#include "fesa/loads/concentrated_nodal_load.h"

#include <cmath>
#include <stdexcept>
#include <string>
#include <utility>
#include <vector>

#include "fesa/fem/dof_manager.h"
#include "fesa/model/domain.h"

namespace fesa {
namespace {

constexpr std::size_t kDofsPerNode = 6U;

Status LoadFailure(const std::string& code, const SourceLocation& location,
                   const std::string& identity, const std::string& message) {
  return Status::Failure(
      FailureCategory::kModel,
      {{Severity::kError, code, location, "CLOAD", identity, message}});
}

}  // namespace

ConcentratedNodalLoad::ConcentratedNodalLoad(
    SourceTargetQuery target, std::array<double, 6> global_components,
    const std::size_t source_order)
    : target_{std::move(target)},
      global_components_{global_components},
      source_order_{source_order} {}

ConcentratedNodalLoad::ConcentratedNodalLoad(
    SourceTargetQuery target, const int source_dof, const double magnitude,
    const std::size_t source_order, SourceLocation location,
    std::optional<EntityIndex> amplitude_index, std::string amplitude_name_raw,
    SourceLocation amplitude_location)
    : target_{std::move(target)},
      source_order_{source_order},
      location_{std::move(location)},
      source_dof_{source_dof},
      amplitude_index_{amplitude_index},
      amplitude_name_raw_{std::move(amplitude_name_raw)},
      amplitude_location_{std::move(amplitude_location)} {
  if (source_dof >= 1 && source_dof <= static_cast<int>(kDofsPerNode)) {
    global_components_[static_cast<std::size_t>(source_dof - 1)] = magnitude;
  }
}

Result<std::vector<LoadContribution>>
ConcentratedNodalLoad::ComputeContributions(const LoadContext& context) const {
  const std::string& identity = target_.target_name_or_label;
  const std::size_t components = context.dof_manager.ComponentsPerNode();
  if (context.dof_manager.Profile() == DofProfile::kThermal ||
      (source_dof_ != 0 && source_dof_ > static_cast<int>(components))) {
    return Result<std::vector<LoadContribution>>::Failure(LoadFailure(
        "invalid-load-dof", location_, identity,
        "The source load component is inactive for this physical profile."));
  }
  for (std::size_t component = components; component < kDofsPerNode;
       ++component) {
    if (global_components_[component] != 0.0) {
      return Result<std::vector<LoadContribution>>::Failure(
          LoadFailure("invalid-load-dof", location_, identity,
                      "A Solid load cannot contain rotational components."));
    }
  }
  double amplitude = 1.0;
  if (amplitude_index_) {
    if (!context.domain.IsSolid() || context.domain.Dynamic() == nullptr ||
        *amplitude_index_ >= context.domain.Amplitudes().size() ||
        !std::isfinite(context.step_time) || context.step_time < 0.0) {
      return Result<std::vector<LoadContribution>>::Failure(
          LoadFailure("invalid-load-amplitude", location_, identity,
                      "Amplitude requires a valid Solid dynamic endpoint."));
    }
    amplitude = context.domain.Amplitudes()[*amplitude_index_].Evaluate(
        context.step_time);
  }
  if (source_dof_ != 0 &&
      (source_dof_ < 1 || source_dof_ > static_cast<int>(kDofsPerNode))) {
    return Result<std::vector<LoadContribution>>::Failure(LoadFailure(
        "invalid-load-dof", location_, identity,
        "A nodal load component must be in the range 1 through 6."));
  }
  for (const double component : global_components_) {
    if (!std::isfinite(component)) {
      return Result<std::vector<LoadContribution>>::Failure(
          LoadFailure("nonfinite-load-value", location_, identity,
                      "A nodal load magnitude must be finite."));
    }
  }
  if (target_.entity_kind != SourceEntityKind::kNode) {
    return Result<std::vector<LoadContribution>>::Failure(
        LoadFailure("invalid-load-target", location_, identity,
                    "A concentrated nodal load requires a node target."));
  }

  auto resolved = context.target_resolver.Resolve(target_);
  if (!resolved.HasValue()) {
    return Result<std::vector<LoadContribution>>::Failure(LoadFailure(
        "invalid-load-target", location_, identity,
        "The load target must resolve unambiguously to one node or one "
        "expanded node set."));
  }

  std::vector<unsigned char> seen(context.domain.Nodes().size(), 0U);
  std::vector<LoadContribution> contributions;
  contributions.reserve(resolved.Value().size() * components);
  for (const auto& target : resolved.Value()) {
    const EntityIndex node = target.entity_index;
    if (node >= context.domain.Nodes().size() || seen[node] != 0U) {
      return Result<std::vector<LoadContribution>>::Failure(LoadFailure(
          "invalid-load-target", location_, identity,
          "The expanded node set must contain unique in-range stable node "
          "identities."));
    }
    seen[node] = 1U;
    for (std::size_t component = 0U; component < components; ++component) {
      const double value = global_components_[component] * amplitude;
      if (!std::isfinite(value)) {
        return Result<std::vector<LoadContribution>>::Failure(
            LoadFailure("nonfinite-load-value", location_, identity,
                        "Sampled load magnitude must remain finite."));
      }
      try {
        contributions.push_back(
            {source_order_,
             context.dof_manager.FullDof(node,
                                         static_cast<DofComponent>(component)),
             value});
      } catch (const std::out_of_range&) {
        return Result<std::vector<LoadContribution>>::Failure(LoadFailure(
            "invalid-load-target", location_, identity,
            "The resolved load target must have all six full DOFs."));
      }
    }
  }
  return Result<std::vector<LoadContribution>>::Success(
      std::move(contributions));
}

const SourceTargetQuery& ConcentratedNodalLoad::Target() const noexcept {
  return target_;
}

const std::array<double, 6>& ConcentratedNodalLoad::GlobalComponents()
    const noexcept {
  return global_components_;
}

std::size_t ConcentratedNodalLoad::SourceOrder() const noexcept {
  return source_order_;
}

const SourceLocation& ConcentratedNodalLoad::Location() const noexcept {
  return location_;
}

}  // namespace fesa