//+----------------------------------------------------------------------------+
//| Description:  Magic Set Editor - Program to make Magic (tm) cards          |
//| Copyright:    (C) 2001 - 2008 Twan van Laarhoven and "coppro"              |
//| License:      GNU General Public License 2 or later (see file COPYING)     |
//+----------------------------------------------------------------------------+

// ----------------------------------------------------------------------------- : Includes

#include <util/prec.hpp>
#include <script/value.hpp>
#include <script/to_value.hpp>
#include <script/context.hpp>
#include <gfx/generated_image.hpp>
#include <util/error.hpp>
#include <boost/pool/singleton_pool.hpp>

DECLARE_TYPEOF_COLLECTION(pair<Variable COMMA ScriptValueP>);

// ----------------------------------------------------------------------------- : ScriptValue
// Base cases

ScriptValue::operator String()                              const { throw ScriptErrorConversion(typeName(), _TYPE_("string" )); }
ScriptValue::operator int()                                 const { throw ScriptErrorConversion(typeName(), _TYPE_("integer" )); }
ScriptValue::operator bool()                                const { throw ScriptErrorConversion(typeName(), _TYPE_("boolean" )); }
ScriptValue::operator double()                              const { throw ScriptErrorConversion(typeName(), _TYPE_("double"  )); }
ScriptValue::operator AColor()                              const { throw ScriptErrorConversion(typeName(), _TYPE_("color"   )); }
ScriptValueP ScriptValue::eval(Context&)                    const { return delay_error(ScriptErrorConversion(typeName(), _TYPE_("function"))); }
ScriptValueP ScriptValue::next(ScriptValueP* key_out)             { throw InternalError(_("Can't convert from ")+typeName()+_(" to iterator")); }
ScriptValueP ScriptValue::makeIterator(const ScriptValueP&) const { return delay_error(ScriptErrorConversion(typeName(), _TYPE_("collection"))); }
int          ScriptValue::itemCount()                       const { throw ScriptErrorConversion(typeName(), _TYPE_("collection")); }
GeneratedImageP ScriptValue::toImage(const ScriptValueP&)   const { throw ScriptErrorConversion(typeName(), _TYPE_("image"   )); }
String       ScriptValue::toCode()                          const { return *this; }
CompareWhat  ScriptValue::compareAs(String& compare_str, void const*& compare_ptr) const {
	compare_str = toCode();
	return COMPARE_AS_STRING;
}
ScriptValueP ScriptValue::getMember(const String& name) const {
	long index;
	if (name.ToLong(&index)) {
		return getIndex(index);
	} else {
		return delay_error(ScriptErrorNoMember(typeName(), name));
	}
}
ScriptValueP ScriptValue::getIndex(int index) const {
	return delay_error(ScriptErrorNoMember(typeName(), String()<<index));
}


ScriptValueP ScriptValue::simplifyClosure(ScriptClosure&) const { return ScriptValueP(); }

ScriptValueP ScriptValue::dependencyMember(const String& name, const Dependency&) const { return dependency_dummy; }
ScriptValueP ScriptValue::dependencyName(const ScriptValue& container, const Dependency& dep) const {
	return container.dependencyMember(toString(),dep);
}
ScriptValueP ScriptValue::dependencies(Context&,               const Dependency&) const { return dependency_dummy; }
void ScriptValue::dependencyThis(const Dependency& dep) {}

bool approx_equal(double a, double b) {
	return a == b || fabs(a - b) < 1e-14;
}

/// compare script values for equallity
bool equal(const ScriptValueP& a, const ScriptValueP& b) {
	if (a == b) return true;
	ScriptType at = a->type(), bt = b->type();
	if (at == bt && at == SCRIPT_INT) {
		return (int)*a == (int)*b;
	} else if (at == bt && at == SCRIPT_BOOL) {
		return (bool)*a == (bool)*b;
	} else if ((at == SCRIPT_INT || at == SCRIPT_DOUBLE) &&
	           (bt == SCRIPT_INT || bt == SCRIPT_DOUBLE)) {
		return approx_equal( (double)*a, (double)*b);
	} else if (at == SCRIPT_COLLECTION && bt == SCRIPT_COLLECTION) {
		// compare each element
		if (a->itemCount() != b->itemCount()) return false;
		ScriptValueP a_it = a->makeIterator(a);
		ScriptValueP b_it = b->makeIterator(b);
		while (true) {
			ScriptValueP a_v = a_it->next();
			ScriptValueP b_v = b_it->next();
			if (!a_v || !b_v) return a_v == b_v;
			if (!equal(a_v, b_v)) return false;
		}
	} else {
		String      as,  bs;
		const void* ap, *bp;
		CompareWhat aw = a->compareAs(as, ap);
		CompareWhat bw = b->compareAs(bs, bp);
		// compare pointers or strings
		if (aw == COMPARE_AS_STRING || bw == COMPARE_AS_STRING) {
			return as == bs;
		} else if (aw == COMPARE_AS_POINTER || bw == COMPARE_AS_POINTER) {
			return ap == bp;
		} else {
			return false;
		}
	}
}

// ----------------------------------------------------------------------------- : Errors

