/// @file
/// Command line option processing for solid mechanics example using PETSc

#include "../include/cl-options.h"

// -----------------------------------------------------------------------------
// Process command line options
// -----------------------------------------------------------------------------
// Process general command line options
PetscErrorCode ProcessCommandLineOptions(MPI_Comm comm, AppCtx app_ctx) {
  PetscErrorCode ierr;
  PetscBool ceed_flag = PETSC_FALSE;

  PetscFunctionBeginUser;

  ierr = PetscOptionsBegin(comm, NULL,
                           "Elasticity / Hyperelasticity in PETSc with libCEED",
                           NULL); CHKERRQ(ierr);

  ierr = PetscOptionsString("-ceed", "CEED resource specifier",
                            NULL, app_ctx->ceed_resource, app_ctx->ceed_resource,
                            sizeof(app_ctx->ceed_resource), &ceed_flag);
  CHKERRQ(ierr);

  ierr = PetscStrncpy(app_ctx->output_dir, ".", 2);
  CHKERRQ(ierr); // Default - current directory
  ierr = PetscOptionsString("-output_dir", "Output directory",
                            NULL, app_ctx->output_dir, app_ctx->output_dir,
                            sizeof(app_ctx->output_dir), NULL); CHKERRQ(ierr);

  app_ctx->degree         = 3;
  ierr = PetscOptionsInt("-degree", "Polynomial degree of tensor product basis",
                         NULL, app_ctx->degree, &app_ctx->degree, NULL);
  CHKERRQ(ierr);

  app_ctx->q_extra         = 0;
  ierr = PetscOptionsInt("-qextra", "Number of extra quadrature points",
                         NULL, app_ctx->q_extra, &app_ctx->q_extra, NULL);
  CHKERRQ(ierr);

  ierr = PetscOptionsString("-mesh", "Read mesh from file", NULL,
                            app_ctx->mesh_file, app_ctx->mesh_file,
                            sizeof(app_ctx->mesh_file), NULL); CHKERRQ(ierr);

  app_ctx->problem_choice  = ELAS_LINEAR;       // Default - Linear Elasticity
  ierr = PetscOptionsEnum("-problem",
                          "Solves Elasticity & Hyperelasticity Problems",
                          NULL, problemTypes, (PetscEnum)app_ctx->problem_choice,
                          (PetscEnum *)&app_ctx->problem_choice, NULL);
  CHKERRQ(ierr);
  app_ctx->name = problemTypes[app_ctx->problem_choice];
  app_ctx->name_for_disp = problemTypesForDisp[app_ctx->problem_choice];

  app_ctx->num_increments = app_ctx->problem_choice == ELAS_LINEAR ? 1 : 10;
  ierr = PetscOptionsInt("-num_steps", "Number of pseudo-time steps",
                         NULL, app_ctx->num_increments, &app_ctx->num_increments,
                         NULL); CHKERRQ(ierr);

  app_ctx->forcing_choice  = FORCE_NONE;     // Default - no forcing term
  ierr = PetscOptionsEnum("-forcing", "Set forcing function option", NULL,
                          forcing_types, (PetscEnum)app_ctx->forcing_choice,
                          (PetscEnum *)&app_ctx->forcing_choice, NULL);
  CHKERRQ(ierr);

  PetscInt max_n = 3;
  app_ctx->forcing_vector[0] = 0;
  app_ctx->forcing_vector[1] = -1;
  app_ctx->forcing_vector[2] = 0;
  ierr = PetscOptionsScalarArray("-forcing_vec",
                                 "Direction to apply constant force", NULL,
                                 app_ctx->forcing_vector, &max_n, NULL);
  CHKERRQ(ierr);

  if ((app_ctx->problem_choice == ELAS_FSInitial_NH1 ||
       app_ctx->problem_choice == ELAS_FSInitial_NH2 ||
       app_ctx->problem_choice == ELAS_FSCurrent_NH1 ||
       app_ctx->problem_choice == ELAS_FSCurrent_NH2 ||
       app_ctx->problem_choice == ELAS_FSInitial_MR1) &&
      app_ctx->forcing_choice == FORCE_CONST)
    SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP,
            "Cannot use constant forcing and finite strain formulation. "
            "Constant forcing in reference frame currently unavaliable.");

