package com.aicheck.analyzer;

import com.aicheck.config.AppConfig;
import com.aicheck.git.GitChangeScanner;
import com.aicheck.model.ChangedClassFile;
import com.aicheck.model.ClassChangeReport;
import com.aicheck.model.FieldChange;
import com.aicheck.model.FieldInfo;
import com.aicheck.parser.ClassFieldParser;

import java.io.IOException;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

public class ClassChangeAnalyzer {
    private final GitChangeScanner gitScanner;
    private final ClassFieldParser classFieldParser = new ClassFieldParser();
    private final FieldDiffEngine fieldDiffEngine = new FieldDiffEngine();
    private final ImpactAnalyzer impactAnalyzer = new ImpactAnalyzer();

    public ClassChangeAnalyzer(GitChangeScanner gitScanner) {
        this.gitScanner = gitScanner;
    }

    public List<ClassChangeReport> analyze(Path repoRoot, AppConfig config, String oldSha, String newSha,
                                           Map<String, com.aicheck.model.ApiEndpoint> endpointIndex) throws IOException {
        List<ChangedClassFile> changedFiles = gitScanner.scanChangedClasses(oldSha, newSha);
        List<ClassChangeReport> reports = new ArrayList<>();

        for (ChangedClassFile changedFile : changedFiles) {
            if (changedFile.getStatus() == ChangedClassFile.ChangeStatus.DELETED) {
                ClassChangeReport report = new ClassChangeReport(
                        changedFile.getClassName(),
                        changedFile.getClassType(),
                        changedFile.getRelativePath(),
                        true,
                        config.isDtoEntityConversionEnabled()
                );
                String oldSource = gitScanner.readFileAtCommit(oldSha, changedFile.getRelativePath());
                impactAnalyzer.analyze(report, endpointIndex, config, repoRoot, oldSource);
                reports.add(report);
                continue;
            }

            String oldSource = gitScanner.readFileAtCommit(oldSha, changedFile.getRelativePath());
            String newSource = gitScanner.readFileAtCommit(newSha, changedFile.getRelativePath());
            if (newSource == null || newSource.isBlank()) {
                newSource = gitScanner.readFileAtHead(changedFile.getRelativePath());
            }
            List<FieldInfo> oldFields = classFieldParser.parseFields(oldSource, changedFile.getClassName());
            List<FieldInfo> newFields = classFieldParser.parseFields(newSource, changedFile.getClassName());
            List<FieldChange> fieldChanges = fieldDiffEngine.diff(oldFields, newFields);
            if (fieldChanges.isEmpty()) {
                continue;
            }

            ClassChangeReport report = new ClassChangeReport(
                    changedFile.getClassName(),
                    changedFile.getClassType(),
                    changedFile.getRelativePath(),
                    false,
                    config.isDtoEntityConversionEnabled()
            );
            fieldChanges.forEach(report::addFieldChange);
            impactAnalyzer.analyze(report, endpointIndex, config, repoRoot, newSource);
            reports.add(report);
        }
        return reports;
    }
}