/*
 * Copyright 2016 The Bazel Authors. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.google.idea.blaze.base.projectview.parser;

import com.google.common.collect.Lists;
import com.google.idea.blaze.base.projectview.section.SectionParser;
import com.google.idea.blaze.base.scope.BlazeContext;
import com.google.idea.blaze.base.scope.output.IssueOutput;
import com.google.idea.blaze.base.sync.workspace.WorkspacePathResolver;
import com.google.idea.blaze.base.ui.BlazeValidationError;
import org.jetbrains.annotations.Nullable;

import java.io.File;
import java.util.List;

/**
 * Context for the project view parser.
 */
public class ParseContext {
  private final BlazeContext context;
  private final WorkspacePathResolver workspacePathResolver;
  @Nullable private final File file;
  private final List<String> lines;

  @Nullable private Line currentLine;
  private int currentLineIndex;

  public static class Line {
    public final String text;
    public final int indent;
    public Line(String text, int indent) {
      this.text = text;
      this.indent = indent;
    }
  }

  public ParseContext(BlazeContext context, WorkspacePathResolver workspacePathResolver, @Nullable File file, String text) {
    this.context = context;
    this.workspacePathResolver = workspacePathResolver;
    this.file = file;
    this.lines = Lists.newArrayList(text.split("\n"));
    this.currentLine = null;
    this.currentLineIndex = -1;
    consume();
  }

  public Line current() {
    assert currentLine != null;
    return currentLine;
  }

  public void consume() {
    while (++currentLineIndex < lines.size()) {
      String line = lines.get(currentLineIndex);
      int indent = 0;
      while (indent < line.length() && line.charAt(indent) == ' ') {
        ++indent;
      }
      if (!indentationCorrect(indent)) {
        addError(String.format("Invalid indentation. Project view files are indented with %d spaces.", SectionParser.INDENT));
        continue;
      }

      line = line.trim();
      if (!shouldSkipLine(line)) {
        currentLine = new Line(line, indent);
        break;
      }
    }
  }

  private boolean indentationCorrect(int indent) {
    return indent == 0 || indent == 2;
  }

  boolean shouldSkipLine(String line) {
    return line.isEmpty() || line.startsWith("#");
  }

  public boolean atEnd() {
    return currentLineIndex >= lines.size();
  }

  public BlazeContext getContext() {
    return context;
  }

  public WorkspacePathResolver getWorkspacePathResolver() {
    return workspacePathResolver;
  }

  @Nullable
  public File getProjectViewFile() {
    return file;
  }

  public void addErrors(List<BlazeValidationError> errors) {
    for (BlazeValidationError error : errors) {
      addError(error.getError());
    }
  }

  public void addError(String error) {
    IssueOutput
      .error(error)
      .inFile(file)
      .onLine(currentLineIndex)
      .submit(context);
  }
}