1 files changed, 263 insertions, 0 deletions
diff --git a/src/build_depends/dub2nix/src/dub2nix.d b/src/build_depends/dub2nix/src/dub2nix.d
new file mode 100644
index 0000000..e92ecf8
--- /dev/null
+++ b/src/build_depends/dub2nix/src/dub2nix.d
@@ -0,0 +1,263 @@
+#!/usr/bin/env dub
+/+ dub.sdl:
+    name "dub2nix"
+    stringImportPaths "."
+    dependency "vibe-d:data" version="*"
++/
+import vibe.data.json, std.string;
+
+enum mkDubNix = import("./mkDub.nix");
+enum VERSION = "0.2.4";
+enum HEADER = "# This file was generated by https://github.com/lionello/dub2nix v"~VERSION~"\n";
+
+unittest {
+    static assert(import("./dub2nix.nix").indexOf(VERSION) > 0, "VERSION does not match version in dub2nix.nix");
+}
+
+struct DubSelections {
+    int fileVersion;
+    string[string] versions;
+}
+
+struct DubRepo {
+    string owner;
+    string kind;
+    string project;
+}
+
+private string packageRegistry = "http://code.dlang.org/packages/";
+
+private auto download(string url) @trusted {
+version(none) {
+    // This works, but causes "leaking eventcore driver" warnings at shutdown
+    import vibe.http.client : requestHTTP;
+    scope res = requestHTTP();
+    return res.readJson();
+} else {
+    import std.net.curl: get, HTTP;
+    auto http = HTTP();
+    // Using deflate saves A LOT of traffic, ~40x
+    http.addRequestHeader("accept-encoding", "deflate");
+    http.addRequestHeader("accept", "application/json");
+    const data = get(url, http);
+    // Only accepting application/json, so anything else must be compressed
+    if (data[0] != '{') {
+        import std.zlib : uncompress;
+        return parseJsonString(cast(string)uncompress(data));
+    } else {
+        // parseJsonString takes immutable string, so need the .idup here
+        return parseJsonString(data.idup);
+    }
+}
+}
+
+/// Query Dub registry for the repository information of a package
+auto findRepo(string pname) @safe {
+    const url = packageRegistry ~ pname ~ ".json";
+    const json = download(url);
+    return deserializeJson!DubRepo(json["repository"]);
+}
+
+struct NixPrefetchGit {
+    @optional string type;          /// set to "git", like Go deps.nix
+    string url;                     /// URL of GIT repository
+    string rev;                     /// sha1 or tag
+    string sha256;                  /// calculated by from nix-prefetch-git
+    @optional bool fetchSubmodules; /// optional; defaults to true
+    @optional string date;          /// ignored; fetchgit doesn't actually want this
+    @optional bool deepClone;       /// ignored
+    @optional bool leaveDotGit;     /// ignored; if the .git directory should be preserved
+    @optional string path;          /// ignored; a path in the Nix store?
+}
+
+/// Invoke nix-prefetch-git and return the parsed JSON
+auto nixPrefetchGit(string url, string rev) @safe {
+    import std.process : executeShell, Config;
+    const cmd = "nix-prefetch-git --quiet " ~ url ~ " " ~ rev;
+    return deserializeJson!NixPrefetchGit(
+        executeShell(cmd, null, Config.stderrPassThrough).output
+    );
+}
+
+struct DubDep {
+    NixPrefetchGit fetch;           /// like Go deps.nix
+}
+
+/// Fetch the repo information for package `pname` and version `ver`
+auto prefetch(string pname, string ver) @safe {
+    const repo = findRepo(pname);
+    assert(repo.kind == "github");
+    const url = "https://" ~ repo.kind ~ ".com/" ~ repo.owner ~ '/' ~ repo.project ~ ".git";
+    const tag = "v" ~ ver;
+    auto set = nixPrefetchGit(url, tag);
+    // Overwrite the sha1 ref with the tag instead, so we have the version info as well
+    set.rev = tag;
+    set.type = "git";
+    return DubDep(set);
+}
+
+/// Convert D string to Nix string literal
+auto toNixString(in string s, int indent = 0) pure @safe {
+    if (s is null) {
+        return "null";
+    } else if (s.indexOfAny("\"\n") >= 0)
+        return "''\n" ~ s ~ "''";
+    else
+        return '"' ~ s ~ '"';
+}
+
+unittest {
+    static assert(toNixString(null) == "null");
+    static assert(toNixString("hello") == `"hello"`);
+    static assert(toNixString("with\nnewline") == "''\nwith\nnewline''");
+    static assert(toNixString(`with "quotes"`) == "''\nwith \"quotes\"''");
+}
+
+/// Convert D bool to Nix boolean literal
+auto toNixString(bool b, int indent = 0) pure @safe {
+    return b ? "true" : "false";
+}
+
+unittest {
+    static assert(toNixString(true) == "true");
+    static assert(toNixString(false) == "false");
