// Copyright (c) 2011 - 2019 Ed Charbeneau
// License: MIT
// See https://github.com/EdCharbeneau

using System;
using System.Collections.Generic;

namespace Connected.Utilities;

public struct StyleBuilder
{
	private string stringBuffer;
	private string style;

	/// <summary>
	/// Creates a StyleBuilder used to define conditional in-line style used in a component. Call Build() to return the completed style as a string.
	/// </summary>
	/// <param name="prop"></param>
	/// <param name="value"></param>
	public static StyleBuilder Default(string prop, string value) => new(prop, value);

	/// <summary>
	/// Creates a StyleBuilder used to define conditional in-line style used in a component. Call Build() to return the completed style as a string.
	/// </summary>
	/// <param name="style"></param>
	public static StyleBuilder Default(string style) => Empty().AddStyle(style);

	/// <summary>
	/// Creates a StyleBuilder used to define conditional in-line style used in a component. Call Build() to return the completed style as a string.
	/// </summary>
	public static StyleBuilder Empty() => new();

	/// <summary>
	/// Creates a StyleBuilder used to define conditional in-line style used in a component. Call Build() to return the completed style as a string.
	/// </summary>
	/// <param name="prop"></param>
	/// <param name="value"></param>
	public StyleBuilder(string prop, string value) => stringBuffer = $"{prop}:{value};";
	public StyleBuilder(string style) : this() => this.style = style;
 
	/// <summary>
	/// Adds a conditional in-line style to the builder with space separator and closing semicolon.
	/// </summary>
	/// <param name="style"></param>
	public StyleBuilder AddStyle(string style) => !string.IsNullOrWhiteSpace(style) ? AddRaw($"{style};") : this;

	/// <summary>
	/// Adds a raw string to the builder that will be concatenated with the next style or value added to the builder.
	/// </summary>
	/// <param name="style"></param>
	/// <returns>StyleBuilder</returns>
	private StyleBuilder AddRaw(string style)
	{
		stringBuffer += style;
		return this;
	}

	/// <summary>
	/// Adds a conditional in-line style to the builder with space separator and closing semicolon..
	/// </summary>
	/// <param name="prop"></param>
	/// <param name="value">Style to add</param>
	/// <returns>StyleBuilder</returns>
	public StyleBuilder AddStyle(string prop, string value) => AddRaw($"{prop}:{value};");

	/// <summary>
	/// Adds a conditional in-line style to the builder with space separator and closing semicolon..
	/// </summary>
	/// <param name="prop"></param>
	/// <param name="value">Style to conditionally add.</param>
	/// <param name="when">Condition in which the style is added.</param>
	/// <returns>StyleBuilder</returns>
	public StyleBuilder AddStyle(string prop, string value, bool when = true) => when ? this.AddStyle(prop, value) : this;


	/// <summary>
	/// Adds a conditional in-line style to the builder with space separator and closing semicolon..
	/// </summary>
	/// <param name="prop"></param>
	/// <param name="value">Style to conditionally add.</param>
	/// <param name="when">Condition in which the style is added.</param>
	/// <returns></returns>
	public StyleBuilder AddStyle(string prop, Func<string> value, bool when = true) => when ? this.AddStyle(prop, value()) : this;

	/// <summary>
	/// Adds a conditional in-line style to the builder with space separator and closing semicolon..
	/// </summary>
	/// <param name="prop"></param>
	/// <param name="value">Style to conditionally add.</param>
	/// <param name="when">Condition in which the style is added.</param>
	/// <returns>StyleBuilder</returns>
	public StyleBuilder AddStyle(string prop, string value, Func<bool> when = null) => this.AddStyle(prop, value, when != null && when());

	/// <summary>
	/// Adds a conditional in-line style to the builder with space separator and closing semicolon..
	/// </summary>
	/// <param name="prop"></param>
	/// <param name="value">Style to conditionally add.</param>
	/// <param name="when">Condition in which the style is added.</param>
	/// <returns>StyleBuilder</returns>
	public StyleBuilder AddStyle(string prop, Func<string> value, Func<bool> when = null) => this.AddStyle(prop, value(), when != null && when());

	/// <summary>
	/// Adds a conditional nested StyleBuilder to the builder with separator and closing semicolon.
	/// </summary>
	/// <param name="builder">Style Builder to conditionally add.</param>
	/// <returns>StyleBuilder</returns>
	public StyleBuilder AddStyle(StyleBuilder builder) => this.AddRaw(builder.Build());

	/// <summary>
	/// Adds a conditional nested StyleBuilder to the builder with separator and closing semicolon.
	/// </summary>
	/// <param name="builder">Style Builder to conditionally add.</param>
	/// <param name="when">Condition in which the style is added.</param>
	/// <returns>StyleBuilder</returns>
	public StyleBuilder AddStyle(StyleBuilder builder, bool when = true) => when ? this.AddRaw(builder.Build()) : this;

	/// <summary>
	/// Adds a conditional in-line style to the builder with space separator and closing semicolon..
	/// </summary>
	/// <param name="builder">Style Builder to conditionally add.</param>
	/// <param name="when">Condition in which the styles are added.</param>
	/// <returns>StyleBuilder</returns>
	public StyleBuilder AddStyle(StyleBuilder builder, Func<bool> when = null) => this.AddStyle(builder, when != null && when());

	/// <summary>
	/// Adds a conditional in-line style to the builder with space separator and closing semicolon..
	/// A ValueBuilder action defines a complex set of values for the property.
	/// </summary>
	/// <param name="prop"></param>
	/// <param name="builder"></param>
	/// <param name="when"></param>
	public StyleBuilder AddStyle(string prop, Action<ValueBuilder> builder, bool when = true)
	{
		var values = new ValueBuilder();
		builder(values);
		return AddStyle(prop, values.ToString(), when && values.HasValue);
	}

	/// <summary>
	/// Adds a conditional in-line style when it exists in a dictionary to the builder with separator.
	/// Null safe operation.
	/// </summary>
	/// <param name="additionalAttributes">Additional Attribute splat parameters</param>
	/// <returns>StyleBuilder</returns>
	public StyleBuilder AddStyleFromAttributes(IReadOnlyDictionary<string, object> additionalAttributes) =>
		 additionalAttributes == null ? this :
		 additionalAttributes.TryGetValue("style", out var c) ? AddRaw(c.ToString()) : this;


	/// <summary>
	/// Finalize the completed Style as a string.
	/// </summary>
	/// <returns>string</returns>
	public string Build()
	{
		// String buffer finalization code
		return stringBuffer != null ? stringBuffer.Trim() : string.Empty;
	}

	// ToString should only and always call Build to finalize the rendered string.
	public override string ToString() => Build();
}
