import java.io.IOException;

import java.nio.file.*;

import java.util.*;

import java.util.stream.Collectors;

/**

* Parses the markdown content to extract project entries and saves it in a temporary file.

*

* Usage: java step_2_parse_projects.java [input_file] [output_file]

*/

void main(String[] args) throws IOException {

var inputPath = args.length > 0 ? Path.of(args[0]) : Path.of(Constants.CONTRIBUTE_README_FILE);

var tmpDir = FileUtils.ensureTmpDirectory();

var outputPath = args.length > 1 ? Path.of(args[1]) : tmpDir.resolve(Constants.PARSED_PROJECTS_FILE);

System.out.println("Step 2: Parsing project entries...");

System.out.printf("Input: %s%n", inputPath.toAbsolutePath());

System.out.printf("Output: %s%n", outputPath.toAbsolutePath());

FileUtils.validateInputFile(inputPath);

var content = FileUtils.readFileContent(inputPath);

var projectEntries = parseProjectEntries(content);

writeParsedEntries(outputPath, projectEntries);

System.out.printf(

"SUCCESS: Successfully parsed %d project entries!%n",

projectEntries.size()

);

System.out.printf(

"GitHub repos: %d%n",

projectEntries.stream().filter(ProjectEntry::isGitHubRepo).count()

);

}

/**

* Parses project entries from markdown content.

*/

List<ProjectEntry> parseProjectEntries(String content) {

var lines = content.lines().toArray(String[]::new);

var projectEntries = new ArrayList<ProjectEntry>();

var inProjectSection = false;

var currentSection = "";

var currentLevel4Section = "";

for (int i = 0; i < lines.length; i++) {

var line = lines[i];

var isSubsection = line.startsWith(Constants.SUBSECTION);

var isLevel4Section = line.startsWith("####");

// Check if we're entering the Projects section

if (line.startsWith(Constants.PROJECTS_SECTION)) {

inProjectSection = true;

continue;

}

// Check if we're leaving the Projects section

if (inProjectSection &&

line.startsWith(Constants.SECTION) &&

!isSubsection &&

!line.equals(Constants.PROJECTS_SECTION)

) {

inProjectSection = false;

}

if (!inProjectSection) {

continue;

}

// Track current level 3 subsection

if (isSubsection) {

currentSection = line.substring(Constants.SUBSECTION.length());

currentLevel4Section = ""; // Reset level 4 when we hit a new level 3

continue;

}

// Track current level 4 subsection

if (isLevel4Section) {

currentLevel4Section = line.substring(4).trim(); // Remove "#### "

continue;

}

// Skip headers and empty lines

var isHeader = (line.startsWith("_") && line.endsWith("_"));

if (isHeader || line.isBlank()) {

continue;

}

// List entries

if (line.matches(Constants.ENTRY_PATTERN)) {

// Combine level 3 and level 4 sections if level 4 exists

var fullSection = currentLevel4Section.isEmpty()

? currentSection

: currentSection + "/" + currentLevel4Section;

var projectEntry = parseProjectEntry(lines, i, fullSection);

if (projectEntry != null) {

projectEntries.add(projectEntry);

i += projectEntry.linesToSkip() - 1;

}

}

}

return projectEntries;

}

/**

* Parses a single project entry from the list format.

*/

ProjectEntry parseProjectEntry(String[] lines, int startIndex, String section) {

var matcher = Constants.PROJECT_PATTERN.matcher(lines[startIndex]);

if (matcher.find()) {

var name = matcher.group(1);

var url = matcher.group(2);

var description = new StringBuilder(matcher.group(3));

var linesToSkip = 1;

// Handle multi-line descriptions

for (int i = startIndex + 1; i < lines.length; i++) {

var nextLine = lines[i];

if (nextLine.isBlank() ||

nextLine.startsWith(Constants.SECTION) ||

nextLine.startsWith(Constants.SUBSECTION) ||

nextLine.startsWith("####") ||

nextLine.matches(Constants.ENTRY_PATTERN)

) {

break;

}

if (nextLine.matches(Constants.INDENTED_LINE_PATTERN)) {

description.append(" ").append(nextLine.trim());

linesToSkip++;

} else if (!nextLine.trim().isEmpty()) {

description.append(" ").append(nextLine.trim());

linesToSkip++;

}

}

return new ProjectEntry(

name,

url,

description.toString(),

linesToSkip,

section

);

}

return null;

}

/**

* Writes parsed entries to a temporary file in a simple format.

*/

void writeParsedEntries(Path outputPath, List<ProjectEntry> entries) throws IOException {

var content = entries.stream()

.map(e -> """

%s%s

%s%s

%s%s

%s%d

%s%s

%s

""".formatted(

Constants.NAME_PREFIX, e.name(),

Constants.URL_PREFIX, e.url(),

Constants.DESC_PREFIX, e.description(),

Constants.SKIP_PREFIX, e.linesToSkip(),

Constants.SECTION_PREFIX, e.section(),

Constants.SECTION_SEPARATOR

))

.collect(Collectors.joining("\n"));

FileUtils.writeOutputFile(outputPath, content);

}