using System;
using System.Collections.Generic;
using System.Linq;
using FsCheck;
using FsCheck.Fluent;
using XplorePlane.Models;

namespace XplorePlane.Tests.Generators
{
    /// <summary>
    /// FsCheck 3.x 自定义生成器：为配方相关模型定义 Arbitrary 生成器。
    /// </summary>
    public class RecipeGenerators
    {
        public static Arbitrary<PipelineModel> PipelineModelArb()
        {
            var gen = from id in ArbMap.Default.GeneratorFor<Guid>()
                      from name in ArbMap.Default.GeneratorFor<NonEmptyString>()
                      from deviceId in ArbMap.Default.GeneratorFor<NonEmptyString>()
                      from ticks in Gen.Choose(0, int.MaxValue)
                      let createdAt = DateTime.MinValue.AddTicks((long)ticks * 10000)
                      let updatedAt = createdAt
                      select new PipelineModel
                      {
                          Id = id,
                          Name = name.Get,
                          DeviceId = deviceId.Get,
                          CreatedAt = createdAt,
                          UpdatedAt = updatedAt,
                          Nodes = new List<PipelineNodeModel>()
                      };
            return gen.ToArbitrary();
        }

        public static Arbitrary<RecipeStep> RecipeStepArb()
        {
            var gen = from stepIndex in Gen.Choose(0, 100)
                      from motion in StateGenerators.MotionStateArb().Generator
                      from ray in StateGenerators.RaySourceStateArb().Generator
                      from detector in StateGenerators.DetectorStateArb().Generator
                      from pipeline in PipelineModelArb().Generator
                      select new RecipeStep(stepIndex, motion, ray, detector, pipeline);
            return gen.ToArbitrary();
        }

        public static Arbitrary<InspectionRecipe> InspectionRecipeArb()
        {
            var gen = from id in ArbMap.Default.GeneratorFor<Guid>()
                      from name in ArbMap.Default.GeneratorFor<NonEmptyString>()
                      from ticks in Gen.Choose(0, int.MaxValue)
                      let createdAt = DateTime.MinValue.AddTicks((long)ticks * 10000)
                      let updatedAt = createdAt
                      from stepCount in Gen.Choose(0, 10)
                      from steps in GenSequentialSteps(stepCount)
                      select new InspectionRecipe(
                          id,
                          name.Get,
                          createdAt,
                          updatedAt,
                          steps.AsReadOnly());
            return gen.ToArbitrary();
        }

        public static Arbitrary<RecipeExecutionState> RecipeExecutionStateArb()
        {
            var gen = from totalSteps in Gen.Choose(0, 50)
                      from currentStep in Gen.Choose(0, Math.Max(totalSteps, 1) - 1)
                      from status in Gen.Elements(
                          RecipeExecutionStatus.Idle,
                          RecipeExecutionStatus.Running,
                          RecipeExecutionStatus.Paused,
                          RecipeExecutionStatus.Completed,
                          RecipeExecutionStatus.Error)
                      from recipeName in ArbMap.Default.GeneratorFor<NonEmptyString>()
                      select new RecipeExecutionState(currentStep, totalSteps, status, recipeName.Get);
            return gen.ToArbitrary();
        }

        private static Gen<List<RecipeStep>> GenSequentialSteps(int count)
        {
            if (count == 0)
                return Gen.Constant(new List<RecipeStep>());

            // Build list step by step using SelectMany chain
            Gen<List<RecipeStep>> result = Gen.Constant(new List<RecipeStep>());
            for (int i = 0; i < count; i++)
            {
                var idx = i;
                result = from list in result
                         from motion in StateGenerators.MotionStateArb().Generator
                         from ray in StateGenerators.RaySourceStateArb().Generator
                         from detector in StateGenerators.DetectorStateArb().Generator
                         from pipeline in PipelineModelArb().Generator
                         select new List<RecipeStep>(list)
                         {
                             new RecipeStep(idx, motion, ray, detector, pipeline)
                         };
            }
            return result;
        }
    }
}