universe@179: /*
universe@179:  * Copyright 2021 Mike Becker. All rights reserved.
universe@179:  *
universe@179:  * Redistribution and use in source and binary forms, with or without
universe@179:  * modification, are permitted provided that the following conditions are met:
universe@179:  *
universe@179:  * 1. Redistributions of source code must retain the above copyright
universe@179:  * notice, this list of conditions and the following disclaimer.
universe@179:  *
universe@179:  * 2. Redistributions in binary form must reproduce the above copyright
universe@179:  * notice, this list of conditions and the following disclaimer in the
universe@179:  * documentation and/or other materials provided with the distribution.
universe@179:  *
universe@179:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@179:  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@179:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
universe@179:  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
universe@179:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
universe@179:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
universe@179:  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
universe@179:  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
universe@179:  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
universe@179:  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
universe@179:  */
universe@179: 
universe@179: package de.uapcore.lightpit
universe@179: 
universe@179: import kotlin.math.min
universe@179: 
universe@179: /**
universe@179:  * Maps requests to methods.
universe@179:  *
universe@179:  * This annotation is used to annotate methods within classes which
universe@179:  * override [AbstractServlet].
universe@179:  */
universe@179: @MustBeDocumented
universe@179: @Retention(AnnotationRetention.RUNTIME)
universe@179: @Target(AnnotationTarget.FUNCTION)
universe@179: annotation class RequestMapping(
universe@179: 
universe@179:     /**
universe@179:      * Specifies the HTTP method.
universe@179:      *
universe@179:      * @return the HTTP method handled by the annotated Java method
universe@179:      */
universe@179:     val method: HttpMethod,
universe@179: 
universe@179:     /**
universe@179:      * Specifies the request path relative to the module path.
universe@179:      * The trailing slash is important.
universe@179:      * A node may start with a dollar ($) sign.
universe@179:      * This part of the path is then treated as an path parameter.
universe@179:      * Path parameters can be obtained by including the [PathParameters] type in the signature.
universe@179:      *
universe@179:      * @return the request path the annotated method should handle
universe@179:      */
universe@179:     val requestPath: String = "/"
universe@179: )
universe@179: 
universe@179: class PathParameters : HashMap<String, String>()
universe@179: 
universe@179: /**
universe@179:  * A path pattern optionally containing placeholders.
universe@179:  *
universe@179:  * The special directories . and .. are disallowed in the pattern.
universe@179:  * Placeholders start with a $ sign.
universe@179:  *
universe@179:  * @param pattern the pattern
universe@179:  */
universe@179: class PathPattern(pattern: String) {
universe@179:     private val nodePatterns: List<String>
universe@179:     private val collection: Boolean
universe@179: 
universe@179:     private fun parse(pattern: String): List<String> {
universe@179:         val nodes = pattern.split("/").filter { it.isNotBlank() }.toList()
universe@179:         require(nodes.none { it == "." || it == ".." }) { "Path must not contain '.' or '..' nodes." }
universe@179:         return nodes
universe@179:     }
universe@179: 
universe@179:     /**
universe@179:      * Matches a path against this pattern.
universe@179:      * The path must be canonical in the sense that no . or .. parts occur.
universe@179:      *
universe@179:      * @param path the path to match
universe@179:      * @return true if the path matches the pattern, false otherwise
universe@179:      */
universe@179:     fun matches(path: String): Boolean {
universe@179:         if (collection xor path.endsWith("/")) return false
universe@179:         val nodes = parse(path)
universe@179:         if (nodePatterns.size != nodes.size) return false
universe@179:         for (i in nodePatterns.indices) {
universe@179:             val pattern = nodePatterns[i]
universe@179:             val node = nodes[i]
universe@179:             if (pattern.startsWith("$")) continue
universe@179:             if (pattern != node) return false
universe@179:         }
universe@179:         return true
universe@179:     }
universe@179: 
universe@179:     /**
universe@179:      * Returns the path parameters found in the specified path using this pattern.
universe@179:      * The return value of this method is undefined, if the patter does not match.
universe@179:      *
universe@179:      * @param path the path
universe@179:      * @return the path parameters, if any, or an empty map
universe@179:      * @see .matches
universe@179:      */
universe@179:     fun obtainPathParameters(path: String): PathParameters {
universe@179:         val params = PathParameters()
universe@179:         val nodes = parse(path)
universe@179:         for (i in 0 until min(nodes.size, nodePatterns.size)) {
universe@179:             val pattern = nodePatterns[i]
universe@179:             val node = nodes[i]
universe@179:             if (pattern.startsWith("$")) {
universe@179:                 params[pattern.substring(1)] = node
universe@179:             }
universe@179:         }
universe@179:         return params
universe@179:     }
universe@179: 
universe@179:     override fun hashCode(): Int {
universe@179:         val str = StringBuilder()
universe@179:         for (node in nodePatterns) {
universe@179:             if (node.startsWith("$")) {
universe@179:                 str.append("/$")
universe@179:             } else {
universe@179:                 str.append('/')
universe@179:                 str.append(node)
universe@179:             }
universe@179:         }
universe@179:         if (collection) str.append('/')
universe@179:         return str.toString().hashCode()
universe@179:     }
universe@179: 
universe@179:     override fun equals(other: Any?): Boolean {
universe@179:         if (other is PathPattern) {
universe@179:             if (collection xor other.collection || nodePatterns.size != other.nodePatterns.size) return false
universe@179:             for (i in nodePatterns.indices) {
universe@179:                 val left = nodePatterns[i]
universe@179:                 val right = other.nodePatterns[i]
universe@179:                 if (left.startsWith("$") && right.startsWith("$")) continue
universe@179:                 if (left != right) return false
universe@179:             }
universe@179:             return true
universe@179:         } else {
universe@179:             return false
universe@179:         }
universe@179:     }
universe@179: 
universe@179:     init {
universe@179:         nodePatterns = parse(pattern)
universe@179:         collection = pattern.endsWith("/")
universe@179:     }
universe@179: }
universe@179: