using System;
using System.Collections.Generic;
using System.Linq;
using Spectre.Console.Rendering;

namespace Spectre.Console
{
    /// <summary>
    /// Renders things in rows.
    /// </summary>
    public sealed class Rows : Renderable, IExpandable
    {
        private readonly List<IRenderable> _children;

        /// <inheritdoc/>
        public bool Expand { get; set; }

        /// <summary>
        /// Initializes a new instance of the <see cref="Rows"/> class.
        /// </summary>
        /// <param name="items">The items to render as rows.</param>
        public Rows(params IRenderable[] items)
            : this((IEnumerable<IRenderable>)items)
        {
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="Rows"/> class.
        /// </summary>
        /// <param name="children">The items to render as rows.</param>
        public Rows(IEnumerable<IRenderable> children)
        {
            _children = new List<IRenderable>(children ?? throw new ArgumentNullException(nameof(children)));
        }

        /// <inheritdoc/>
        protected override Measurement Measure(RenderContext context, int maxWidth)
        {
            if (Expand)
            {
                return new Measurement(maxWidth, maxWidth);
            }
            else
            {
                var measurements = _children.Select(c => c.Measure(context, maxWidth));
                return new Measurement(
                    measurements.Min(c => c.Min),
                    measurements.Min(c => c.Max));
            }
        }

        /// <inheritdoc/>
        protected override IEnumerable<Segment> Render(RenderContext context, int maxWidth)
        {
            var result = new List<Segment>();

            foreach (var child in _children)
            {
                var segments = child.Render(context, maxWidth);
                foreach (var (_, _, last, segment) in segments.Enumerate())
                {
                    result.Add(segment);

                    if (last)
                    {
                        if (!segment.IsLineBreak)
                        {
                            result.Add(Segment.LineBreak);
                        }
                    }
                }
            }

            return result;
        }
    }
}