src/main/kotlin/de/uapcore/lightpit/servlet/ProjectServlet.kt

/*
 * Copyright 2021 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.servlet

import de.uapcore.lightpit.AbstractServlet
import de.uapcore.lightpit.HttpRequest
import de.uapcore.lightpit.dao.DataAccessObject
import de.uapcore.lightpit.entities.*
import de.uapcore.lightpit.types.IssueCategory
import de.uapcore.lightpit.types.IssueStatus
import de.uapcore.lightpit.types.VersionStatus
import de.uapcore.lightpit.types.WebColor
import de.uapcore.lightpit.util.AllFilter
import de.uapcore.lightpit.util.IssueFilter
import de.uapcore.lightpit.util.IssueSorter.Companion.DEFAULT_ISSUE_SORTER
import de.uapcore.lightpit.util.SpecificFilter
import de.uapcore.lightpit.viewmodel.*
import java.sql.Date
import javax.servlet.annotation.WebServlet

@WebServlet(urlPatterns = ["/projects/*"])
class ProjectServlet : AbstractServlet() {

    init {
        get("/", this::projects)
        get("/%project", this::project)
        get("/%project/issues/%version/%component/", this::project)
        get("/%project/edit", this::projectForm)
        get("/-/create", this::projectForm)
        post("/-/commit", this::projectCommit)

        get("/%project/versions/", this::versions)
        get("/%project/versions/%version/edit", this::versionForm)
        get("/%project/versions/-/create", this::versionForm)
        post("/%project/versions/-/commit", this::versionCommit)

        get("/%project/components/", this::components)
        get("/%project/components/%component/edit", this::componentForm)
        get("/%project/components/-/create", this::componentForm)
        post("/%project/components/-/commit", this::componentCommit)

        get("/%project/issues/%version/%component/%issue", this::issue)
        get("/%project/issues/%version/%component/%issue/edit", this::issueForm)
        post("/%project/issues/%version/%component/%issue/comment", this::issueComment)
        get("/%project/issues/%version/%component/-/create", this::issueForm)
        post("/%project/issues/%version/%component/-/commit", this::issueCommit)
    }

    private fun projects(http: HttpRequest, dao: DataAccessObject) {
        val projects = dao.listProjects()
        val projectInfos = projects.map {
            ProjectInfo(
                project = it,
                versions = dao.listVersions(it),
                components = emptyList(), // not required in this view
                issueSummary = dao.collectIssueSummary(it)
            )
        }

        with(http) {
            view = ProjectsView(projectInfos)
            navigationMenu = projectNavMenu(projects)
            styleSheets = listOf("projects")
            render("projects")
        }
    }

    private fun activeProjectNavMenu(
        projects: List<Project>,
        projectInfo: ProjectInfo,
        selectedVersion: Version? = null,
        selectedComponent: Component? = null
    ) =
        projectNavMenu(
            projects,
            projectInfo.versions,
            projectInfo.components,
            projectInfo.project,
            selectedVersion,
            selectedComponent
        )

    sealed class LookupResult<T> {
        class NotFound<T> : LookupResult<T>()
        data class Found<T>(val elem: T?) : LookupResult<T>()
    }

    private fun <T : HasNode> HttpRequest.lookupPathParam(paramName: String, list: List<T>): LookupResult<T> {
        val node = pathParams[paramName]
        return if (node == null || node == "-") {
            LookupResult.Found(null)
        } else {
            val result = list.find { it.node == node }
            if (result == null) {
                LookupResult.NotFound()
            } else {
                LookupResult.Found(result)
            }
        }
    }

    private fun obtainProjectInfo(http: HttpRequest, dao: DataAccessObject): ProjectInfo? {
        val project = dao.findProjectByNode(http.pathParams["project"] ?: "") ?: return null

        val versions: List<Version> = dao.listVersions(project)
        val components: List<Component> = dao.listComponents(project)

        return ProjectInfo(
            project,
            versions,
            components,
            dao.collectIssueSummary(project)
        )
    }

