/* Compiler implementation of the D programming language
 * Copyright (C) 1999-2019 by The D Language Foundation, All Rights Reserved
 * written by Walter Bright
 * http://www.digitalmars.com
 * Distributed under the Boost Software License, Version 1.0.
 * http://www.boost.org/LICENSE_1_0.txt
 * https://github.com/D-Programming-Language/dmd/blob/master/src/json.c
 */

// This implements the JSON capability.

#include "root/dsystem.h"
#include "root/rmem.h"

#include "mars.h"
#include "dsymbol.h"
#include "template.h"
#include "aggregate.h"
#include "declaration.h"
#include "enum.h"
#include "module.h"
#include "json.h"
#include "mtype.h"
#include "attrib.h"
#include "cond.h"
#include "init.h"
#include "import.h"
#include "id.h"
#include "hdrgen.h"

class ToJsonVisitor : public Visitor
{
public:
    OutBuffer *buf;
    int indentLevel;
    const char *filename;

    ToJsonVisitor(OutBuffer *buf)
        : buf(buf), indentLevel(0), filename(NULL)
    {
    }

    void indent()
    {
        if (buf->offset >= 1 &&
            buf->data[buf->offset - 1] == '\n')
            for (int i = 0; i < indentLevel; i++)
                buf->writeByte(' ');
    }

    void removeComma()
    {
        if (buf->offset >= 2 &&
            buf->data[buf->offset - 2] == ',' &&
            (buf->data[buf->offset - 1] == '\n' || buf->data[buf->offset - 1] == ' '))
            buf->offset -= 2;
    }

    void comma()
    {
        if (indentLevel > 0)
            buf->writestring(",\n");
    }

    void stringStart()
    {
        buf->writeByte('\"');
    }

    void stringEnd()
    {
        buf->writeByte('\"');
    }

    void stringPart(const char *s)
    {
        for (; *s; s++)
        {
            utf8_t c = (utf8_t) *s;
            switch (c)
            {
                case '\n':
                    buf->writestring("\\n");
                    break;

                case '\r':
                    buf->writestring("\\r");
                    break;

                case '\t':
                    buf->writestring("\\t");
                    break;

                case '\"':
                    buf->writestring("\\\"");
                    break;

                case '\\':
                    buf->writestring("\\\\");
                    break;

                case '\b':
                    buf->writestring("\\b");
                    break;

                case '\f':
                    buf->writestring("\\f");
                    break;

                default:
                    if (c < 0x20)
                        buf->printf("\\u%04x", c);
                    else
                    {
                        // Note that UTF-8 chars pass through here just fine
                        buf->writeByte(c);
                    }
                    break;
            }
        }
    }

    // Json value functions

    /*********************************
     * Encode string into buf, and wrap it in double quotes.
     */
    void value(const char *s)
    {
        stringStart();
        stringPart(s);
        stringEnd();
    }

    void value(int value)
    {
        buf->printf("%d", value);
    }

    void valueBool(bool value)
    {
        buf->writestring(value ? "true" : "false");
    }

    /*********************************
     * Item is an intented value and a comma, for use in arrays
     */
    void item(const char *s)
    {
        indent();
        value(s);
        comma();
    }

    void item(int i)
    {
        indent();
        value(i);
        comma();
    }

    void itemBool(bool b)
    {
        indent();
        valueBool(b);
        comma();
    }


    // Json array functions

    void arrayStart()
    {
        indent();
        buf->writestring("[\n");
        indentLevel++;
    }

    void arrayEnd()
    {
        indentLevel--;
        removeComma();
        if (buf->offset >= 2 &&
            buf->data[buf->offset - 2] == '[' &&
            buf->data[buf->offset - 1] == '\n')
            buf->offset -= 1;
        else if (!(buf->offset >= 1 &&
            buf->data[buf->offset - 1] == '['))
        {
            buf->writestring("\n");
            indent();
        }
        buf->writestring("]");
        comma();
    }


    // Json object functions

    void objectStart()
    {
        indent();
        buf->writestring("{\n");
        indentLevel++;
    }

    void objectEnd()
    {
        indentLevel--;
        removeComma();
        if (buf->offset >= 2 &&
            buf->data[buf->offset - 2] == '{' &&
            buf->data[buf->offset - 1] == '\n')
            buf->offset -= 1;
        else
        {
            buf->writestring("\n");
            indent();
        }
        buf->writestring("}");
        comma();
    }

