(ns leiningen.core.eval
  "Evaluate code inside the context of a project."
  (:require [classlojure.core :as cl]
            [clojure.java.io :as io]
            [clojure.string :as string]
            [cemerick.pomegranate.aether :as aether]
            [leiningen.core.project :as project]
            [leiningen.core.main :as main]
            [leiningen.core.classpath :as classpath]
            [leiningen.core.utils :as utils])
  (:import (com.hypirion.io Pipe ClosingPipe)
           (java.io File)))

(def ^:private arch-options
  {:x86 ["-d32"] :x86_64 ["-d64"]})

(def ^:deprecated get-os
  "Returns a keyword naming the host OS. Deprecated, use
  leiningen.core.utils/get-os instead."
  utils/get-os)

(def ^:deprecated get-arch
  "Returns a keyword naming the host architecture. Deprecated, use
  leiningen.core.utils/get-arch instead."
  utils/get-arch)

(def ^:deprecated platform-nullsink
  "Returns a file destination that will discard output.  Deprecated, use
  leiningen.core.utils/platform-nullsink instead."
  utils/platform-nullsink)

(def ^:dynamic *eval-print-dup* false)

;; # Preparing for eval-in-project

(defn- write-pom-properties [{:keys [compile-path group name] :as project}]
  (when (and (:root project) (:write-pom-properties project true))
    (let [path (format "%s/META-INF/maven/%s/%s/pom.properties"
                       (or compile-path "target/classes") group name)]
      (utils/mkdirs (.getParentFile (io/file path)))
      (spit path (project/make-project-properties project)))))

(defn run-prep-tasks
  "Execute all the prep-tasks. A task can either be a string, or a
  vector if it takes arguments. see :prep-tasks in sample.project.clj
  for examples"
  [{:keys [prep-tasks] :as project}]
  (doseq [task prep-tasks]
    (let [[task-name & task-args] (if (vector? task) task [task])
          task-name (main/lookup-alias task-name project)]
      (main/apply-task task-name (dissoc project :prep-tasks) task-args))))

;; Some tasks
(defonce ^{:doc "Block on this to wait till the project is fully prepped."}
  prep-blocker (atom (promise)))

(defn- remove-default-paths
  ;; Hack to get around #2010. I'm sorry =(
  ;; We track down metadata keys on the form :default-path/foo, then absolutize
  ;; foo and remove it from the list ONCE if we see it.
  [project paths]
  (let [paths-to-remove (for [k (keys (meta paths))
                              :when (and (keyword? k)
                                         (= "default-path" (namespace k)))]
                          (str (io/file (:root project) (name k))))]
    (loop [acc []
           to-remove (set paths-to-remove)
           [fst & rst :as ps] paths]
      (cond (not (seq ps)) acc
            (to-remove fst) (recur acc (disj to-remove fst) rst)
            :else (recur (conj acc fst) to-remove rst)))))

(defn prep
  "Before we can run eval-in-project we need to prep the project by running
  javac, compile, and any other tasks the project specifies."
  [project]
  ;; These must exist before the project is launched.
  (when (:root project)
    (utils/mkdirs (io/file (:compile-path project "/tmp")))
    ;; hack to not create default projects. For now only.
    (doseq [path (mapcat #(remove-default-paths project %)
                         ((juxt :source-paths :test-paths :resource-paths) project))]
      (utils/mkdirs (io/file path))))
  (write-pom-properties project)
  (classpath/resolve-managed-dependencies :dependencies :managed-dependencies project)
  (run-prep-tasks project)
  (deliver @prep-blocker true)
  (reset! prep-blocker (promise)))

;; # Subprocess stuff

(defn native-arch-paths
  "Paths to the os/arch-specific directory containing native libs."
  [project]
  (let [os (:os project (utils/get-os))
        arch (:arch project (utils/get-arch))
        native-path (:native-path project)]
    (if (and os arch)
      (conj
       (->> (:dependencies project)
            (map classpath/get-native-prefix)
            (remove nil?)
            (map #(io/file native-path %)))
       (io/file native-path (name os) (name arch))))))

