/**
Usage
=====

- In Coedit:
  the program must be located somewhere in the PATH.

- Elsewhere:
  invoke with `[-j] [<filename>]`.
  - `-j`: optional, if set then the program outputs the list (in stdout) in JSON
     otherwise in Pascal streaming text format.
  - `<filename>`: optional, the D module filename, if not set then the program
    reads the module from stdin.
  - see the source for more information about how to use the output.
    It's basically a tree of struct with 3 members: symbol type, name and location

- Test in CE as a runnable module:
  click `Compile file and run ...` and type either `<CFF>` or `-j <CFF>` in the
  input query dialog. Note that this will only work if libdparse is setup in the
  library manager.

*/
module cesyms;

import std.stdio, std.path, std.file, std.array, std.string;
import std.getopt, std.json, std.conv;
import dparse.lexer, dparse.ast, dparse.parser;
import std.traits;

enum ListFmt
{
    Pascal,
    JSON
}

void main(string[] args)
{
    // format
    bool asJson;
    getopt(args, std.getopt.config.passThrough, 'j', &asJson);

    // get either the module from stdin or from first arg
    string fname;
    ubyte[] source;
    if (args.length == 1)
    {
        version (runnable_module)
        {
            source = cast(ubyte[]) read(__FILE__, size_t.max);
        }
        else
            foreach (buff; stdin.byChunk(1024))
                source ~= buff;
    }
    else if (args.length == 2)
    {
        fname = args[$ - 1];
        if (!fname.exists)
            return;
        source = cast(ubyte[]) read(fname, size_t.max);
    }
    else
        return;

    // load and parse the file
    auto config = LexerConfig(fname, StringBehavior.source, WhitespaceBehavior.skip);
    auto scache = StringCache(StringCache.defaultBucketCount);
    auto ast = parseModule(getTokensForParser(source, config, &scache), fname,
            null, &(SymbolListBuilder.astError));

    // visit each root member
    SymbolListBuilder slb = construct!SymbolListBuilder;
    foreach (Declaration decl; ast.declarations)
    {
        slb.resetRoot;
        slb.visit(decl);
    }

    version (none)
    {
        int level = -1;
        void print(Symbol* s)
        {
            foreach (i; 0 .. level)
                write(".");
            level++;
            write(s.name, '\r');
            foreach (ss; s.subs)
                print(ss);

            level--;
        }

        print(slb.root);
    }
    else
    {
        if (asJson)
            write(slb.serializeJson);
        else
            write(slb.serializePascal);
    }

    slb.destruct;
}

// libdparse warnings includes some "'", which in Pascal are string delim
string patchPasStringLitteral(string p)
{
    import std.range : empty, front, popFront;

    string result;
    while (!p.empty)
    {
        dchar curr = p.front;
        switch (curr)
        {
        default:
            result ~= curr;
            break;
        case 10, 13:
            result ~= ' ';
            break;
        case '\'':
            result ~= "'#39'";
        }
        p.popFront;
    }
    return result;
}

// Memory utils ---------------------------------------------------------------+
void* getMem(size_t size) nothrow
{
    import std.c.stdlib;

    auto result = malloc(size);
    assert(result, "Out of memory");
    return result;
}

CT construct(CT, A...)(A a) if (is(CT == class) && !isAbstractClass!CT)
{
    auto size = typeid(CT).init.length;
    auto memory = getMem(size);
    memory[0 .. size] = typeid(CT).init[];
    static if (__traits(hasMember, CT, "__ctor"))
        (cast(CT)(memory)).__ctor(a);
    import core.memory : GC;

    GC.addRange(memory, size, typeid(CT));
    return cast(CT) memory;
}

ST* construct(ST, A...)(A a) if (is(ST == struct) || is(ST == union))
{
    import std.conv : emplace;

    auto size = ST.sizeof;
    auto memory = getMem(size)[0 .. size];
    import core.memory : GC;

    GC.addRange(memory.ptr, size, typeid(ST));
    return emplace!(ST, A)(memory, a);
}

void destruct(T)(ref T instance)
        if (is(T == class) || (isPointer!T && is(PointerTarget!T == struct)))
{
    if (!instance)
        return;
    destroy(instance);
    instance = null;
}
//----