    // Json object property functions

    void propertyStart(const char *name)
    {
        indent();
        value(name);
        buf->writestring(" : ");
    }

    void property(const char *name, const char *s)
    {
        if (s == NULL) return;

        propertyStart(name);
        value(s);
        comma();
    }

    void property(const char *name, int i)
    {
        propertyStart(name);
        value(i);
        comma();
    }

    void propertyBool(const char *name, bool b)
    {
        propertyStart(name);
        valueBool(b);
        comma();
    }


    void property(const char *name, TRUST trust)
    {
        switch (trust)
        {
            case TRUSTdefault:
                // Should not be printed
                //property(name, "default");
                break;
            case TRUSTsystem:
                property(name, "system");
                break;
            case TRUSTtrusted:
                property(name, "trusted");
                break;
            case TRUSTsafe:
                property(name, "safe");
                break;
            default:
                assert(false);
        }
    }

    void property(const char *name, PURE purity)
    {
        switch (purity)
        {
            case PUREimpure:
                // Should not be printed
                //property(name, "impure");
                break;
            case PUREweak:
                property(name, "weak");
                break;
            case PUREconst:
                property(name, "const");
                break;
            case PUREstrong:
                property(name, "strong");
                break;
            case PUREfwdref:
                property(name, "fwdref");
                break;
            default:
                assert(false);
        }
    }

    void property(const char *name, LINK linkage)
    {
        switch (linkage)
        {
            case LINKdefault:
                // Should not be printed
                //property(name, "default");
                break;
            case LINKd:
                // Should not be printed
                //property(name, "d");
                break;
            case LINKc:
                property(name, "c");
                break;
            case LINKcpp:
                property(name, "cpp");
                break;
            case LINKwindows:
                property(name, "windows");
                break;
            case LINKpascal:
                property(name, "pascal");
                break;
            default:
                assert(false);
        }
    }

    void propertyStorageClass(const char *name, StorageClass stc)
    {
        stc &= STCStorageClass;
        if (stc)
        {
            propertyStart(name);
            arrayStart();

            while (stc)
            {
                const char *p = stcToChars(stc);
                assert(p);
                item(p);
            }

            arrayEnd();
        }
    }

    void property(const char *linename, const char *charname, Loc *loc)
    {
        if (loc)
        {
            const char *filename = loc->filename;
            if (filename)
            {
                if (!this->filename || strcmp(filename, this->filename))
                {
                    this->filename = filename;
                    property("file", filename);
                }
            }

            if (loc->linnum)
            {
                property(linename, loc->linnum);
                if (loc->charnum)
                    property(charname, loc->charnum);
            }
        }
    }

    void property(const char *name, Type *type)
    {
        if (type)
        {
            property(name, type->toChars());
        }
    }

    void property(const char *name, const char *deconame, Type *type)
    {
        if (type)
        {
            if (type->deco)
                property(deconame, type->deco);
            else
                property(name, type->toChars());
        }
    }

    void property(const char *name, Parameters *parameters)
    {
        if (parameters == NULL || parameters->dim == 0)
            return;

        propertyStart(name);
        arrayStart();

        if (parameters)
        {
            for (size_t i = 0; i < parameters->dim; i++)
            {
                Parameter *p = (*parameters)[i];
                objectStart();

                if (p->ident)
                    property("name", p->ident->toChars());

                property("type", "deco", p->type);

                propertyStorageClass("storageClass", p->storageClass);

                if (p->defaultArg)
                    property("default", p->defaultArg->toChars());


                objectEnd();
            }
        }

        arrayEnd();
    }

    /* ========================================================================== */

    void jsonProperties(Dsymbol *s)
    {
        if (s->isModule())
            return;

        if (!s->isTemplateDeclaration()) // TemplateDeclaration::kind() acts weird sometimes
        {
            property("name", s->toChars());
            property("kind", s->kind());
        }

        if (s->prot().kind != PROTpublic)   // TODO: How about package(names)?
            property("protection", protectionToChars(s->prot().kind));

        if (EnumMember *em = s->isEnumMember())
        {
            if (em->origValue)
                property("value", em->origValue->toChars());
        }

        property("comment", (const char *)s->comment);

        property("line", "char", &s->loc);
    }

    void jsonProperties(Declaration *d)
    {
        if (d->storage_class & STClocal)
            return;
        jsonProperties((Dsymbol *)d);

        propertyStorageClass("storageClass", d->storage_class);

        property("type", "deco", d->type);