    private fun sanitizeNode(name: String): String {
        val san = name.replace(Regex("[/\\\\]"), "-")
        return if (san.startsWith(".")) {
            "v$san"
        } else {
            san
        }
    }

    private fun feedPath(project: Project) = "feed/${project.node}/issues.rss"

    data class PathInfos(
        val projectInfo: ProjectInfo,
        val version: Version?,
        val component: Component?
    ) {
        val project = projectInfo.project
        val issuesHref by lazyOf("projects/${project.node}/issues/${version?.node ?: "-"}/${component?.node ?: "-"}/")
    }

    private fun withPathInfo(http: HttpRequest, dao: DataAccessObject): PathInfos? {
        val projectInfo = obtainProjectInfo(http, dao)
        if (projectInfo == null) {
            http.response.sendError(404)
            return null
        }

        val version = when (val result = http.lookupPathParam("version", projectInfo.versions)) {
            is LookupResult.NotFound -> {
                http.response.sendError(404)
                return null
            }
            is LookupResult.Found -> {
                result.elem
            }
        }
        val component = when (val result = http.lookupPathParam("component", projectInfo.components)) {
            is LookupResult.NotFound -> {
                http.response.sendError(404)
                return null
            }
            is LookupResult.Found -> {
                result.elem
            }
        }

        return PathInfos(projectInfo, version, component)
    }

    private fun project(http: HttpRequest, dao: DataAccessObject) {
        withPathInfo(http, dao)?.run {

            val issues = dao.listIssues(IssueFilter(
                project = SpecificFilter(project),
                version = version?.let { SpecificFilter(it) } ?: AllFilter(),
                component = component?.let { SpecificFilter(it) } ?: AllFilter()
            )).sortedWith(DEFAULT_ISSUE_SORTER)

            with(http) {
                view = ProjectDetails(projectInfo, issues, version, component)
                feedPath = feedPath(project)
                navigationMenu = activeProjectNavMenu(
                    dao.listProjects(),
                    projectInfo,
                    version,
                    component
                )
                styleSheets = listOf("projects")
                render("project-details")
            }
        }
    }

    private fun projectForm(http: HttpRequest, dao: DataAccessObject) {
        val projectInfo = obtainProjectInfo(http, dao)
        if (projectInfo == null) {
            http.response.sendError(404)
            return
        }

        with(http) {
            view = ProjectEditView(projectInfo.project, dao.listUsers())
            navigationMenu = activeProjectNavMenu(
                dao.listProjects(),
                projectInfo
            )
            styleSheets = listOf("projects")
            render("project-form")
        }
    }

    private fun projectCommit(http: HttpRequest, dao: DataAccessObject) {
        // TODO: replace defaults with throwing validator exceptions
        val project = Project(http.param("id")?.toIntOrNull() ?: -1).apply {
            name = http.param("name") ?: ""
            node = http.param("node") ?: ""
            description = http.param("description") ?: ""
            ordinal = http.param("ordinal")?.toIntOrNull() ?: 0
            repoUrl = http.param("repoUrl") ?: ""
            owner = (http.param("owner")?.toIntOrNull() ?: -1).let {
                if (it < 0) null else dao.findUser(it)
            }
            // intentional defaults
            if (node.isBlank()) node = name
            // sanitizing
            node = sanitizeNode(node)
        }

        if (project.id < 0) {
            dao.insertProject(project)
        } else {
            dao.updateProject(project)
        }

        http.renderCommit("projects/${project.node}")
    }

    private fun versions(http: HttpRequest, dao: DataAccessObject) {
        val projectInfo = obtainProjectInfo(http, dao)
        if (projectInfo == null) {
            http.response.sendError(404)
            return
        }

        with(http) {
            view = VersionsView(
                projectInfo,
                dao.listVersionSummaries(projectInfo.project)
            )
            feedPath = feedPath(projectInfo.project)
            navigationMenu = activeProjectNavMenu(
                dao.listProjects(),
                projectInfo
            )
            styleSheets = listOf("projects")
            render("versions")
        }
    }