(defn- as-str [x]
  (if (instance? clojure.lang.Named x)
    (name x)
    (str x)))

(defn- d-property [[k v]]
  (format "-D%s=%s" (as-str k) v))

(defn ^:internal get-jvm-opts-from-env [env-opts]
  (and (seq env-opts)
       (re-seq #"(?:[^\s\"']+|\"[^\"]*\"|'[^']*')+" (string/trim env-opts))))

(defn- get-jvm-args
  "Calculate command-line arguments for launching java subprocess."
  [project]
  (let [native-arch-paths (native-arch-paths project)]
    `(~(d-property [:file.encoding (or (System/getProperty "file.encoding") "UTF-8")])
      ~@(get-jvm-opts-from-env (System/getenv "JVM_OPTS"))
      ~@(:jvm-opts project)
      ~@(get arch-options (:arch project))
      ;; TODO: support -Xverify:none
      ~@(map d-property {:clojure.compile.path (:compile-path project)
                         (str (:name project) ".version") (:version project)
                         :clojure.debug (boolean (or (System/getenv "DEBUG")
                                                     (:debug project)))})
      ~@(if native-arch-paths
          (let [extant-paths (filter #(.exists %) native-arch-paths)]
            (if (seq extant-paths)
              [(d-property [:java.library.path
                            (string/join java.io.File/pathSeparatorChar
                                         extant-paths)])])))
      ~@(when-let [{:keys [host port non-proxy-hosts]} (classpath/get-proxy-settings)]
          [(d-property [:http.proxyHost host])
           (d-property [:http.proxyPort port])
           (d-property [:http.nonProxyHosts non-proxy-hosts])])
      ~@(when-let [{:keys [host port]} (classpath/get-proxy-settings "https_proxy")]
          [(d-property [:https.proxyHost host])
           (d-property [:https.proxyPort port])]))))

(def ^:dynamic *dir*
  "Directory in which to start subprocesses with eval-in-project or sh."
  (System/getProperty "user.dir"))

(def ^:dynamic *env*
  "Environment map with which to start subprocesses with eval-in-project or sh.
  Merged into the current environment unless ^:replace metadata is attached."
  nil)

(def ^:dynamic *pump-in*
  "Rebind this to false to disable forwarding *in* to subprocesses."
  true)

(def drip-env
  {"DRIP_INIT" nil
   "DRIP_INIT_CLASS" nil})

(defn- overridden-env
  "Returns an overridden version of the current environment as an Array of
  Strings of the form name=val, suitable for passing to Runtime#exec."
  [env]
  (->> (if (:replace (meta env))
         env
         (merge {} (System/getenv) drip-env env))
       (filter val)
       (map #(str (name (key %)) "=" (val %)))
       (into-array String)))

(defn sh ;; TODO 3.0.0 - move to independent namespace. e.g. io.clj
  "A version of clojure.java.shell/sh that streams in/out/err."
  [& cmd]
  (when *pump-in*
    (utils/rebind-io!))
  (let [env (overridden-env *env*)
        proc (.exec (Runtime/getRuntime) (into-array String cmd) env (io/file *dir*))]
    (.addShutdownHook (Runtime/getRuntime)
                      (Thread. (fn [] (.destroy proc))))
    (with-open [out (.getInputStream proc)
                err (.getErrorStream proc)
                in (.getOutputStream proc)]
      (let [pump-out (doto (Pipe. out System/out) .start)
            pump-err (doto (Pipe. err System/err) .start)
            ;; TODO: this prevents nrepl need-input msgs from being propagated
            ;; in the case of connecting to Leiningen over nREPL.
            pump-in (ClosingPipe. System/in in)]
        (when *pump-in* (.start pump-in))
        (.join pump-out)
        (.join pump-err)
        (let [exit-value (.waitFor proc)]
          (when *pump-in*
            (.kill System/in)
            (.join pump-in)
            (.resurrect System/in))
          exit-value)))))

(defn sh-with-exit-code
  "Applies SH to CMD and on a non-0 exit code, throws an Exception
  using FAILURE-MESSAGE. A period is appended to FAILURE-MESSAGE.
  Returns the exit code on success.

