// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

#include "toolchain/semantics/semantics_ir.h"

#include "common/check.h"
#include "toolchain/parser/parse_tree_node_location_translator.h"
#include "toolchain/semantics/semantics_builtin_kind.h"
#include "toolchain/semantics/semantics_node.h"
#include "toolchain/semantics/semantics_parse_tree_handler.h"

namespace Carbon {

auto SemanticsIR::MakeBuiltinIR() -> SemanticsIR {
  SemanticsIR semantics(/*builtin_ir=*/nullptr);
  semantics.nodes_.reserve(SemanticsBuiltinKind::ValidCount);

#define CARBON_SEMANTICS_BUILTIN_KIND(Name, Type, ...)     \
  semantics.nodes_.push_back(SemanticsNode::Builtin::Make( \
      SemanticsBuiltinKind::Name, SemanticsNodeId::Builtin##Type));
#include "toolchain/semantics/semantics_builtin_kind.def"

  CARBON_CHECK(semantics.node_blocks_.size() == 1)
      << "BuildBuiltins should only have the empty block, actual: "
      << semantics.node_blocks_.size();
  CARBON_CHECK(semantics.nodes_.size() == SemanticsBuiltinKind::ValidCount)
      << "BuildBuiltins should produce " << SemanticsBuiltinKind::ValidCount
      << " nodes, actual: " << semantics.nodes_.size();
  return semantics;
}

auto SemanticsIR::MakeFromParseTree(const SemanticsIR& builtin_ir,
                                    const TokenizedBuffer& tokens,
                                    const ParseTree& parse_tree,
                                    DiagnosticConsumer& consumer,
                                    llvm::raw_ostream* vlog_stream)
    -> SemanticsIR {
  SemanticsIR semantics(&builtin_ir);

  // Copy builtins over.
  semantics.nodes_.resize_for_overwrite(SemanticsBuiltinKind::ValidCount);
  static constexpr auto BuiltinIR = SemanticsCrossReferenceIRId(0);
  for (int i = 0; i < SemanticsBuiltinKind::ValidCount; ++i) {
    // We can reuse the type node ID because the offsets of cross-references
    // will be the same in this IR.
    auto type = builtin_ir.nodes_[i].type_id();
    semantics.nodes_[i] = SemanticsNode::CrossReference::Make(
        type, BuiltinIR, SemanticsNodeId(i));
  }

  ParseTreeNodeLocationTranslator translator(&tokens, &parse_tree);
  ErrorTrackingDiagnosticConsumer err_tracker(consumer);
  DiagnosticEmitter<ParseTree::Node> emitter(translator, err_tracker);
  SemanticsParseTreeHandler(tokens, emitter, parse_tree, semantics, vlog_stream)
      .Build();
  semantics.has_errors_ = err_tracker.seen_error();
  return semantics;
}

static constexpr int Indent = 2;

template <typename T>
static auto PrintList(llvm::raw_ostream& out, llvm::StringLiteral name,
                      const llvm::SmallVector<T>& list) {
  out << name << ": [\n";
  for (const auto& element : list) {
    out.indent(Indent);
    out << element << ",\n";
  }
  out << "]\n";
}

auto SemanticsIR::Print(llvm::raw_ostream& out, bool include_builtins) const
    -> void {
  out << "cross_reference_irs_size: " << cross_reference_irs_.size() << "\n";

  PrintList(out, "calls", calls_);
  PrintList(out, "callables", callables_);
  PrintList(out, "integer_literals", integer_literals_);
  PrintList(out, "real_literals", real_literals_);
  PrintList(out, "strings", strings_);

  out << "nodes: [\n";
  for (int i = include_builtins ? 0 : SemanticsBuiltinKind::ValidCount;
       i < static_cast<int>(nodes_.size()); ++i) {
    const auto& element = nodes_[i];
    out.indent(Indent);
    out << element << ",\n";
  }
  out << "]\n";

  out << "node_blocks: [\n";
  for (const auto& node_block : node_blocks_) {
    out.indent(Indent);
    out << "[\n";

    for (const auto& node : node_block) {
      out.indent(2 * Indent);
      out << node << ",\n";
    }
    out.indent(Indent);
    out << "],\n";
  }
  out << "]\n";
}

auto SemanticsIR::StringifyNode(SemanticsNodeId node_id) -> std::string {
  std::string str;
  llvm::raw_string_ostream out(str);
  StringifyNodeImpl(out, node_id);
  return str;
}

auto SemanticsIR::StringifyNodeImpl(llvm::raw_ostream& out,
                                    SemanticsNodeId node_id) -> void {
  // Invalid node IDs will use the default invalid printing.
  if (!node_id.is_valid()) {
    out << node_id;
    return;
  }

  // Builtins have designated labels.
  if (node_id.index < SemanticsBuiltinKind::ValidCount) {
    out << SemanticsBuiltinKind::FromInt(node_id.index).label();
    return;
  }

  auto node = GetNode(node_id);
  switch (node.kind()) {
    case SemanticsNodeKind::StructType: {
      out << "{";
      auto refs = GetNodeBlock(node.GetAsStructType().second);
      llvm::ListSeparator sep;
      for (const auto& ref_id : refs) {
        out << sep;
        // TODO: Bound recursion depth or remove recursive step.
        StringifyNodeImpl(out, ref_id);
      }
      out << "}";
      break;
    }
    case SemanticsNodeKind::StructTypeField: {
      out << "." << GetString(node.GetAsStructTypeField()) << ": ";
      StringifyNodeImpl(out, node.type_id());
      break;
    }
    case SemanticsNodeKind::Assign:
    case SemanticsNodeKind::BinaryOperatorAdd:
    case SemanticsNodeKind::BindName:
    case SemanticsNodeKind::Builtin:
    case SemanticsNodeKind::Call:
    case SemanticsNodeKind::CodeBlock:
    case SemanticsNodeKind::CrossReference:
    case SemanticsNodeKind::FunctionDeclaration:
    case SemanticsNodeKind::FunctionDefinition:
    case SemanticsNodeKind::IntegerLiteral:
    case SemanticsNodeKind::RealLiteral:
    case SemanticsNodeKind::Return:
    case SemanticsNodeKind::ReturnExpression:
    case SemanticsNodeKind::StringLiteral:
    case SemanticsNodeKind::StructMemberAccess:
    case SemanticsNodeKind::StructValue:
    case SemanticsNodeKind::StubReference:
    case SemanticsNodeKind::VarStorage:
      // We don't need to handle stringification for nodes that don't show up in
      // errors, but make it clear what's going on so that it's clearer when
      // stringification is needed.
      out << "<cannot stringify " << node_id << ">";
      return;
    case SemanticsNodeKind::Invalid:
      llvm_unreachable("SemanticsNodeKind::Invalid is never used.");
  }
}

}  // namespace Carbon