    private fun versionForm(http: HttpRequest, dao: DataAccessObject) {
        val projectInfo = obtainProjectInfo(http, dao)
        if (projectInfo == null) {
            http.response.sendError(404)
            return
        }

        val version: Version
        when (val result = http.lookupPathParam("version", projectInfo.versions)) {
            is LookupResult.NotFound -> {
                http.response.sendError(404)
                return
            }
            is LookupResult.Found -> {
                version = result.elem ?: Version(-1, projectInfo.project.id)
            }
        }

        with(http) {
            view = VersionEditView(projectInfo, version)
            feedPath = feedPath(projectInfo.project)
            navigationMenu = activeProjectNavMenu(
                dao.listProjects(),
                projectInfo,
                selectedVersion = version
            )
            styleSheets = listOf("projects")
            render("version-form")
        }
    }

    private fun versionCommit(http: HttpRequest, dao: DataAccessObject) {
        val id = http.param("id")?.toIntOrNull()
        val projectid = http.param("projectid")?.toIntOrNull() ?: -1
        val project = dao.findProject(projectid)
        if (id == null || project == null) {
            http.response.sendError(400)
            return
        }

        // TODO: replace defaults with throwing validator exceptions
        val version = Version(id, projectid).apply {
            name = http.param("name") ?: ""
            node = http.param("node") ?: ""
            ordinal = http.param("ordinal")?.toIntOrNull() ?: 0
            status = http.param("status")?.let(VersionStatus::valueOf) ?: VersionStatus.Future
            // intentional defaults
            if (node.isBlank()) node = name
            // sanitizing
            node = sanitizeNode(node)
        }

        if (id < 0) {
            dao.insertVersion(version)
        } else {
            dao.updateVersion(version)
        }

        http.renderCommit("projects/${project.node}/versions/")
    }

    private fun components(http: HttpRequest, dao: DataAccessObject) {
        val projectInfo = obtainProjectInfo(http, dao)
        if (projectInfo == null) {
            http.response.sendError(404)
            return
        }

        with(http) {
            view = ComponentsView(
                projectInfo,
                dao.listComponentSummaries(projectInfo.project)
            )
            feedPath = feedPath(projectInfo.project)
            navigationMenu = activeProjectNavMenu(
                dao.listProjects(),
                projectInfo
            )
            styleSheets = listOf("projects")
            render("components")
        }
    }

    private fun componentForm(http: HttpRequest, dao: DataAccessObject) {
        val projectInfo = obtainProjectInfo(http, dao)
        if (projectInfo == null) {
            http.response.sendError(404)
            return
        }

        val component: Component
        when (val result = http.lookupPathParam("component", projectInfo.components)) {
            is LookupResult.NotFound -> {
                http.response.sendError(404)
                return
            }
            is LookupResult.Found -> {
                component = result.elem ?: Component(-1, projectInfo.project.id)
            }
        }

        with(http) {
            view = ComponentEditView(projectInfo, component, dao.listUsers())
            feedPath = feedPath(projectInfo.project)
            navigationMenu = activeProjectNavMenu(
                dao.listProjects(),
                projectInfo,
                selectedComponent = component
            )
            styleSheets = listOf("projects")
            render("component-form")
        }
    }

    private fun componentCommit(http: HttpRequest, dao: DataAccessObject) {
        val id = http.param("id")?.toIntOrNull()
        val projectid = http.param("projectid")?.toIntOrNull() ?: -1
        val project = dao.findProject(projectid)
        if (id == null || project == null) {
            http.response.sendError(400)
            return
        }

