/++
  Author: Aziz Köksal
  License: GPL3
+/
module cmd.Statistics;

import cmd.ASTStats;
import dil.lexer.Lexer;
import dil.lexer.Token;
import dil.parser.Parser;
import dil.ast.NodesEnum;
import dil.SourceText;
import common;

/// The statistics comman.
struct StatsCommand
{
  string[] filePaths; /// Module file paths.
  bool printTokensTable; /// Whether to print the tokens table.
  bool printNodesTable; /// Whether to print the nodes table.

  /// Execute the command.
  void run()
  {
    Statistics[] stats;
    foreach (filePath; filePaths)
      stats ~= getStatistics(filePath, printTokensTable, printNodesTable);

    auto total = Statistics(printTokensTable, printNodesTable);

    foreach (i, ref stat; stats)
    {
      total += stat;
      Stdout.formatln(
        "----\n"
        "File: {}\n"
        "Whitespace character count: {}\n"
        "Whitespace token count: {}\n"
        "Keyword count: {}\n"
        "Identifier count: {}\n"
        "Number count: {}\n"
        "Comment count: {}\n"
        "All tokens count: {}\n"
        "Lines of code: {}",
        filePaths[i],
        stat.whitespaceCount,
        stat.wsTokenCount,
        stat.keywordCount,
        stat.identCount,
        stat.numberCount,
        stat.commentCount,
        stat.tokenCount,
        stat.linesOfCode
      );
    }

    if (filePaths.length > 1)
    {
      Stdout.formatln(
        "--------------------------------------------------------------------------------\n"
        "Total of {} files:\n"
        "Whitespace character count: {}\n"
        "Whitespace token count: {}\n"
        "Keyword count: {}\n"
        "Identifier count: {}\n"
        "Number count: {}\n"
        "Comment count: {}\n"
        "All tokens count: {}\n"
        "Lines of code: {}",
        filePaths.length,
        total.whitespaceCount,
        total.wsTokenCount,
        total.keywordCount,
        total.identCount,
        total.numberCount,
        total.commentCount,
        total.tokenCount,
        total.linesOfCode
      );
    }

    if (printTokensTable)
    {
      Stdout("Table of tokens:").newline;
      Stdout.formatln(" {,10} | {}", "Count", "Token kind");
      Stdout("-----------------------------").newline;
      foreach (i, count; total.tokensTable)
        Stdout.formatln(" {,10} | {}", count, Token.toString(cast(TOK)i));
      Stdout("// End of tokens table.").newline;
    }

    if(printNodesTable)
    {
      Stdout("Table of nodes:").newline;
      Stdout.formatln(" {,10} | {}", "Count", "Node kind");
      Stdout("-----------------------------").newline;
      foreach (i, count; total.nodesTable)
        Stdout.formatln(" {,10} | {}", count, g_classNames[i]);
      Stdout("// End of nodes table.").newline;
    }
  }
}

/// A group of statistics variables.
struct Statistics
{
  uint whitespaceCount; /// Counter for whitespace characters.
  uint wsTokenCount;    /// Counter for all whitespace tokens.
  uint keywordCount;    /// Counter for keywords.
  uint identCount;      /// Counter for identifiers.
  uint numberCount;     /// Counter for number literals.
  uint commentCount;    /// Counter for comments.
  uint tokenCount;      /// Counter for all tokens produced by the Lexer.
  uint linesOfCode;     /// Number of lines.
  uint[] tokensTable;   /// Table of counters for all token kinds.
  uint[] nodesTable;    /// Table of counters for all node kinds.

  static Statistics opCall(bool allocateTokensTable, bool allocateNodesTable = false)
  {
    Statistics s;
    if (allocateTokensTable)
      s.tokensTable = new uint[TOK.MAX];
    if (allocateNodesTable)
      s.nodesTable = new uint[g_classNames.length];
    return s;
  }

  void opAddAssign(Statistics s)
  {
    this.whitespaceCount += s.whitespaceCount;
    this.wsTokenCount    += s.wsTokenCount;
    this.keywordCount    += s.keywordCount;
    this.identCount      += s.identCount;
    this.numberCount     += s.numberCount;
    this.commentCount    += s.commentCount;
    this.tokenCount      += s.tokenCount;
    this.linesOfCode     += s.linesOfCode;
    foreach (i, count; s.tokensTable)
      this.tokensTable[i] += count;
    foreach (i, count; s.nodesTable)
      this.nodesTable[i] += count;
  }
}

/// Executes the statistics command.
void execute(string[] filePaths, bool printTokensTable, bool printNodesTable)
{

}

/// Returns the statistics for a D source file.
Statistics getStatistics(string filePath, bool printTokensTable, bool printNodesTable)
{
  // Create a new record.
  auto stats = Statistics(printTokensTable);

  auto sourceText = new SourceText(filePath, true);
  Parser parser;
  Lexer lx;
  if (printNodesTable)
  {
    parser = new Parser(sourceText);
    auto rootNode = parser.start();
    // Count nodes.
    stats.nodesTable = (new ASTStats).count(rootNode);
    lx = parser.lexer;
  }
  else
  {
    lx = new Lexer(sourceText);
    lx.scanAll();
  }

  auto token = lx.firstToken();

  // Count tokens.
  // Lexer creates HEAD + Newline, which are not in the source text.
  // No token left behind!
  stats.tokenCount = 2;
  stats.linesOfCode = lx.lineNum;
  if (printTokensTable)
  {
    stats.tokensTable[TOK.HEAD] = 1;
    stats.tokensTable[TOK.Newline] = 1;
  }
  // Traverse linked list.
  while (1)
  {
    stats.tokenCount += 1;

    if (printTokensTable)
      stats.tokensTable[token.kind] += 1;

    // Count whitespace characters
    if (token.ws !is null)
      stats.whitespaceCount += token.start - token.ws;

    switch (token.kind)
    {
    case TOK.Identifier:
      stats.identCount++;
      break;
    case TOK.Comment:
      stats.commentCount++;
      break;
    case TOK.Int32, TOK.Int64, TOK.Uint32, TOK.Uint64,
         TOK.Float32, TOK.Float64, TOK.Float80,
         TOK.Imaginary32, TOK.Imaginary64, TOK.Imaginary80:
      stats.numberCount++;
      break;
    case TOK.Newline:
      break;
    default:
      if (token.isKeyword)
        stats.keywordCount++;
      else if (token.isWhitespace)
        stats.wsTokenCount++;
    }

    if (token.next is null)
      break;
    token = token.next;
  }
  assert(token.kind == TOK.EOF);
  return stats;
}