  // Dirichlet boundary conditions
  app_ctx->bc_clamp_count = 16;
  ierr = PetscOptionsIntArray("-bc_clamp",
                              "Face IDs to apply incremental Dirichlet BC",
                              NULL, app_ctx->bc_clamp_faces, &app_ctx->bc_clamp_count,
                              NULL); CHKERRQ(ierr);
  // Set vector for each clamped BC
  for (PetscInt i = 0; i < app_ctx->bc_clamp_count; i++) {
    // Translation vector
    char option_name[25];
    const size_t nclamp_params = sizeof(app_ctx->bc_clamp_max[0])/sizeof(
                                   app_ctx->bc_clamp_max[0][0]);
    for (PetscInt j = 0; j < nclamp_params; j++)
      app_ctx->bc_clamp_max[i][j] = 0.;

    snprintf(option_name, sizeof option_name, "-bc_clamp_%d_translate",
             app_ctx->bc_clamp_faces[i]);
    max_n = 3;
    ierr = PetscOptionsScalarArray(option_name,
                                   "Vector to translate clamped end by", NULL,
                                   app_ctx->bc_clamp_max[i], &max_n, NULL);
    CHKERRQ(ierr);

    // Rotation vector
    max_n = 5;
    snprintf(option_name, sizeof option_name, "-bc_clamp_%d_rotate",
             app_ctx->bc_clamp_faces[i]);
    ierr = PetscOptionsScalarArray(option_name,
                                   "Vector with axis of rotation and rotation, in radians",
                                   NULL, &app_ctx->bc_clamp_max[i][3], &max_n, NULL);
    CHKERRQ(ierr);

    // Normalize
    PetscScalar norm = sqrt(app_ctx->bc_clamp_max[i][3]*app_ctx->bc_clamp_max[i][3]
                            + app_ctx->bc_clamp_max[i][4]*app_ctx->bc_clamp_max[i][4]
                            + app_ctx->bc_clamp_max[i][5]*app_ctx->bc_clamp_max[i][5]);
    if (fabs(norm) < 1e-16)
      norm = 1;
    for (PetscInt j = 0; j < 3; j++)
      app_ctx->bc_clamp_max[i][3 + j] /= norm;
  }

  // Neumann boundary conditions
  app_ctx->bc_traction_count = 16;
  ierr = PetscOptionsIntArray("-bc_traction",
                              "Face IDs to apply traction (Neumann) BC",
                              NULL, app_ctx->bc_traction_faces,
                              &app_ctx->bc_traction_count, NULL); CHKERRQ(ierr);
  // Set vector for each traction BC
  for (PetscInt i = 0; i < app_ctx->bc_traction_count; i++) {
    // Translation vector
    char option_name[25];
    for (PetscInt j = 0; j < 3; j++)
      app_ctx->bc_traction_vector[i][j] = 0.;

    snprintf(option_name, sizeof option_name, "-bc_traction_%d",
             app_ctx->bc_traction_faces[i]);
    max_n = 3;
    PetscBool set = false;
    ierr = PetscOptionsScalarArray(option_name,
                                   "Traction vector for constrained face", NULL,
                                   app_ctx->bc_traction_vector[i], &max_n, &set);
    CHKERRQ(ierr);

    if (!set)
      SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP,
              "Traction vector must be set for all traction boundary conditions.");
  }

  app_ctx->multigrid_choice = MULTIGRID_LOGARITHMIC;
  ierr = PetscOptionsEnum("-multigrid", "Set multigrid type option", NULL,
                          multigrid_types, (PetscEnum)app_ctx->multigrid_choice,
                          (PetscEnum *)&app_ctx->multigrid_choice, NULL);
  CHKERRQ(ierr);

  app_ctx->test_mode = PETSC_FALSE;
  ierr = PetscOptionsBool("-test",
                          "Testing mode (do not print unless error is large)",
                          NULL, app_ctx->test_mode, &(app_ctx->test_mode), NULL);
  CHKERRQ(ierr);

