import gradio as gr

from ast_parser import Parser, EquationKind
from algorithm import solver

def process(input_equation):

    parser = Parser(input_equation)

    equations = tuple(parser)

    for equation in equations:
        if equation.kind == EquationKind.GEQ and equation.bound < 0.0:
            for variable, coefficient in equation.variables.items():
                equation.variables[variable] *= -1.0

            equation.bound *= -1.0
            equation.kind = EquationKind.LEQ

            continue

        if equation.kind == EquationKind.GEQ:
            raise ValueError("Equation kind must be either EQ or LEQ")
        if equation.bound < 0.0:
            raise ValueError("Equation bound must be non-negative")

    demand: dict[str, list[int]] = {}
    for i, equation in enumerate(equations):
        for variable, coefficient in equation.variables.items():
            if coefficient == 0.0:
                continue

            if variable not in demand:
                demand[variable] = []

            demand[variable].append(i)

    objective_variables = tuple(
        filter(lambda variable: len(demand[variable]) == 1, demand.keys())
    )

    objective_functions = tuple(
        filter(
            lambda function: function.kind == EquationKind.EQ,
            map(lambda variable: equations[demand[variable][0]], objective_variables),
        )
    )

    if len(objective_variables) != len(objective_functions):
        raise ValueError("Objective functions must be equalities")

    constraints = tuple(
        filter(
            lambda function: function not in objective_functions,
            equations,
        )
    )

    solver_instance  = solver.Solver(objective_functions, constraints)

    results = solver_instance.get_results()
    return results
    
description = "This app calculates optimum value using Simplex Method. Enter all equations, following each with a comma. The last equation should be without a comma. As an example 'Z = 5x_1 + 4x_2', '6x_1 + 4x_2 <= 24'"
examples = [["Z = 5x_1 + 4x_2,6x_1 + 4x_2 <= 24"]]
demo = gr.Interface(fn=process, inputs="text", outputs="text", title="Optimization Assignment",examples=examples,description=description)
    
demo.launch()