using System.Collections.Generic;
using System.Linq;
using Questionable.Model;
using Questionable.Model.Questing;

namespace Questionable.Validation.Validators;

internal sealed class LandingZoneValidator : IQuestValidator
{
	public IEnumerable<ValidationIssue> Validate(Quest quest)
	{
		foreach (var stepInfo in quest.AllSteps().Where<(QuestSequence, int, QuestStep)>(delegate((QuestSequence Sequence, int StepId, QuestStep Step) x)
		{
			List<LandingZone> landingZones = x.Step.LandingZones;
			return landingZones != null && landingZones.Count > 0;
		}))
		{
			for (int z = 0; z < stepInfo.Item3.LandingZones.Count; z++)
			{
				LandingZone zone = stepInfo.Item3.LandingZones[z];
				if (zone.Vertices.Count < 3)
				{
					yield return new ValidationIssue
					{
						ElementId = quest.Id,
						Sequence = stepInfo.Item1.Sequence,
						Step = stepInfo.Item2,
						Type = EIssueType.InvalidLandingZone,
						Severity = EIssueSeverity.Error,
						Description = $"Landing zone {z} has fewer than 3 vertices"
					};
					continue;
				}
				if (!LandingZoneMath.IsConvex(zone.Vertices))
				{
					yield return new ValidationIssue
					{
						ElementId = quest.Id,
						Sequence = stepInfo.Item1.Sequence,
						Step = stepInfo.Item2,
						Type = EIssueType.InvalidLandingZone,
						Severity = EIssueSeverity.Error,
						Description = $"Landing zone {z} is not convex"
					};
				}
				if (LandingZoneMath.CalculatePolygonArea(zone.Vertices) < 0.01f)
				{
					yield return new ValidationIssue
					{
						ElementId = quest.Id,
						Sequence = stepInfo.Item1.Sequence,
						Step = stepInfo.Item2,
						Type = EIssueType.InvalidLandingZone,
						Severity = EIssueSeverity.Error,
						Description = $"Landing zone {z} has zero area (collinear vertices)"
					};
				}
			}
		}
	}
}