using Printf

include("Grid.jl")
include("Boundary.jl")
include("Core/BTCS.jl")

@enum APPROACH BTCS
@enum SOLVER EIGEN_LU_SOLVER
@enum CONSOLE_OUTPUT CONSOLE_OUTPUT_OFF CONSOLE_OUTPUT_ON CONSOLE_OUTPUT_VERBOSE
@enum CSV_OUTPUT CSV_OUTPUT_OFF CSV_OUTPUT_ON CSV_OUTPUT_VERBOSE CSV_OUTPUT_XTREME

# Create the Simulation class
struct Simulation{T,approach,solver}
    grid::Grid{T}
    bc::Boundary{T}
    approach::APPROACH
    solver::SOLVER

    iterations::Int
    timestep::T

    consoleOutput::CONSOLE_OUTPUT
    csvOutput::CSV_OUTPUT

    function Simulation(grid::Grid{T}, bc::Boundary{T}, approach::APPROACH=BTCS,
        solver::SOLVER=EIGEN_LU_SOLVER, iterations::Int=1, timestep::T=0.1,
        consoleOutput::CONSOLE_OUTPUT=CONSOLE_OUTPUT_OFF, csvOutput::CSV_OUTPUT=CSV_OUTPUT_OFF) where {T}
        new{T,APPROACH,SOLVER}(grid, bc, approach, solver, iterations, timestep, consoleOutput, csvOutput)
    end

end

function createCSVfile(simulation::Simulation{T,approach,solver})::IOStream where {T,approach,solver}
    appendIdent = 0
    approachString = (simulation.approach == BTCS) ? "BTCS" : "UNKNOWN"  # Add other approaches as needed
    row = simulation.grid.rows
    col = simulation.grid.cols
    numIterations = simulation.iterations
    filename = string(approachString, "_", row, "_", col, "_", numIterations, ".csv")

    while isfile(filename)
        appendIdent += 1
        filename = string(approachString, "_", row, "_", col, "_", numIterations, "-", appendIdent, ".csv")
    end

    # Write boundary conditions if required
    if simulation.csvOutput == CSV_OUTPUT_XTREME
        open(filename, "w") do file
            writeBoundarySideValues(file, simulation.bc, LEFT)
            writeBoundarySideValues(file, simulation.bc, RIGHT)

            if simulation.grid.dim == 2
                writeBoundarySideValues(file, simulation.bc, TOP)
                writeBoundarySideValues(file, simulation.bc, BOTTOM)
            end

            write(file, "\n\n")
        end
    end

    file = open(filename, "a")
    return file
end

function writeBoundarySideValues(file, bc::Boundary{T}, side) where {T}
    values::Vector{BoundaryElement} = getBoundarySide(bc, side)
    formatted_values = join(map(getValue, values), " ")
    write(file, formatted_values, "\n")
end

function printConcentrationsCSV(simulation::Simulation{T,approach,solver}, file::IOStream) where {T,approach,solver}
    concentrations = simulation.grid.concentrations[]

    for row in eachrow(concentrations)
        formatted_row = [Printf.@sprintf("%.6g", x) for x in row]  # Format each element like is done in the C++ version using Eigen3
        println(file, join(formatted_row, " "))
    end
    println(file)  # Add extra newlines for separation
    println(file)
end

function printConcentrations(simulation::Simulation{T,approach,solver}) where {T,approach,solver}
    println(simulation.grid.concentrations[])
end

function run(simulation::Simulation{T,approach,solver}) where {T,approach,solver}
    file = nothing
    try
        if simulation.csvOutput > CSV_OUTPUT_OFF
            file = createCSVfile(simulation)
        end

        function simulationStepCallback()
            if simulation.consoleOutput >= CONSOLE_OUTPUT_VERBOSE
                printConcentrations(simulation)
            end
            if simulation.csvOutput >= CSV_OUTPUT_VERBOSE
                printConcentrationsCSV(simulation, file)
            end
        end

        if simulation.approach == BTCS
            runBTCS(simulation.grid, simulation.bc, simulation.timestep, simulation.iterations, simulationStepCallback)
        else
            error("Undefined approach!")
        end

        if simulation.consoleOutput >= CONSOLE_OUTPUT_ON
            printConcentrations(simulation)
        end

        if simulation.csvOutput >= CSV_OUTPUT_ON
            printConcentrationsCSV(simulation, file)
        end

    finally
        if file !== nothing
            close(file)
        end
    end
end

function setTimestep(simulation::Simulation{T,approach,solver}, timestep::T) where {T,approach,solver}
    return Simulation(simulation.grid, simulation.bc, simulation.approach, simulation.solver, simulation.iterations, timestep, simulation.consoleOutput, simulation.csvOutput)
end

function setIterations(simulation::Simulation{T,approach,solver}, iterations::Int) where {T,approach,solver}
    return Simulation(simulation.grid, simulation.bc, simulation.approach, simulation.solver, iterations, simulation.timestep, simulation.consoleOutput, simulation.csvOutput)
end

function setOutputConsole(simulation::Simulation{T,approach,solver}, consoleOutput::CONSOLE_OUTPUT) where {T,approach,solver}
    return Simulation(simulation.grid, simulation.bc, simulation.approach, simulation.solver, simulation.iterations, simulation.timestep, consoleOutput, simulation.csvOutput)
end

function setOutputCSV(simulation::Simulation{T,approach,solver}, csvOutput::CSV_OUTPUT) where {T,approach,solver}
    return Simulation(simulation.grid, simulation.bc, simulation.approach, simulation.solver, simulation.iterations, simulation.timestep, simulation.consoleOutput, csvOutput)
end