src/main/java/de/uapcore/lightpit/modules/ProjectsModule.java

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2018 Mike Becker. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */
package de.uapcore.lightpit.modules;


import de.uapcore.lightpit.*;
import de.uapcore.lightpit.dao.DataAccessObjects;
import de.uapcore.lightpit.entities.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.sql.Date;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.Objects;

import static de.uapcore.lightpit.Functions.fqn;

@LightPITModule(
        bundleBaseName = "localization.projects",
        modulePath = "projects",
        defaultPriority = 20
)
@WebServlet(
        name = "ProjectsModule",
        urlPatterns = "/projects/*"
)
public final class ProjectsModule extends AbstractLightPITServlet {

    private static final Logger LOG = LoggerFactory.getLogger(ProjectsModule.class);

    public static final String SESSION_ATTR_SELECTED_PROJECT = fqn(ProjectsModule.class, "selected-project");
    public static final String SESSION_ATTR_SELECTED_ISSUE = fqn(ProjectsModule.class, "selected-issue");
    public static final String SESSION_ATTR_SELECTED_VERSION = fqn(ProjectsModule.class, "selected-version");

    private class SessionSelection {
        final HttpSession session;
        Project project;
        Version version;
        Issue issue;

        SessionSelection(HttpServletRequest req, Project project) {
            this.session = req.getSession();
            this.project = project;
            version = null;
            issue = null;
            updateAttributes();
        }

        SessionSelection(HttpServletRequest req, DataAccessObjects dao) throws SQLException {
            this.session = req.getSession();
            final var issueDao = dao.getIssueDao();
            final var projectDao = dao.getProjectDao();
            final var issueSelection = getParameter(req, Integer.class, "issue");
            if (issueSelection.isPresent()) {
                issue = issueDao.find(issueSelection.get());
            } else {
                final var issue = (Issue) session.getAttribute(SESSION_ATTR_SELECTED_ISSUE);
                this.issue = issue == null ? null : issueDao.find(issue.getId());
            }
            if (issue != null) {
                version = null; // show the issue globally
                project = projectDao.find(issue.getProject().getId());
            }

            final var projectSelection = getParameter(req, Integer.class, "pid");
            if (projectSelection.isPresent()) {
                final var selectedProject = projectDao.find(projectSelection.get());
                if (!Objects.equals(selectedProject, project)) {
                    // reset version and issue if project changed
                    version = null;
                    issue = null;
                }
                project = selectedProject;
            } else {
                final var sessionProject = (Project) session.getAttribute(SESSION_ATTR_SELECTED_PROJECT);
                project = sessionProject == null ? null : projectDao.find(sessionProject.getId());
            }
            updateAttributes();
        }

        void selectVersion(Version version) {
            if (!Objects.equals(project, version.getProject())) throw new AssertionError("Nice, you implemented a bug!");
            this.version = version;
            this.issue = null;
            updateAttributes();
        }

        void selectIssue(Issue issue) {
            if (!Objects.equals(issue.getProject(), project)) throw new AssertionError("Nice, you implemented a bug!");
            this.issue = issue;
            this.version = null;
            updateAttributes();
        }

        void updateAttributes() {
            session.setAttribute(SESSION_ATTR_SELECTED_PROJECT, project);
            session.setAttribute(SESSION_ATTR_SELECTED_VERSION, version);
            session.setAttribute(SESSION_ATTR_SELECTED_ISSUE, issue);
        }
    }


    /**
     * Creates the breadcrumb menu.
     *
     * @param level           the current active level (0: root, 1: project, 2: version, 3: issue)
     * @param sessionSelection the currently selected objects
     * @return a dynamic breadcrumb menu trying to display as many levels as possible
     */
    private List<MenuEntry> getBreadcrumbs(int level, SessionSelection sessionSelection) {
        MenuEntry entry;

        final var breadcrumbs = new ArrayList<MenuEntry>();
        entry = new MenuEntry(new ResourceKey("localization.projects", "menuLabel"),
                "projects/", 0);
        breadcrumbs.add(entry);
        if (level == 0) entry.setActive(true);

        if (sessionSelection.project != null) {
            if (sessionSelection.project.getId() < 0) {
                entry = new MenuEntry(new ResourceKey("localization.projects", "button.create"),
                        "projects/edit", 1);
            } else {
                entry = new MenuEntry(sessionSelection.project.getName(),
                        "projects/view?pid=" + sessionSelection.project.getId(), 1);
            }
            if (level == 1) entry.setActive(true);
            breadcrumbs.add(entry);
        }

        if (sessionSelection.version != null) {
            if (sessionSelection.version.getId() < 0) {
                entry = new MenuEntry(new ResourceKey("localization.projects", "button.version.create"),
                        "projects/versions/edit", 2);
            } else {
                entry = new MenuEntry(sessionSelection.version.getName(),
                        // TODO: change link to issue overview for that version
                        "projects/versions/edit?id=" + sessionSelection.version.getId(), 2);
            }
            if (level == 2) entry.setActive(true);
            breadcrumbs.add(entry);
        }