// Serializable Symbol --------------------------------------------------------+
enum SymbolType
{
    _alias,
    _class,
    _enum,
    _error,
    _function,
    _interface,
    _import,
    _mixin, // (template decl)
    _struct,
    _template,
    _union,
    _variable,
    _warning
}

struct Symbol
{
    size_t line;
    size_t col;
    string name;
    SymbolType type;
    Symbol*[] subs;

    ~this()
    {
        foreach_reverse (i; 0 .. subs.length)
            subs[i].destruct;
    }

    void serialize(List)(auto ref List list)
    {
        static if (is(List == Appender!string))
            serializePascal(list);
        else static if (is(List == JSONValue))
            serializeJson(list);
        else
            static assert(0, "serialization kind cannot be deduced from list");
    }

    void serializePascal(ref Appender!string lfmApp)
    {
        lfmApp.put("\ritem\r");

        lfmApp.put(format("line = %d\r", line));
        lfmApp.put(format("col = %d\r", col));
        lfmApp.put(format("name = '%s'\r", name));
        lfmApp.put(format("symType = %s\r", type));

        lfmApp.put("subs = <");
        if (subs.length)
            foreach (Symbol* sub; subs)
                sub.serialize(lfmApp);
        lfmApp.put(">\r");
        lfmApp.put("end");
    }

    void serializeJson(ref JSONValue json)
    {
        auto vobj = parseJSON("{}");
        vobj["line"] = JSONValue(line);
        vobj["col"] = JSONValue(col);
        vobj["name"] = JSONValue(name);
        vobj["type"] = JSONValue(to!string(type));
        if (subs.length)
        {
            auto vsubs = parseJSON("[]");
            foreach (Symbol* sub; subs)
                sub.serializeJson(vsubs);
            vobj["items"] = vsubs;
        }
        json.array ~= vobj;
    }
}
//----

// AST visitor/Symbol list ----------------------------------------------------+
class SymbolListBuilder : ASTVisitor
{
    Symbol* root;
    Symbol* parent;

    // for some reason (?) the .name of a (static Symbol* []) item was lost
    __gshared static Symbol[] illFormed;

    size_t count;

    alias visit = ASTVisitor.visit;

    this()
    {
        root = construct!Symbol;
        resetRoot;
    }

    ~this()
    {
        root.destruct;
    }

    static void astError(string fname, size_t line, size_t col, string msg, bool isErr)
    {
        Symbol* newSym = construct!Symbol;
        newSym.col = col;
        newSym.line = line;
        newSym.name = patchPasStringLitteral(msg);
        newSym.type = isErr ? SymbolType._error : SymbolType._warning;
        illFormed ~= *newSym;
    }

    final void resetRoot()
    {
        parent = root;
    }

    final string serializePascal()
    {
        Appender!string lfmApp;
        lfmApp.reserve(count * 64);

        lfmApp.put("object TSymbolList\rsymbols = <");
        foreach (sym; illFormed)
            sym.serialize(lfmApp);
        foreach (sym; root.subs)
            sym.serialize(lfmApp);
        lfmApp.put(">\rend\r\n");

        return lfmApp.data;
    }

    final string serializeJson()
    {
        JSONValue result = parseJSON("{}");
        JSONValue vsubs = parseJSON("[]");
        foreach (sym; illFormed)
            sym.serialize(vsubs);
        foreach (sym; root.subs)
            sym.serialize(vsubs);
        result["items"] = vsubs;
        version (assert)
            return result.toPrettyString;
        // else: release mode
        else
            return result.toString;
    }

    /// visitor implementation if the declaration has a "name".
    final void namedVisitorImpl(DT, SymbolType st, bool dig = true)(const(DT) dt)
    if (__traits(hasMember, DT, "name"))
    {
        ++count;
        Symbol* newSymbol = construct!Symbol;
        newSymbol.name = dt.name.text;
        newSymbol.line = dt.name.line;
        newSymbol.col = dt.name.column;
        newSymbol.type = st;
        parent.subs ~= newSymbol;
        static if (dig)
        {
            auto previousParent = parent;
            scope (exit)
                parent = previousParent;
            parent = newSymbol;
            dt.accept(this);
        }
    }