  FAILURE-MESSAGE must satisfy `string?`.
  (first CMD) must satisfy `string?`."
  [failure-message & cmd]
  {:pre [(string? failure-message)
         (string? (first cmd))]}
  (let [exit-code (apply sh cmd)]
    (when-not (= 0 exit-code)
      (throw (Exception. (format "%s. %s exit code: %d" failure-message (first cmd) exit-code))))
    exit-code))

(defn- agent-arg [coords file]
  (let [{:keys [options bootclasspath]} (apply hash-map coords)]
    (concat [(str "-javaagent:" file (and options (str "=" options)))]
            (if bootclasspath [(str "-Xbootclasspath/a:" file)]))))

(defn ^:internal classpath-arg [project]
  (let [classpath-string (string/join java.io.File/pathSeparatorChar
                                      (classpath/get-classpath project))
        agent-tree (classpath/get-dependencies :java-agents nil project)
        ;; Seems like you'd expect dependency-files to walk the whole tree
        ;; here, but it doesn't, which is what we want. but maybe a bug?
        agent-jars (aether/dependency-files (aether/dependency-hierarchy
                                             (:java-agents project) agent-tree))]
    `(~@(mapcat agent-arg (:java-agents project) agent-jars)
      ~@(if (:bootclasspath project)
          [(str "-Xbootclasspath/a:" classpath-string)]
          ["-classpath" classpath-string]))))

(defn shell-command
  "Calculate vector of strings needed to evaluate form in a project subprocess."
  [project form]
  (let [checksum (System/getProperty "leiningen.input-checksum")
        init-file (if (empty? checksum)
                    (File/createTempFile "form-init" ".clj")
                    (io/file (:target-path project) (str checksum "-init.clj")))]
    (spit init-file
          (binding [*print-dup* *eval-print-dup*]
            (pr-str (when-not (System/getenv "LEIN_FAST_TRAMPOLINE")
                      `(.deleteOnExit (File. ~(.getCanonicalPath init-file))))
                    form)))
    `(~(or (:java-cmd project) (System/getenv "JAVA_CMD") "java")
      ~@(classpath-arg project)
      ~@(get-jvm-args project)
      "clojure.main" "-i" ~(.getCanonicalPath init-file))))

;; # eval-in multimethod

(defmulti eval-in
  "Evaluate the given form in various contexts."
  ;; Force it to be a keyword so that we can accept symbols too. That
  ;; way ^:replace and ^:displace metadata can be applied.
  (fn [project _] (keyword (name (:eval-in project :default)))))

(defmethod eval-in :default [project form]
  (eval-in (assoc project :eval-in :subprocess) form))

(defmethod eval-in :subprocess [project form]
  (binding [*dir* (:root project)]
    (let [exit-code (apply sh (shell-command project form))]
      (when (pos? exit-code)
        (throw (ex-info "Subprocess failed" {:exit-code exit-code}))))))

(defonce trampoline-project (atom nil))
(defonce trampoline-forms (atom []))
(defonce trampoline-profiles (atom []))

(defmethod eval-in :trampoline [project form]
  (reset! trampoline-project project)
  (swap! trampoline-forms conj form)
  (swap! trampoline-profiles conj (select-keys project
                                               [:dependencies :source-paths
                                                :resource-paths :test-paths])))