  app_ctx->expect_final_strain = -1.;
  ierr = PetscOptionsReal("-expect_final_strain_energy",
                          "Expect final strain energy close to this value.",
                          NULL, app_ctx->expect_final_strain, &app_ctx->expect_final_strain, NULL);
  CHKERRQ(ierr);

  app_ctx->test_tol = 1e-8;
  ierr = PetscOptionsReal("-expect_final_state_rtol",
                          "Relative tolerance for final strain energy test",
                          NULL, app_ctx->test_tol, &app_ctx->test_tol, NULL);
  CHKERRQ(ierr);

  app_ctx->view_soln = PETSC_FALSE;
  ierr = PetscOptionsBool("-view_soln", "Write out solution vector for viewing",
                          NULL, app_ctx->view_soln, &(app_ctx->view_soln), NULL);
  CHKERRQ(ierr);

  app_ctx->view_final_soln = PETSC_FALSE;
  ierr = PetscOptionsBool("-view_final_soln",
                          "Write out final solution vector for viewing",
                          NULL, app_ctx->view_final_soln, &(app_ctx->view_final_soln),
                          NULL); CHKERRQ(ierr);
  CHKERRQ(ierr);

  PetscBool set;
  char energy_viewer_filename[PETSC_MAX_PATH_LEN] = "";
  ierr = PetscOptionsString("-strain_energy_monitor",
                            "Print out current strain energy at every load increment",
                            NULL, energy_viewer_filename,
                            energy_viewer_filename, sizeof(energy_viewer_filename),
                            &set); CHKERRQ(ierr);
  if (set) {
    ierr = PetscViewerASCIIOpen(comm, energy_viewer_filename,
                                &app_ctx->energy_viewer); CHKERRQ(ierr);
    ierr = PetscViewerASCIIPrintf(app_ctx->energy_viewer, "increment,energy\n");
    CHKERRQ(ierr);
    // Initial configuration is base energy state; this may not be true if we extend in the future to
    // initially loaded configurations (because a truly at-rest initial state may not be realizable).
    ierr = PetscViewerASCIIPrintf(app_ctx->energy_viewer, "%f,%e\n", 0., 0.);
    CHKERRQ(ierr);
  }
  ierr = PetscOptionsEnd(); CHKERRQ(ierr); // End of setting AppCtx

  // Check for all required values set
  if (app_ctx->test_mode) {
    if (app_ctx->forcing_choice == FORCE_NONE && !app_ctx->bc_clamp_count)
      app_ctx->forcing_choice = FORCE_MMS;
  }
  if (!app_ctx->bc_clamp_count && app_ctx->forcing_choice != FORCE_MMS) {
    SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "-boundary options needed");
  }

  // Provide default ceed resource if not specified
  if (!ceed_flag) {
    const char *ceed_resource = "/cpu/self";
    strncpy(app_ctx->ceed_resource, ceed_resource, 10);
  }

  // Determine number of levels
  switch (app_ctx->multigrid_choice) {
  case MULTIGRID_LOGARITHMIC:
    app_ctx->num_levels = ceil(log(app_ctx->degree)/log(2)) + 1;
    break;
  case MULTIGRID_UNIFORM:
    app_ctx->num_levels = app_ctx->degree;
    break;
  case MULTIGRID_NONE:
    app_ctx->num_levels = 1;
    break;
  }

  // Populate array of degrees for each level for multigrid
  ierr = PetscMalloc1(app_ctx->num_levels, &(app_ctx->level_degrees));
  CHKERRQ(ierr);

  switch (app_ctx->multigrid_choice) {
  case MULTIGRID_LOGARITHMIC:
    for (int i = 0; i < app_ctx->num_levels-1; i++)
      app_ctx->level_degrees[i] = pow(2,i);
    app_ctx->level_degrees[app_ctx->num_levels-1] = app_ctx->degree;
    break;
  case MULTIGRID_UNIFORM:
    for (int i = 0; i < app_ctx->num_levels; i++)
      app_ctx->level_degrees[i] = i + 1;
    break;
  case MULTIGRID_NONE:
    app_ctx->level_degrees[0] = app_ctx->degree;
    break;
  }

  PetscFunctionReturn(0);
};