    /// visitor implementation for special cases.
    final void otherVisitorImpl(SymbolType st, string name, size_t line, size_t col)
    {
        count++;
        Symbol* result = construct!Symbol;
        result.name = name.idup;
        result.line = line;
        result.col = col;
        result.type = st;
        parent.subs ~= result;
    }

    final override void visit(const AliasDeclaration decl)
    {
        if (decl.initializers.length)
            namedVisitorImpl!(AliasInitializer, SymbolType._alias)(decl.initializers[0]);
    }

    final override void visit(const AnonymousEnumMember decl)
    {
        namedVisitorImpl!(AnonymousEnumMember, SymbolType._enum)(decl);
    }

    final override void visit(const AnonymousEnumDeclaration decl)
    {
        decl.accept(this);
    }

    final override void visit(const AutoDeclaration decl)
    {
        if (decl.identifiers.length)
        {
            otherVisitorImpl(SymbolType._variable, decl.identifiers[0].text,
                decl.identifiers[0].line, decl.identifiers[0].column);
        }
    }

    final override void visit(const ClassDeclaration decl)
    {
        namedVisitorImpl!(ClassDeclaration, SymbolType._class)(decl);
    }

    final override void visit(const Constructor decl)
    {
        otherVisitorImpl(SymbolType._function, "this", decl.line, decl.column);
    }

    final override void visit(const Destructor decl)
    {
        otherVisitorImpl(SymbolType._function, "~this", decl.line, decl.column);
    }

    final override void visit(const EnumDeclaration decl)
    {
        namedVisitorImpl!(EnumDeclaration, SymbolType._enum)(decl);
    }

    final override void visit(const EponymousTemplateDeclaration decl)
    {
        namedVisitorImpl!(EponymousTemplateDeclaration, SymbolType._template)(decl);
    }

    final override void visit(const FunctionDeclaration decl)
    {
        namedVisitorImpl!(FunctionDeclaration, SymbolType._function)(decl);
    }

    final override void visit(const InterfaceDeclaration decl)
    {
        namedVisitorImpl!(InterfaceDeclaration, SymbolType._interface)(decl);
    }

    final override void visit(const ImportDeclaration decl)
    {
        foreach (const(SingleImport) si; decl.singleImports)
        {
            if (!si.identifierChain.identifiers.length)
                continue;

            string[] modules;
            foreach (ident; si.identifierChain.identifiers)
            {
                modules ~= ident.text;
                modules ~= ".";
            }
            otherVisitorImpl(SymbolType._import, modules[0 .. $ - 1].join,
                si.identifierChain.identifiers[0].line,
                si.identifierChain.identifiers[0].column);
        }
    }

    final override void visit(const MixinTemplateDeclaration decl)
    {
        namedVisitorImpl!(TemplateDeclaration, SymbolType._mixin)(decl.templateDeclaration);
    }

    final override void visit(const StructDeclaration decl)
    {
        namedVisitorImpl!(StructDeclaration, SymbolType._struct)(decl);
    }

    final override void visit(const TemplateDeclaration decl)
    {
        namedVisitorImpl!(TemplateDeclaration, SymbolType._template)(decl);
    }

    final override void visit(const UnionDeclaration decl)
    {
        namedVisitorImpl!(UnionDeclaration, SymbolType._union)(decl);
    }

    final override void visit(const VariableDeclaration decl)
    {
        if (decl.declarators)
            foreach (elem; decl.declarators)
                namedVisitorImpl!(Declarator, SymbolType._variable, false)(elem);
        else if (decl.autoDeclaration)
            visit(decl.autoDeclaration);
    }

    final override void visit(const StaticConstructor decl)
    {
        otherVisitorImpl(SymbolType._function, "static this", decl.line, decl.column);
    }

    final override void visit(const StaticDestructor decl)
    {
        otherVisitorImpl(SymbolType._function, "static ~this", decl.line, decl.column);
    }
}
//----