(defmethod eval-in :classloader [project form]
  (when-let [classpath (map io/file (classpath/ext-classpath project))]
    (cl/wrap-ext-classloader classpath))
  (let [classpath   (map io/file (classpath/get-classpath project))
        classloader (cl/classlojure classpath)]
    (doseq [opt (get-jvm-args project)
            :when (.startsWith opt "-D")
            :let [[_ k v] (re-find #"^-D(.*?)=(.*)$" opt)]]
      (if (= k "java.library.path")
        (cl/alter-java-library-path!
         (constantly (string/split v (re-pattern java.io.File/pathSeparator))))
        (System/setProperty k v)))
    (try (cl/eval-in classloader form)
         (catch Exception e
           (println (str "Error evaluating in classloader: "
                         (class e) ":" (.getMessage e)))
           (.printStackTrace e)
           (throw (ex-info "Classloader eval failed" {:exit-code 1}))))))

(defn- send-input [message client session pending]
  (let [id (str (java.util.UUID/randomUUID))]
    (swap! pending conj id)
    (message client {:id id :op "stdin" :stdin (str (read-line) "\n")
                     :session session})))

(defn- done? [{:keys [id status] :as msg} pending]
  (let [pending? (@pending id)]
    (swap! pending disj id)
    (and (not pending?) (some #{"done" "interrupted" "error"} status))))

(defmethod eval-in :nrepl [project form]
  (require 'nrepl.core)
  (let [port-file (io/file (:target-path project) "repl-port")
        connect (resolve 'nrepl/connect)
        client (resolve 'nrepl/client)
        client-session (resolve 'nrepl/client-session)
        message (resolve 'nrepl/message)
        recv (resolve 'nrepl.transport/recv)]
    (if (.exists port-file)
      (let [transport (connect :host "localhost"
                               :port (Integer. (slurp port-file)))
            client (client-session (client transport Long/MAX_VALUE))
            pending (atom #{})]
        (message client {:op "eval" :code (binding [*print-dup* *eval-print-dup*]
                                            (pr-str form))})
        (doseq [{:keys [out err status session] :as msg} (repeatedly
                                                          #(recv transport 100))
                :while (not (done? msg pending))]
          (when out (print out) (flush))
          (when err (binding [*out* *err*] (print err) (flush)))
          (when (some #{"need-input"} status)
            (send-input message client session pending))))
      ;; TODO: warn that repl couldn't be used?
      (eval-in (assoc project :eval-in :subprocess) form))))

(defmethod eval-in :leiningen [project form]
  (when (:debug project)
    (System/setProperty "clojure.debug" "true"))
  ;; :dependencies are loaded the same way as plugins in eval-in-leiningen
  (project/load-plugins project :dependencies :managed-dependencies)
  (project/init-lein-classpath project)
  (doseq [opt (get-jvm-args project)
          :when (.startsWith opt "-D")
          :let [[_ k v] (re-find #"^-D(.*?)=(.*)$" opt)]]
    (System/setProperty k v))
  (eval form))

(defmethod eval-in :pprint [project form]
  (require 'clojure.pprint)
  (println "Java:" (or (:java-cmd project) (System/getenv "JAVA_CMD") "java"))
  (apply println "Classpath:" (classpath-arg project))
  (apply println "JVM args:" (get-jvm-args project))
  ;; Can't use binding with dynamic require
  (let [dispatch-var (resolve 'clojure.pprint/*print-pprint-dispatch*)
        code-dispatch @(resolve 'clojure.pprint/code-dispatch)]
    (try (push-thread-bindings {dispatch-var code-dispatch})
         ((resolve 'clojure.pprint/pprint) form)
         (finally (pop-thread-bindings)))))

(defn eval-in-project
  "Executes form in isolation with the classpath and compile path set correctly
  for the project. If the form depends on any requires, put them in the init arg
  to avoid the Gilardi Scenario: http://technomancy.us/143"
  ([project form] (eval-in-project project form nil))
  ([project form init]
     (prep project)
     (when (:warn-on-reflection project)
       (main/warn "WARNING: :warn-on-reflection is deprecated in project.clj;"
                  "use :global-vars."))
     (eval-in project
              `(do (set! ~'*warn-on-reflection*
                         ~(:warn-on-reflection project))
                   ~@(map (fn [[k v]] `(set! ~k ~v)) (:global-vars project))
                   ~init
                   ~@(:injections project)
                   ~form))))