        // TODO: replace defaults with throwing validator exceptions
        val component = Component(id, projectid).apply {
            name = http.param("name") ?: ""
            node = http.param("node") ?: ""
            ordinal = http.param("ordinal")?.toIntOrNull() ?: 0
            color = WebColor(http.param("color") ?: "#000000")
            description = http.param("description")
            lead = (http.param("lead")?.toIntOrNull() ?: -1).let {
                if (it < 0) null else dao.findUser(it)
            }
            // intentional defaults
            if (node.isBlank()) node = name
            // sanitizing
            node = sanitizeNode(node)
        }

        if (id < 0) {
            dao.insertComponent(component)
        } else {
            dao.updateComponent(component)
        }

        http.renderCommit("projects/${project.node}/components/")
    }

    private fun issue(http: HttpRequest, dao: DataAccessObject) {
        withPathInfo(http, dao)?.run {
            val issue = dao.findIssue(http.pathParams["issue"]?.toIntOrNull() ?: -1)
            if (issue == null) {
                http.response.sendError(404)
                return
            }

            val comments = dao.listComments(issue)

            with(http) {
                view = IssueDetailView(issue, comments, project, version, component)
                // TODO: feed path for this particular issue
                feedPath = feedPath(projectInfo.project)
                navigationMenu = activeProjectNavMenu(
                    dao.listProjects(),
                    projectInfo,
                    version,
                    component
                )
                styleSheets = listOf("projects")
                render("issue-view")
            }
        }
    }

    private fun issueForm(http: HttpRequest, dao: DataAccessObject) {
        withPathInfo(http, dao)?.run {
            val issue = dao.findIssue(http.pathParams["issue"]?.toIntOrNull() ?: -1) ?: Issue(
                -1,
                project,
            )

            // pre-select component, if available in the path info
            issue.component = component

            // pre-select version, if available in the path info
            if (version != null) {
                if (version.status.isReleased) {
                    issue.affectedVersions = listOf(version)
                } else {
                    issue.resolvedVersions = listOf(version)
                }
            }

            with(http) {
                view = IssueEditView(
                    issue,
                    projectInfo.versions,
                    projectInfo.components,
                    dao.listUsers(),
                    project,
                    version,
                    component
                )
                feedPath = feedPath(projectInfo.project)
                navigationMenu = activeProjectNavMenu(
                    dao.listProjects(),
                    projectInfo,
                    version,
                    component
                )
                styleSheets = listOf("projects")
                render("issue-form")
            }
        }
    }

    private fun issueComment(http: HttpRequest, dao: DataAccessObject) {
        withPathInfo(http, dao)?.run {
            val issue = dao.findIssue(http.pathParams["issue"]?.toIntOrNull() ?: -1)
            if (issue == null) {
                http.response.sendError(404)
                return
            }

            // TODO: throw validator exception instead of using a default
            val comment = IssueComment(-1, issue.id).apply {
                author = http.remoteUser?.let { dao.findUserByName(it) }
                comment = http.param("comment") ?: ""
            }

            dao.insertComment(comment)

            http.renderCommit("${issuesHref}${issue.id}")
        }
    }

    private fun issueCommit(http: HttpRequest, dao: DataAccessObject) {
        withPathInfo(http, dao)?.run {
            // TODO: throw validator exception instead of using defaults
            val issue = Issue(
                http.param("id")?.toIntOrNull() ?: -1,
                project
            ).apply {
                component = dao.findComponent(http.param("component")?.toIntOrNull() ?: -1)
                category = IssueCategory.valueOf(http.param("category") ?: "")
                status = IssueStatus.valueOf(http.param("status") ?: "")
                subject = http.param("subject") ?: ""
                description = http.param("description") ?: ""
                assignee = http.param("assignee")?.toIntOrNull()?.let {
                    when (it) {
                        -1 -> null
                        -2 -> component?.lead
                        else -> dao.findUser(it)
                    }
                }
                eta = http.param("eta")?.let { if (it.isBlank()) null else Date.valueOf(it) }

                affectedVersions = http.paramArray("affected")
                    .mapNotNull { param -> param.toIntOrNull()?.let { Version(it, project.id) } }
                resolvedVersions = http.paramArray("resolved")
                    .mapNotNull { param -> param.toIntOrNull()?.let { Version(it, project.id) } }
            }

            val openId = if (issue.id < 0) {
                dao.insertIssue(issue)
            } else {
                dao.updateIssue(issue)
                issue.id
            }

            if (http.param("more") != null) {
                http.renderCommit("${issuesHref}-/create")
            } else {
                http.renderCommit("${issuesHref}${openId}")
            }
        }
    }
}