using System.Text.Json;
using System.Text.Json.Serialization;

namespace JobTrackerApi.Models;

// A reviewed snapshot, never a live link to profile or CV settings.
public sealed class CoverLetterDocumentSettings
{
    public int SchemaVersion { get; set; } = 1;
    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
    public int? DesignVersion { get; set; }
    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
    public string? HeadingFont { get; set; }
    public string Language { get; set; } = "en";
    public string SenderName { get; set; } = "";
    public string SenderTitle { get; set; } = "";
    public string SenderEmail { get; set; } = "";
    public string SenderPhone { get; set; } = "";
    public string SenderLocation { get; set; } = "";
    public string Recipient { get; set; } = "";
    public string Subject { get; set; } = "";
    public string Date { get; set; } = "";
    public string ThemeId { get; set; } = "modern";
    public string? AccentColor { get; set; }
    public string? BodyFont { get; set; }
    public double? BaseFontSizePt { get; set; }
    public double? LineHeight { get; set; }
    public double? PageMarginMm { get; set; }
    public string PageSize { get; set; } = "a4";
    public int? SourceCvId { get; set; }
}

public static class CoverLetterDocumentSettingsJson
{
    private static readonly JsonSerializerOptions Options = new(JsonSerializerDefaults.Web);
    public static string Serialize(CoverLetterDocumentSettings? settings) => JsonSerializer.Serialize(Normalize(settings), Options);
    public static CoverLetterDocumentSettings Deserialize(string? json)
    {
        try { return Normalize(string.IsNullOrWhiteSpace(json) ? null : JsonSerializer.Deserialize<CoverLetterDocumentSettings>(json, Options)); }
        catch (JsonException) { return Normalize(null); }
    }

    public static CoverLetterDocumentSettings Normalize(CoverLetterDocumentSettings? value)
    {
        value ??= new();
        var theme = CvThemeCatalog.Resolve(value.ThemeId, value.DesignVersion);
        var style = CvVariantSettingsJson.Normalize(new()
        {
            AccentColor = value.AccentColor, BodyFont = value.BodyFont, HeadingFont = value.HeadingFont,
            BaseFontSizePt = value.BaseFontSizePt, LineHeight = value.LineHeight, PageMarginMm = value.PageMarginMm,
        });
        static string Text(string? text, int limit) => (text ?? "")[..Math.Min(text?.Length ?? 0, limit)];
        return new()
        {
            SchemaVersion = 1, ThemeId = theme.Id,
            DesignVersion = value.DesignVersion is 1 or 2 ? value.DesignVersion : null,
            HeadingFont = value.DesignVersion == 2 ? style.HeadingFont ?? theme.HeadingFont : null,
            Language = value.Language?.Trim().ToLowerInvariant() is "nb" or "nb-no" ? "nb-NO" : "en",
            SenderName = Text(value.SenderName, 300), SenderTitle = Text(value.SenderTitle, 300),
            SenderEmail = Text(value.SenderEmail, 300), SenderPhone = Text(value.SenderPhone, 100), SenderLocation = Text(value.SenderLocation, 300),
            Recipient = Text(value.Recipient, 2000), Subject = Text(value.Subject, 500), Date = Text(value.Date, 100),
            AccentColor = style.AccentColor ?? theme.Accent, BodyFont = style.BodyFont ?? theme.BodyFont,
            BaseFontSizePt = style.BaseFontSizePt ?? theme.BodySizePt, LineHeight = style.LineHeight ?? theme.LineHeight,
            PageMarginMm = style.PageMarginMm ?? theme.PageMarginMm,
            PageSize = string.Equals(value.PageSize, "letter", StringComparison.OrdinalIgnoreCase) ? "letter" : "a4",
            SourceCvId = value.SourceCvId is > 0 ? value.SourceCvId : null,
        };
    }
}