using System;
using FluidSim.Components;
using FluidSim.Utils;

namespace FluidSim.Core
{
    public static class Simulation
    {
        private static Solver solver;
        private static Volume0D volA, volB;
        private static Pipe1D pipe;
        private static Connection connA, connB;
        private static int stepCount;
        private static double time;
        private static double dt;

        public static void Initialize(int sampleRate)
        {
            dt = 1.0 / sampleRate;

            double V = 5.0 * Units.L;
            volA = new Volume0D(V, 2.0 * Units.atm, Units.Celsius(20), sampleRate);
            volB = new Volume0D(V, 1.0 * Units.atm, Units.Celsius(20), sampleRate);

            double length = 150 * Units.mm;
            double diameter = 25 * Units.mm;
            double area = Units.AreaFromDiameter(25, Units.mm);

            pipe = new Pipe1D(length, area, sampleRate);
            pipe.SetUniformState(volA.Density, 0.0, volA.Pressure);
            pipe.FrictionFactor = 0.02;

            // Connections with orifice area equal to pipe area (flange joint)
            connA = new Connection(volA.Port, pipe.PortA) { Area = area, DischargeCoefficient = 1.0, Gamma = 1.4 };
            connB = new Connection(pipe.PortB, volB.Port) { Area = area, DischargeCoefficient = 1.0, Gamma = 1.4 };

            solver = new Solver();
            solver.AddVolume(volA);
            solver.AddVolume(volB);
            solver.AddPipe(pipe);
            solver.AddConnection(connA);
            solver.AddConnection(connB);
        }

        public static float Process()
        {
            solver.Step();
            time += dt;
            stepCount++;
            Log();
            return 0f;
        }

        public static void Log()
        {
            bool logPipe = true;

            if ((stepCount <= 10 || (stepCount <= 1000 && stepCount % 100 == 0)) || stepCount % 1000 == 0 && stepCount < 10000)
            {
                // Summary line
                Console.WriteLine(
                    $"t = {time * 1e3:F3} ms  Step {stepCount:D4}: " +
                    $"PA = {volA.Pressure / 1e5:F6} bar, " +
                    $"PB = {volB.Pressure / 1e5:F6} bar, " +
                    $"FlowA = {pipe.PortA.MassFlowRate * 1e3:F2} g/s");

                // Per‑cell state
                if (logPipe && stepCount <= 1000)
                {
                    int n = pipe.GetCellCount();
                    for (int i = 0; i < n; i++)
                    {
                        double rho = pipe.GetCellDensity(i);
                        double p = pipe.GetCellPressure(i);
                        double u = pipe.GetCellVelocity(i);
                        Console.WriteLine(
                            $"  Cell {i,2}: ρ={rho,8:F4} kg/m³, p={p,10:F2} Pa, u={u,8:F3} m/s");
                    }
                }
            }
        }
    }
}