        if (sessionSelection.issue != null) {
            entry = new MenuEntry(new ResourceKey("localization.projects", "menu.issues"),
                    // TODO: change link to a separate issue view (maybe depending on the selected version)
                    "projects/view?pid=" + sessionSelection.issue.getProject().getId(), 3);
            breadcrumbs.add(entry);
            if (sessionSelection.issue.getId() < 0) {
                entry = new MenuEntry(new ResourceKey("localization.projects", "button.issue.create"),
                        "projects/issues/edit", 2);
            } else {
                entry = new MenuEntry("#" + sessionSelection.issue.getId(),
                        // TODO: maybe change link to a view rather than directly opening the editor
                        "projects/issues/edit?id=" + sessionSelection.issue.getId(), 4);
            }
            if (level == 3) entry.setActive(true);
            breadcrumbs.add(entry);
        }

        return breadcrumbs;
    }

    @RequestMapping(method = HttpMethod.GET)
    public ResponseType index(HttpServletRequest req, DataAccessObjects dao) throws SQLException {
        final var sessionSelection = new SessionSelection(req, dao);
        final var projectList = dao.getProjectDao().list();
        req.setAttribute("projects", projectList);
        setContentPage(req, "projects");
        setStylesheet(req, "projects");

        setBreadcrumbs(req, getBreadcrumbs(0, sessionSelection));

        return ResponseType.HTML;
    }

    private void configureEditForm(HttpServletRequest req, DataAccessObjects dao, SessionSelection selection) throws SQLException {
        req.setAttribute("project", selection.project);
        req.setAttribute("users", dao.getUserDao().list());
        setContentPage(req, "project-form");
        setBreadcrumbs(req, getBreadcrumbs(1, selection));
    }

    @RequestMapping(requestPath = "edit", method = HttpMethod.GET)
    public ResponseType edit(HttpServletRequest req, DataAccessObjects dao) throws SQLException {
        final var selection = new SessionSelection(req, findByParameter(req, Integer.class, "id",
                dao.getProjectDao()::find).orElse(new Project(-1)));

        configureEditForm(req, dao, selection);

        return ResponseType.HTML;
    }

    @RequestMapping(requestPath = "commit", method = HttpMethod.POST)
    public ResponseType commit(HttpServletRequest req, DataAccessObjects dao) throws SQLException {

        Project project = new Project(-1);
        try {
            project = new Project(getParameter(req, Integer.class, "id").orElseThrow());
            project.setName(getParameter(req, String.class, "name").orElseThrow());
            getParameter(req, String.class, "description").ifPresent(project::setDescription);
            getParameter(req, String.class, "repoUrl").ifPresent(project::setRepoUrl);
            getParameter(req, Integer.class, "owner").map(
                    ownerId -> ownerId >= 0 ? new User(ownerId) : null
            ).ifPresent(project::setOwner);

            dao.getProjectDao().saveOrUpdate(project);

            setRedirectLocation(req, "./projects/");
            setContentPage(req, Constants.JSP_COMMIT_SUCCESSFUL);
            LOG.debug("Successfully updated project {}", project.getName());
        } catch (NoSuchElementException | IllegalArgumentException | SQLException ex) {
            // TODO: set request attribute with error text
            LOG.warn("Form validation failure: {}", ex.getMessage());
            LOG.debug("Details:", ex);
            configureEditForm(req, dao, new SessionSelection(req, project));
        }

        return ResponseType.HTML;
    }

    @RequestMapping(requestPath = "view", method = HttpMethod.GET)
    public ResponseType view(HttpServletRequest req, HttpServletResponse resp, DataAccessObjects dao) throws IOException, SQLException {
        final var sessionSelection = new SessionSelection(req, dao);

        req.setAttribute("versions", dao.getVersionDao().list(sessionSelection.project));
        req.setAttribute("issues", dao.getIssueDao().list(sessionSelection.project));

        setBreadcrumbs(req, getBreadcrumbs(1, sessionSelection));
        setContentPage(req, "project-details");

        return ResponseType.HTML;
    }

    private void configureEditVersionForm(HttpServletRequest req, DataAccessObjects dao, SessionSelection selection) throws SQLException {
        req.setAttribute("projects", dao.getProjectDao().list());
        req.setAttribute("version", selection.version);
        req.setAttribute("versionStatusEnum", VersionStatus.values());

        setContentPage(req, "version-form");
        setBreadcrumbs(req, getBreadcrumbs(2, selection));
    }