        // Emit originalType if it differs from type
        if (d->type != d->originalType && d->originalType)
        {
            const char *ostr = d->originalType->toChars();
            if (d->type)
            {
                const char *tstr = d->type->toChars();
                if (strcmp(tstr, ostr))
                {
                    //printf("tstr = %s, ostr = %s\n", tstr, ostr);
                    property("originalType", ostr);
                }
            }
            else
                property("originalType", ostr);
        }
    }

    void jsonProperties(TemplateDeclaration *td)
    {
        jsonProperties((Dsymbol *)td);

        if (td->onemember && td->onemember->isCtorDeclaration())
            property("name", "this");  // __ctor -> this
        else
            property("name", td->ident->toChars());  // Foo(T) -> Foo
    }

    /* ========================================================================== */

    void visit(Dsymbol *)
    {
    }

    void visit(Module *s)
    {
        objectStart();

        if (s->md)
            property("name", s->md->toChars());

        property("kind", s->kind());

        filename = s->srcfile->toChars();
        property("file", filename);

        property("comment", (const char *)s->comment);

        propertyStart("members");
        arrayStart();
        for (size_t i = 0; i < s->members->dim; i++)
        {
            (*s->members)[i]->accept(this);
        }
        arrayEnd();

        objectEnd();
    }

    void visit(Import *s)
    {
        if (s->id == Id::object)
            return;

        objectStart();

        propertyStart("name");
        stringStart();
        if (s->packages && s->packages->dim)
        {
            for (size_t i = 0; i < s->packages->dim; i++)
            {
                Identifier *pid = (*s->packages)[i];
                stringPart(pid->toChars());
                buf->writeByte('.');
            }
        }
        stringPart(s->id->toChars());
        stringEnd();
        comma();

        property("kind", s->kind());
        property("comment", (const char *)s->comment);
        property("line", "char", &s->loc);
        if (s->prot().kind != PROTpublic)
            property("protection", protectionToChars(s->prot().kind));
        if (s->aliasId)
            property("alias", s->aliasId->toChars());

        bool hasRenamed = false;
        bool hasSelective = false;
        for (size_t i = 0; i < s->aliases.dim; i++)
        {
            // avoid empty "renamed" and "selective" sections
            if (hasRenamed && hasSelective)
                break;
            else if (s->aliases[i])
                hasRenamed = true;
            else
                hasSelective = true;
        }

        if (hasRenamed)
        {
            // import foo : alias1 = target1;
            propertyStart("renamed");
            objectStart();
            for (size_t i = 0; i < s->aliases.dim; i++)
            {
                Identifier *name = s->names[i];
                Identifier *alias = s->aliases[i];
                if (alias) property(alias->toChars(), name->toChars());
            }
            objectEnd();
        }

        if (hasSelective)
        {
            // import foo : target1;
            propertyStart("selective");
            arrayStart();
            for (size_t i = 0; i < s->names.dim; i++)
            {
                Identifier *name = s->names[i];
                if (!s->aliases[i]) item(name->toChars());
            }
            arrayEnd();
        }

        objectEnd();
    }

    void visit(AttribDeclaration *d)
    {
        Dsymbols *ds = d->include(NULL, NULL);

        if (ds)
        {
            for (size_t i = 0; i < ds->dim; i++)
            {
                Dsymbol *s = (*ds)[i];
                s->accept(this);
            }
        }
    }

    void visit(ConditionalDeclaration *d)
    {
        if (d->condition->inc)
        {
            visit((AttribDeclaration *)d);
        }
    }

    void visit(TypeInfoDeclaration *) {}
    void visit(PostBlitDeclaration *) {}

    void visit(Declaration *d)
    {
        objectStart();

        //property("unknown", "declaration");

        jsonProperties(d);

        objectEnd();
    }

    void visit(AggregateDeclaration *d)
    {
        objectStart();

        jsonProperties(d);

        ClassDeclaration *cd = d->isClassDeclaration();
        if (cd)
        {
            if (cd->baseClass && cd->baseClass->ident != Id::Object)
            {
                property("base", cd->baseClass->toPrettyChars(true));
            }
            if (cd->interfaces.length)
            {
                propertyStart("interfaces");
                arrayStart();
                for (size_t i = 0; i < cd->interfaces.length; i++)
                {
                    BaseClass *b = cd->interfaces.ptr[i];
                    item(b->sym->toPrettyChars(true));
                }
                arrayEnd();
            }
        }

        if (d->members)
        {
            propertyStart("members");
            arrayStart();
            for (size_t i = 0; i < d->members->dim; i++)
            {
                Dsymbol *s = (*d->members)[i];
                s->accept(this);
            }
            arrayEnd();
        }

        objectEnd();
    }

    void visit(FuncDeclaration *d)
    {
        objectStart();

        jsonProperties(d);

