// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "garnet/bin/zxdb/console/line_input.h"
#include "gtest/gtest.h"

namespace zxdb {

namespace {

// Some common terminal codes.
#define TERM_UP "\x1b[A"
#define TERM_DOWN "\x1b[B"
#define TERM_LEFT "\x1b[D"
#define TERM_RIGHT "\x1b[C"

// Dummy completion functions that return two completions.
std::vector<std::string> CompletionCallback(const std::string& line) {
  std::vector<std::string> result;
  result.push_back("one");
  result.push_back("two");
  return result;
}

}  // namespace

class TestLineInput : public LineInputBase {
 public:
  TestLineInput(const std::string& prompt) : LineInputBase(prompt) {}

  void ClearOutput() { output_.clear(); }
  std::string GetAndClearOutput() {
    std::string ret = output_;
    ClearOutput();
    return ret;
  }

  // This input takes a string instead of one character at a time, returning
  // the result of the last one.
  bool OnInputStr(const std::string& input) {
    bool result = false;
    for (char c : input)
      result = OnInput(c);
    return result;
  }

 protected:
  void Write(const std::string& data) { output_.append(data); }

 private:
  std::string output_;
};

TEST(LineInput, CursorCommands) {
  std::string prompt("Prompt ");
  TestLineInput input(prompt);

  // Basic prompt. "7C" at the end means cursor is @ 7th character.
  input.BeginReadLine();
  EXPECT_EQ("\rPrompt \x1b[0K\r\x1B[7C", input.GetAndClearOutput());

  // Basic input with enter.
  EXPECT_FALSE(input.OnInput('a'));
  EXPECT_FALSE(input.OnInput('b'));
  EXPECT_TRUE(input.OnInput('\r'));
  EXPECT_EQ("ab", input.line());

  input.BeginReadLine();
  EXPECT_FALSE(input.OnInputStr("abcd"));
  EXPECT_EQ(4u, input.pos());

  // Basic cursor movement.
  EXPECT_FALSE(input.OnInput(2));  // Control-B = left.
  EXPECT_EQ(3u, input.pos());
  EXPECT_FALSE(input.OnInput(6));  // Control-F = right.
  EXPECT_EQ(4u, input.pos());
  EXPECT_FALSE(input.OnInput(1));  // Control-A = home.
  EXPECT_EQ(0u, input.pos());
  EXPECT_FALSE(input.OnInput(5));  // Control-E = end.
  EXPECT_EQ(4u, input.pos());

  // Longer escaped sequences.
  EXPECT_FALSE(input.OnInputStr("\x1b[D"));  // Left.
  EXPECT_EQ(3u, input.pos());
  EXPECT_FALSE(input.OnInputStr("\x1b[C"));  // Right.
  EXPECT_EQ(4u, input.pos());
  EXPECT_FALSE(input.OnInputStr("\x1b[H"));  // Home.
  EXPECT_EQ(0u, input.pos());
  EXPECT_FALSE(input.OnInputStr("\x1b[F"));  // End.
  EXPECT_EQ(4u, input.pos());

  // Backspace.
  EXPECT_FALSE(input.OnInput(127));  // Backspace.
  EXPECT_EQ(3u, input.pos());
  EXPECT_EQ("abc", input.line());

  // Delete. This one also tests the line refresh commands.
  EXPECT_FALSE(input.OnInput(1));  // Home.
  input.ClearOutput();
  EXPECT_FALSE(input.OnInputStr("\x1b[3~"));
  EXPECT_EQ("bc", input.line());
  // "7C" at the end means cursor is at the 7th character (the "b").
  EXPECT_EQ("\rPrompt bc\x1b[0K\r\x1B[7C", input.GetAndClearOutput());
  EXPECT_EQ(0u, input.pos());
}

TEST(LineInput, History) {
  TestLineInput input("");

  // Make some history.
  input.AddToHistory("one");
  input.AddToHistory("two");

  // Go up twice.
  input.BeginReadLine();
  EXPECT_FALSE(input.OnInputStr(TERM_UP TERM_UP));

  // Should have selected the first line and the cursor should be at the end.
  EXPECT_EQ("one", input.line());
  EXPECT_EQ(3u, input.pos());

  // Append a letter and accept it.
  input.OnInputStr("s\r");
  input.AddToHistory(input.line());

  // Start editing a new line with some input.
  input.BeginReadLine();
  input.OnInputStr("three");