    @RequestMapping(requestPath = "versions/edit", method = HttpMethod.GET)
    public ResponseType editVersion(HttpServletRequest req, HttpServletResponse resp, DataAccessObjects dao) throws IOException, SQLException {
        final var sessionSelection = new SessionSelection(req, dao);

        sessionSelection.selectVersion(findByParameter(req, Integer.class, "id", dao.getVersionDao()::find)
                .orElse(new Version(-1, sessionSelection.project)));
        configureEditVersionForm(req, dao, sessionSelection);

        return ResponseType.HTML;
    }

    @RequestMapping(requestPath = "versions/commit", method = HttpMethod.POST)
    public ResponseType commitVersion(HttpServletRequest req, HttpServletResponse resp, DataAccessObjects dao) throws IOException, SQLException {
        final var sessionSelection = new SessionSelection(req, dao);

        var version = new Version(-1, sessionSelection.project);
        try {
            version = new Version(getParameter(req, Integer.class, "id").orElseThrow(), sessionSelection.project);
            version.setName(getParameter(req, String.class, "name").orElseThrow());
            getParameter(req, Integer.class, "ordinal").ifPresent(version::setOrdinal);
            version.setStatus(VersionStatus.valueOf(getParameter(req, String.class, "status").orElseThrow()));
            dao.getVersionDao().saveOrUpdate(version);

            // specifying the pid parameter will purposely reset the session selected version!
            setRedirectLocation(req, "./projects/view?pid="+sessionSelection.project.getId());
            setContentPage(req, Constants.JSP_COMMIT_SUCCESSFUL);
            LOG.debug("Successfully updated version {} for project {}", version.getName(), sessionSelection.project.getName());
        } catch (NoSuchElementException | IllegalArgumentException | SQLException ex) {
            // TODO: set request attribute with error text
            LOG.warn("Form validation failure: {}", ex.getMessage());
            LOG.debug("Details:", ex);
            sessionSelection.selectVersion(version);
            configureEditVersionForm(req, dao, sessionSelection);
        }

        return ResponseType.HTML;
    }

    private void configureEditIssueForm(HttpServletRequest req, DataAccessObjects dao, SessionSelection selection) throws SQLException {
        req.setAttribute("projects", dao.getProjectDao().list());
        req.setAttribute("issue", selection.issue);
        req.setAttribute("issueStatusEnum", IssueStatus.values());
        req.setAttribute("issueCategoryEnum", IssueCategory.values());
        req.setAttribute("users", dao.getUserDao().list());

        setContentPage(req, "issue-form");
        setBreadcrumbs(req, getBreadcrumbs(3, selection));
    }

    @RequestMapping(requestPath = "issues/edit", method = HttpMethod.GET)
    public ResponseType editIssue(HttpServletRequest req, HttpServletResponse resp, DataAccessObjects dao) throws IOException, SQLException {
        final var sessionSelection = new SessionSelection(req, dao);

        sessionSelection.selectIssue(findByParameter(req, Integer.class, "id",
                dao.getIssueDao()::find).orElse(new Issue(-1, sessionSelection.project)));
        configureEditIssueForm(req, dao, sessionSelection);

        return ResponseType.HTML;
    }

    @RequestMapping(requestPath = "issues/commit", method = HttpMethod.POST)
    public ResponseType commitIssue(HttpServletRequest req, HttpServletResponse resp, DataAccessObjects dao) throws IOException, SQLException {
        final var sessionSelection = new SessionSelection(req, dao);

        Issue issue = new Issue(-1, sessionSelection.project);
        try {
            issue = new Issue(getParameter(req, Integer.class, "id").orElseThrow(), sessionSelection.project);
            getParameter(req, String.class, "category").map(IssueCategory::valueOf).ifPresent(issue::setCategory);
            getParameter(req, String.class, "status").map(IssueStatus::valueOf).ifPresent(issue::setStatus);
            issue.setSubject(getParameter(req, String.class, "subject").orElseThrow());
            getParameter(req, Integer.class, "assignee").map(
                    userid -> userid >= 0 ? new User(userid) : null
            ).ifPresent(issue::setAssignee);
            getParameter(req, String.class, "description").ifPresent(issue::setDescription);
            getParameter(req, Date.class, "eta").ifPresent(issue::setEta);
            dao.getIssueDao().saveOrUpdate(issue);

            // TODO: redirect to issue overview
            // specifying the issue parameter keeps the edited issue as breadcrumb
            setRedirectLocation(req, "./projects/view?issue="+issue.getId());
            setContentPage(req, Constants.JSP_COMMIT_SUCCESSFUL);
            LOG.debug("Successfully updated issue {} for project {}", issue.getId(), sessionSelection.project.getName());
        } catch (NoSuchElementException | IllegalArgumentException | SQLException ex) {
            // TODO: set request attribute with error text
            LOG.warn("Form validation failure: {}", ex.getMessage());
            LOG.debug("Details:", ex);
            sessionSelection.selectIssue(issue);
            configureEditIssueForm(req, dao, sessionSelection);
        }

        return ResponseType.HTML;
    }
}