: 100
        # transparent until 4s in, fade in 1s, hold 6s, fade out 1s
        opacity_expression: "LinearFadeDuration(content_seconds, 4, 1, 6)"
        base_style: now
        styles:
          - name: now
            font_family: "Noto Sans"
            font_size: 30
            font_weight: 700
            text_color: "#FFFFFF"
            halo_color: "#000000"
            halo_width: 2
          - name: sub
            font_family: "Noto Sans"
            font_size: 22
            font_weight: 400
            text_color: "#DDDDDD"
            halo_color: "#000000"
            halo_width: 2
          - name: next
            font_family: "Noto Sans"
            font_size: 22
            font_weight: 400
            text_color: "#DDDDDD"
            halo_color: "#000000"
            halo_width: 2
        text: |
          [now]NOW  {{ Epg[0].Title }}[/now]
          {{ if Epg[0].SubTitle }}[sub]{{ Epg[0].SubTitle }}[/sub]{{ end }}
          {{ if (array.size Epg) > 1 }}[next]NEXT  {{ Epg[1].Title }}[/next]{{ end }}
        """;

    public static async Task SeedOnNowNext(TvContext context, IFileSystem fileSystem, CancellationToken cancellationToken)
    {
        string seededKey = ConfigElementKey.GraphicsOnNowNextSeeded.Key;
        bool alreadySeeded = await context.ConfigElements.AnyAsync(c => c.Key == seededKey, cancellationToken);
        if (alreadySeeded)
        {
            return;
        }

        string folder = FileSystemLayout.GraphicsElementsTextTemplatesFolder;
        string target = fileSystem.Path.Combine(folder, GraphicsElementDefaults.OnNowNextFileName);

        if (!fileSystem.Directory.Exists(folder))
        {
            fileSystem.Directory.CreateDirectory(folder);
        }

        // Adopt an operator's existing file untouched; only write when absent.
        if (!fileSystem.File.Exists(target))
        {
            await fileSystem.File.WriteAllTextAsync(target, OnNowNextYaml, cancellationToken);
        }

        await context.ConfigElements.AddAsync(
            new ConfigElement { Key = seededKey, Value = "true" },
            cancellationToken);
        await context.SaveChangesAsync(cancellationToken);
    }
}