  // Check history. Should be:
  //  ones
  //  two
  //  ones
  //  three
  EXPECT_EQ("three", input.line());
  EXPECT_FALSE(input.OnInputStr(TERM_UP));
  EXPECT_EQ("ones", input.line());
  EXPECT_FALSE(input.OnInputStr(TERM_UP));
  EXPECT_EQ("two", input.line());
  EXPECT_FALSE(input.OnInputStr(TERM_UP));
  EXPECT_FALSE(input.OnInputStr(TERM_UP));  // From here, these are extra to
  EXPECT_FALSE(input.OnInputStr(TERM_UP));  // test that going beyond the top
  EXPECT_FALSE(input.OnInputStr(TERM_UP));  // stays stopped.
  EXPECT_EQ("ones", input.line());

  // Going back to the bottom (also doing one extra one to test the boundary).
  EXPECT_FALSE(input.OnInputStr(TERM_DOWN TERM_DOWN TERM_DOWN TERM_DOWN));

  // Should have gotten the original non-accepted input back.
  EXPECT_EQ("three", input.line());
}

TEST(LineInput, Completions) {
  TestLineInput input("");
  input.set_completion_callback(&CompletionCallback);

  input.BeginReadLine();
  input.OnInput('z');

  // Send one tab, should get the first suggestion.
  input.OnInput(9);
  EXPECT_EQ("one", input.line());
  EXPECT_EQ(3u, input.pos());

  // Second suggestion.
  input.OnInput(9);
  EXPECT_EQ("two", input.line());
  EXPECT_EQ(3u, input.pos());

  // Again should go back to original text.
  input.OnInput(9);
  EXPECT_EQ("z", input.line());
  EXPECT_EQ(1u, input.pos());

  // Should wrap around to the first suggestion.
  input.OnInput(9);
  EXPECT_EQ("one", input.line());
  EXPECT_EQ(3u, input.pos());

  // Typing should append.
  input.OnInput('s');
  EXPECT_EQ("ones", input.line());
  EXPECT_EQ(4u, input.pos());

  // Tab again should give the same suggestions.
  input.OnInput(9);
  EXPECT_EQ("one", input.line());
  EXPECT_EQ(3u, input.pos());

  // Send an escape sequence "left" which should accept the suggestion and
  // execute the sequence.
  input.OnInputStr("\x1b[D");
  EXPECT_EQ("one", input.line());
  EXPECT_EQ(2u, input.pos());
}

TEST(LineInput, Scroll) {
  TestLineInput input("ABCDE");
  input.set_max_cols(10);

  input.BeginReadLine();
  input.ClearOutput();

  // Write up to the 9th character, which should be the last character printed
  // until scrolling starts. It should have used the optimized "just write the
  // characters" code path for everything after the prompt.
  EXPECT_FALSE(input.OnInputStr("FGHI"));
  EXPECT_EQ("FGHI", input.GetAndClearOutput());

  // Add a 10th character. The whole line should scroll one to the left,
  // leaving the cursor at the last column (colum offset 9 = "9C" at the end).
  EXPECT_FALSE(input.OnInput('J'));
  EXPECT_EQ("\rBCDEFGHIJ\x1b[0K\r\x1B[9C", input.GetAndClearOutput());

  // Move left, the line should scroll back.
  EXPECT_FALSE(input.OnInput(2));  // 2 = Control-B.
  EXPECT_EQ("\rABCDEFGHIJ\x1b[0K\r\x1B[9C", input.GetAndClearOutput());
}

TEST(LineInput, NegAck) {
  TestLineInput input("ABCDE");
  input.BeginReadLine();

  // Empty should remain with them prompt.
  EXPECT_FALSE(input.OnInput(21));  // 21 = Control-U
  EXPECT_EQ(input.line(), "");

  // Adding characters and then Control-U should clear.
  input.OnInputStr("12345");
  EXPECT_FALSE(input.OnInput(21));  // 21 = Control-U
  EXPECT_EQ(input.line(), "");

  // In the middle of the line should clear until the cursor.
  input.OnInputStr("0123456789");
  EXPECT_FALSE(input.OnInputStr(TERM_LEFT));
  EXPECT_FALSE(input.OnInputStr(TERM_LEFT));
  EXPECT_FALSE(input.OnInputStr(TERM_LEFT));
  EXPECT_FALSE(input.OnInputStr(TERM_LEFT));
  EXPECT_FALSE(input.OnInput(21));  // 21 = Control-U
  EXPECT_EQ(input.line(), "6789");
  EXPECT_EQ(input.pos(), 0u);
}

}  // namespace zxdb