        TypeFunction *tf = (TypeFunction *)d->type;
        if (tf && tf->ty == Tfunction)
            property("parameters", tf->parameters);

        property("endline", "endchar", &d->endloc);

        if (d->foverrides.dim)
        {
            propertyStart("overrides");
            arrayStart();
            for (size_t i = 0; i < d->foverrides.dim; i++)
            {
                FuncDeclaration *fd = d->foverrides[i];
                item(fd->toPrettyChars());
            }
            arrayEnd();
        }

        if (d->fdrequire)
        {
            propertyStart("in");
            d->fdrequire->accept(this);
        }

        if (d->fdensure)
        {
            propertyStart("out");
            d->fdensure->accept(this);
        }

        objectEnd();
    }

    void visit(TemplateDeclaration *d)
    {
        objectStart();

        // TemplateDeclaration::kind returns the kind of its Aggregate onemember, if it is one
        property("kind", "template");

        jsonProperties(d);

        propertyStart("parameters");
        arrayStart();
        for (size_t i = 0; i < d->parameters->dim; i++)
        {
            TemplateParameter *s = (*d->parameters)[i];
            objectStart();

            property("name", s->ident->toChars());

            TemplateTypeParameter *type = s->isTemplateTypeParameter();
            if (type)
            {
                if (s->isTemplateThisParameter())
                    property("kind", "this");
                else
                    property("kind", "type");
                property("type", "deco", type->specType);

                property("default", "defaultDeco", type->defaultType);
            }

            TemplateValueParameter *value = s->isTemplateValueParameter();
            if (value)
            {
                property("kind", "value");

                property("type", "deco", value->valType);

                if (value->specValue)
                    property("specValue", value->specValue->toChars());

                if (value->defaultValue)
                    property("defaultValue", value->defaultValue->toChars());
            }

            TemplateAliasParameter *alias = s->isTemplateAliasParameter();
            if (alias)
            {
                property("kind", "alias");

                property("type", "deco", alias->specType);

                if (alias->specAlias)
                    property("specAlias", alias->specAlias->toChars());

                if (alias->defaultAlias)
                    property("defaultAlias", alias->defaultAlias->toChars());
            }

            TemplateTupleParameter *tuple = s->isTemplateTupleParameter();
            if (tuple)
            {
                property("kind", "tuple");
            }

            objectEnd();
        }
        arrayEnd();

        Expression *expression = d->constraint;
        if (expression)
        {
            property("constraint", expression->toChars());
        }

        propertyStart("members");
        arrayStart();
        for (size_t i = 0; i < d->members->dim; i++)
        {
            Dsymbol *s = (*d->members)[i];
            s->accept(this);
        }
        arrayEnd();

        objectEnd();
    }

    void visit(EnumDeclaration *d)
    {
        if (d->isAnonymous())
        {
            if (d->members)
            {
                for (size_t i = 0; i < d->members->dim; i++)
                {
                    Dsymbol *s = (*d->members)[i];
                    s->accept(this);
                }
            }
            return;
        }

        objectStart();

        jsonProperties(d);

        property("base", "baseDeco", d->memtype);

        if (d->members)
        {
            propertyStart("members");
            arrayStart();
            for (size_t i = 0; i < d->members->dim; i++)
            {
                Dsymbol *s = (*d->members)[i];
                s->accept(this);
            }
            arrayEnd();
        }

        objectEnd();
    }

    void visit(EnumMember *s)
    {
        objectStart();

        jsonProperties((Dsymbol*)s);

        property("type", "deco", s->origType);

        objectEnd();
    }

    void visit(VarDeclaration *d)
    {
        if (d->storage_class & STClocal)
            return;
        objectStart();

        jsonProperties(d);

        if (d->_init)
            property("init", d->_init->toChars());

        if (d->isField())
            property("offset", d->offset);

        if (d->alignment && d->alignment != STRUCTALIGN_DEFAULT)
            property("align", d->alignment);

        objectEnd();
    }

    void visit(TemplateMixin *d)
    {
        objectStart();

        jsonProperties(d);

        objectEnd();
    }
};


void json_generate(OutBuffer *buf, Modules *modules)
{
    ToJsonVisitor json(buf);

    json.arrayStart();
    for (size_t i = 0; i < modules->dim; i++)
    {
        Module *m = (*modules)[i];
        if (global.params.verbose)
            message("json gen %s", m->toChars());
        m->accept(&json);
    }
    json.arrayEnd();
    json.removeComma();
}