# Simulation.jl
# API of Simulation class, that holds all information regarding a
# specific simulation run like its timestep, number of iterations and output
# options. Simulation object also holds a predefined Grid and Boundary object.
# Translated from C++'s Simulation.hpp.

struct Simulation{T} <: AbstractSimulation{T}
    grid::Grid{T}
    bc::Boundary{T}
    approach::APPROACH

    iterations::Int
    timestep::T

    consoleOutput::CONSOLE_OUTPUT
    csvOutput::CSV_OUTPUT

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

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

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

        if simulation.approach == BTCS
            runBTCS(simulation.grid, simulation.bc, simulation.timestep, simulation.iterations, simulationStepCallback)
        elseif simulation.approach == FTCS
            timestep, iterations = adjustTimestep(simulation.grid, simulation.approach, simulation.timestep, simulation.iterations, simulation.consoleOutput >= CONSOLE_OUTPUT_VERBOSE)
            runFTCS(simulation.grid, simulation.bc, timestep, iterations, simulationStepCallback)
        else
            error("Undefined approach!")
        end

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

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

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

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

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

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

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