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

namespace XplorePlane.Tests.Generators
{
    /// <summary>
    /// FsCheck 自定义生成器：为配方相关模型定义 Arbitrary 生成器。
    /// 使用 Arb.Register&lt;RecipeGenerators&gt;() 注册。
    /// </summary>
    public class RecipeGenerators
    {
        // ── PipelineModel: class with settable properties ──

        public static Arbitrary<PipelineModel> PipelineModelArb()
        {
            var gen = from id in Arb.Default.Guid().Generator
                      from name in Arb.Default.NonEmptyString().Generator
                      from deviceId in Arb.Default.NonEmptyString().Generator
                      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 Arb.From(gen);
        }

        // ── RecipeStep: reuses StateGenerators for hardware states ──

        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 Arb.From(gen);
        }

        // ── InspectionRecipe: 0-10 steps with sequential StepIndex ──

        public static Arbitrary<InspectionRecipe> InspectionRecipeArb()
        {
            var gen = from id in Arb.Default.Guid().Generator
                      from name in Arb.Default.NonEmptyString().Generator
                      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 Arb.From(gen);
        }

        // ── RecipeExecutionState ──

        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 Arb.Default.NonEmptyString().Generator
                      select new RecipeExecutionState(currentStep, totalSteps, status, recipeName.Get);
            return Arb.From(gen);
        }

        // ── Helper: generate a list of steps with sequential StepIndex 0..n-1 ──

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

            return Gen.Sequence(
                Enumerable.Range(0, count).Select(i =>
                    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(i, motion, ray, detector, pipeline)
                )
            ).Select(steps => steps.ToList());
        }
    }
}