+}
+
+private enum INDENT = "                                                              ";
+
+/// Convert D struct to Nix set
+auto toNixString(T)(in T pod, int indent = 0) pure @safe if (is(T == struct)) {
+    string prefix = INDENT[0..indent * 2 + 2];
+    string set = "{\n";
+    foreach(i, ref key; pod.tupleof) {
+        const id = __traits(identifier, pod.tupleof[i]);
+        set ~= prefix ~ id ~ " = " ~ toNixString(key, indent + 1) ~ ";\n";
+    }
+    return set ~ INDENT[0..indent * 2] ~ "}";
+}
+
+unittest {
+    struct TestStruct { bool b; }
+    static assert(toNixString(TestStruct.init) == "{\n  b = false;\n}");
+    static assert(toNixString(TestStruct.init, 1) == "{\n    b = false;\n  }");
+}
+
+/// Convert D AArray to Nix set
+auto toNixString(T)(in T[string] aa, int indent = 0) pure @safe {
+    string prefix = INDENT[0..indent * 2 + 2];
+    string set = "{\n";
+    foreach(id, ref key; aa) {
+        set ~= prefix ~ id ~ " = " ~ toNixString(key, indent + 1) ~ ";\n";
+    }
+    return set ~ INDENT[0..indent * 2] ~ "}";
+}
+
+unittest {
+    static assert(toNixString(["s": "x"]) == "{\n  s = \"x\";\n}");
+    static assert(toNixString(["s": ["x": true]]) == "{\n  s = {\n    x = true;\n  };\n}");
+}
+
+/// Convert D array/range to Nix list
+import std.range : isForwardRange;
+auto toNixString(R)(in R range, int indent = 0) pure @safe if (isForwardRange!R && !is(R : string)) {
+    string list = "[ ";
+    foreach(const ref item; range) {
+        list ~= toNixString(item, indent) ~ " ";
+    }
+    return list ~ "]";
+}
+
+unittest {
+    static assert(toNixString(["a"]) == `[ "a" ]`);
+}
+
+/// Create Nix expression for all dependencies in the selections JSON
+auto createNixDeps(string selectionsJson) {
+    import std.parallelism : taskPool;
+    import std.array : byPair, array;
+    import std.stdio : writeln;
+
+    const selections = deserializeJson!DubSelections(selectionsJson);
+    assert(selections.fileVersion == 1);
+
+    static auto progress(Tuple)(in Tuple pair) {
+        writeln("# Prefetching ", pair.key, "-", pair.value);
+        return prefetch(pair.key, pair.value);
+    }
+
+    // Fetch all dependency information in parallel
+    debug scope(success) writeln("# Done.");
+    return HEADER ~ toNixString(taskPool.amap!progress(selections.versions.byPair.array));
+}
+
+unittest {
+    enum json = import("./dub.selections.json");
+    enum fixture = import("./dub.selections.nix");
+    assert(createNixDeps(json) == fixture);
+}
+
+// No "main" when we're running with unittests
+version(unittest) {} else {
+
+int main(string[] args) {
+    import std.stdio : writeln;
+    import std.file : readText, write;
+    import std.getopt: getopt, defaultGetoptPrinter;
+
+    bool showVersion;
+    string input = "./dub.selections.json", deps = "./dub.selections.nix", output;
+    auto result = getopt(args,
+        "input|i|in", "Path of selections JSON; defaults to " ~ input, &input,
+        "output|o|out", "Output Nix file for Dub project.", &output,
+        "registry|r", "URL to Dub package registry; default " ~ packageRegistry, &packageRegistry,
+        "deps-file|d", "Output Nix file with dependencies; defaults to " ~ deps, &deps,
+        "version", "Show version information.", &showVersion);
+
+    if (showVersion) {
+        writeln(VERSION);
+        return 0;
+    } else if (result.helpWanted || args.length != 2 || args[1] != "save") {
+        defaultGetoptPrinter(`Usage: dub2nix [OPTIONS] COMMAND
+
+Create Nix derivations for Dub package dependencies.
+
+Commands:
+  save         Write Nix files for Dub project
+
+Options:`, result.options);
+        return 0;
+    }
+
+    try {
+        const nix = createNixDeps(readText(input));
+        if (deps == "-") {
+            writeln(nix);
+        } else {
+            write(deps, nix.representation);
+        }
+        if (output) {
+            write("mkDub.nix", mkDubNix);
+            write(output, HEADER ~ `
+{ pkgs ? import <nixpkgs> {} }:
+with import ./mkDub.nix { inherit pkgs; };
+
+mkDubDerivation {
+    src = ./.;
+    # version = "0.0.1";
+    # buildInputs = [ add any runtime deps here ];
+}
+`);
+        }
+        return 0;
+    } catch (Exception e) {
+        debug {
+            // Only dump callstack in debug builds
+            writeln(e.toString());
+        } else {
+            writeln("Error: ", e.message);
+        }
+        return 1;
+    }
+}
+
+}//!unittest