using System;
using System.Collections.Generic;
using System.Linq;
using OpenNest.Benchmark;
using OpenNest.CNC;
using OpenNest.Engine.Jobs;
using OpenNest.Engine.Jobs.Adapters;
using OpenNest.Geometry;

namespace OpenNest.Engine.Qwen38FlashNext.Tests;

/// <summary>
/// Starter acceptance tests. Every layout is checked by the same NestValidator the benchmark
/// scores with, so a passing test means the benchmark will accept the layout. They fail until
/// Solve() is implemented; add engine-specific tests alongside them.
/// </summary>
public class Qwen38FlashNextNestingEngineTests
{
    [Fact]
    public void HasPublicParameterlessConstructorForPluginDiscovery()
    {
        var engine = Activator.CreateInstance(typeof(Qwen38FlashNextNestingEngine));
        Assert.IsAssignableFrom<INestingEngine>(engine);
    }

    [Fact]
    public void RectanglesFitOnOneSheetWithSpacing()
    {
        var job = Job(new[] { Part("rect", Rectangle(10, 5), 12) }, new[] { Stock("sheet", 48, 96, spacing: 0.25) });

        var result = new Qwen38FlashNextNestingEngine().Solve(job);

        AssertValid(job, result);
        Assert.Equal(NestJobStatus.Complete, result.Status);
        Assert.Single(result.Plates);
        Assert.Equal(12, result.Plates[0].Placements.Count);
    }

    [Theory]
    [InlineData(1)]
    [InlineData(2)]
    [InlineData(3)]
    [InlineData(4)]
    public void MixedArcAndConcavePartsAreValidInEveryQuadrant(int quadrant)
    {
        var job = Job(
            new[]
            {
                Part("disc", Disc(3), 10),
                Part("ell", LShape(12, 8, 4), 10),
                Part("tri", Triangle(9, 6), 10),
            },
            new[] { Stock("sheet", 40, 60, spacing: 0.5, edge: new Spacing(0.5, 0.5, 0.5, 0.5), quadrant: quadrant) }
        );

        var result = new Qwen38FlashNextNestingEngine().Solve(job);

        AssertValid(job, result);
        Assert.Equal(NestJobStatus.Complete, result.Status);
    }

    [Fact]
    public void RotatedConcavePartsKeepSpacingAtFixedAngles()
    {
        // Regression: the per-orientation spacing inflation must live in the rotated
        // frame. L-shapes pinned to 90/270 degrees exercise exactly the orientations
        // where an unrotated inflation misrepresents the material and lets parts
        // rest closer than the spacing.
        var l = Part(
            "l90",
            LShape(12, 8, 4),
            8,
            RotationPolicy.Fixed(System.Math.PI / 2, allow180Equivalent: true)
        );
        var job = Job(new[] { l }, new[] { Stock("sheet", 40, 60, spacing: 0.5) });

        var result = new Qwen38FlashNextNestingEngine().Solve(job);

        AssertValid(job, result);
        Assert.Equal(NestJobStatus.Complete, result.Status);
    }

    [Fact]
    public void OverflowSpillsOntoAdditionalSheets()
    {
        var job = Job(new[] { Part("square", Rectangle(10, 10), 30) }, new[] { Stock("sheet", 25, 45, spacing: 0.25) });

        var result = new Qwen38FlashNextNestingEngine().Solve(job);

        AssertValid(job, result);
        Assert.Equal(NestJobStatus.Complete, result.Status);
        Assert.True(result.Plates.Count > 1);
    }

    [Fact]
    public void PartTooBigForAnySheetIsReportedUnplaced()
    {
        var job = Job(
            new[] { Part("huge", Rectangle(50, 50), 1), Part("small", Rectangle(5, 5), 4) },
            new[] { Stock("sheet", 20, 20, spacing: 0.25) }
        );

        var result = new Qwen38FlashNextNestingEngine().Solve(job);

        AssertValid(job, result);
        var huge = Assert.Single(result.Fulfillment, f => f.PartId == "huge");
        Assert.Equal(1, huge.Unplaced);
    }

    // ---- helpers -------------------------------------------------------------------------

    private static void AssertValid(NestJob job, NestJobResult result)
    {
        var materialized = NestResultMaterializer.Materialize(job, result);
        var runs = materialized.Nest.Plates.Select(plate => (Plate: plate, Parts: plate.Parts.ToList())).ToList();
        var requirements = job.Parts.ToDictionary<NestJobPart, Drawing, (string Name, int Quantity)>(
            p => materialized.DrawingsByPartId[p.Id],
            p => (p.Id, p.Quantity),
            ReferenceEqualityComparer.Instance
        );
        var validation = NestValidator.Validate(runs, requirements);
        NestValidator.ValidateAgainstJob(job, result, job.Parts.ToDictionary(p => p.Id, p => p.Id), validation);
        Assert.True(validation.Valid, string.Join(Environment.NewLine, validation.Violations));

        foreach (var f in result.Fulfillment)
            Assert.Equal(f.Requested, f.Placed + f.Unplaced);
    }

    private static NestJob Job(NestJobPart[] parts, NestPlateStock[] stock, NestJobOptions? options = null) =>
        new(parts, stock, options);

    private static NestJobPart Part(string id, Program program, int quantity, RotationPolicy? rotation = null) =>
        new(id, PartGeometrySnapshot.FromProgram(program), quantity, 0, rotation);

    /// <param name="width">Y extent.</param>
    /// <param name="length">X extent.</param>
    private static NestPlateStock Stock(
        string id,
        double width,
        double length,
        double spacing = 0,
        Spacing edge = default,
        int quadrant = 1,
        int? quantity = null
    ) => new(id, new Size(width, length), quantity, spacing, edge, quadrant);

    private static Program Polyline(params (double X, double Y)[] points)
    {
        var program = new Program();
        program.Codes.Add(new RapidMove(points[0].X, points[0].Y));
        foreach (var (x, y) in points.Skip(1))
            program.Codes.Add(new LinearMove(x, y));
        program.Codes.Add(new LinearMove(points[0].X, points[0].Y));
        return program;
    }

    private static Program Rectangle(double w, double h) => Polyline((0, 0), (w, 0), (w, h), (0, h));

    private static Program Triangle(double w, double h) => Polyline((0, 0), (w, 0), (w * 0.3, h));

    private static Program LShape(double w, double h, double t) => Polyline((0, 0), (w, 0), (w, t), (t, t), (t, h), (0, h));

    private static Program Disc(double r)
    {
        var program = new Program();
        program.Codes.Add(new RapidMove(r, 0));
        program.Codes.Add(new ArcMove(-r, 0, 0, 0, RotationType.CCW));
        program.Codes.Add(new ArcMove(r, 0, 0, 0, RotationType.CCW));
        return program;
    }
}