ScriptType ScriptDelayedError::type() const { return SCRIPT_ERROR; }

String ScriptDelayedError::typeName() const            { throw error; }
ScriptDelayedError::operator String() const            { throw error; }
ScriptDelayedError::operator double() const            { throw error; }
ScriptDelayedError::operator int()    const            { throw error; }
ScriptDelayedError::operator bool()   const            { throw error; }
ScriptDelayedError::operator AColor() const            { throw error; }
int ScriptDelayedError::itemCount() const              { throw error; }
CompareWhat ScriptDelayedError::compareAs(String&, void const*&) const { throw error; }
ScriptValueP ScriptDelayedError::getMember(const String&) const                           { return new_intrusive1<ScriptDelayedError>(error); }
ScriptValueP ScriptDelayedError::dependencyMember(const String&, const Dependency&) const { return new_intrusive1<ScriptDelayedError>(error); }
ScriptValueP ScriptDelayedError::eval(Context&) const                                     { return new_intrusive1<ScriptDelayedError>(error); }
ScriptValueP ScriptDelayedError::dependencies(Context&, const Dependency&) const          { return new_intrusive1<ScriptDelayedError>(error); }
ScriptValueP ScriptDelayedError::makeIterator(const ScriptValueP& thisP) const            { return thisP; }


// ----------------------------------------------------------------------------- : Iterators

ScriptType ScriptIterator::type() const { return SCRIPT_ITERATOR; }
String ScriptIterator::typeName() const { return _("iterator"); }
CompareWhat ScriptIterator::compareAs(String&, void const*&) const { return COMPARE_NO; }
ScriptValueP ScriptIterator::makeIterator(const ScriptValueP& thisP) const { return thisP; }

// Iterator over a range of integers
class ScriptRangeIterator : public ScriptIterator {
  public:
	// Construct a range iterator with the given bounds (inclusive)
	ScriptRangeIterator(int start, int end)
		: pos(start), start(start), end(end) {}
	virtual ScriptValueP next(ScriptValueP* key_out) {
		if (pos <= end) {
			if (key_out) *key_out = to_script(pos-start);
			return to_script(pos++);
		} else {
			return ScriptValueP();
		}
	}
  private:
	int pos, start, end;
};

ScriptValueP rangeIterator(int start, int end) {
	return new_intrusive2<ScriptRangeIterator>(start, end);
}

// ----------------------------------------------------------------------------- : Integers

#define USE_POOL_ALLOCATOR

// Integer values
class ScriptInt : public ScriptValue {
  public:
	ScriptInt(int v) : value(v) {}
	virtual ScriptType type() const { return SCRIPT_INT; }
	virtual String typeName() const { return _TYPE_("integer"); }
	virtual operator String() const { return String() << value; }
	virtual operator double() const { return value; }
	virtual operator int()    const { return value; }
  protected:
#ifdef USE_POOL_ALLOCATOR
	virtual void destroy() {
		boost::singleton_pool<ScriptValue, sizeof(ScriptInt)>::free(this);
	}
#endif
  private:
	int value;
};

#if defined(USE_POOL_ALLOCATOR) && !defined(USE_INTRUSIVE_PTR)
	// deallocation function for pool allocated integers
	void destroy_value(ScriptInt* v) {
		boost::singleton_pool<ScriptValue, sizeof(ScriptInt)>::free(v);
	}
#endif

ScriptValueP to_script(int v) {
#ifdef USE_POOL_ALLOCATOR
	#ifdef USE_INTRUSIVE_PTR
		return ScriptValueP(
				new(boost::singleton_pool<ScriptValue, sizeof(ScriptInt)>::malloc())
					ScriptInt(v));
	#else
		return ScriptValueP(
				new(boost::singleton_pool<ScriptValue, sizeof(ScriptInt)>::malloc())
					ScriptInt(v),
				destroy_value); // deallocation function
	#endif
#else
	return new_intrusive1<ScriptInt>(v);
#endif
}

// ----------------------------------------------------------------------------- : Booleans

// Boolean values
class ScriptBool : public ScriptValue {
  public:
	ScriptBool(bool v) : value(v) {}
	virtual ScriptType type() const { return SCRIPT_BOOL; }
	virtual String typeName() const { return _TYPE_("boolean"); }
	virtual operator String() const { return value ? _("true") : _("false"); }
	// bools don't autoconvert to int
	virtual operator bool()   const { return value; }
  private:
	bool value;
};

// use integers to represent true/false
/* NOTE: previous versions used ScriptInts as booleans, this gives problems
 * when we use a pool allocator for them, because the pool is destroyed before these globals.
 */
ScriptValueP script_true (new ScriptBool(true));
ScriptValueP script_false(new ScriptBool(false));


// ----------------------------------------------------------------------------- : Doubles

// Double values
class ScriptDouble : public ScriptValue {
  public:
	ScriptDouble(double v) : value(v) {}
	virtual ScriptType type() const { return SCRIPT_DOUBLE; }
	virtual String typeName() const { return _TYPE_("double"); }
	virtual operator String() const { return String() << value; }
	virtual operator double() const { return value; }
	virtual operator int()    const { return (int)value; }
  private:
	double value;
};

ScriptValueP to_script(double v) {
	return new_intrusive1<ScriptDouble>(v);
}

// ----------------------------------------------------------------------------- : String type

// String values
class ScriptString : public ScriptValue {
  public:
	ScriptString(const String& v) : value(v) {}
	virtual ScriptType type() const { return SCRIPT_STRING; }
	virtual String typeName() const { return _TYPE_("string") + _(" (\"") + (value.size() < 30 ? value : value.substr(0,30) + _("...")) + _("\")"); }
	virtual operator String() const { return value; }
	virtual operator double() const {
		double d;
		if (value.ToDouble(&d)) {
			return d;
		} else {
			throw ScriptErrorConversion(value, typeName(), _TYPE_("double"));
		}
	}
	virtual operator int()    const {
		long l;
		if (value.ToLong(&l)) {
			return l;
		} else {
			throw ScriptErrorConversion(value, typeName(), _TYPE_("integer"));
		}
	}
	virtual operator bool()   const {
		if (value == _("yes") || value == _("true")) {
			return true;
		} else if (value == _("no") || value == _("false") || value.empty()) {
			return false;
		} else {
			throw ScriptErrorConversion(value, typeName(), _TYPE_("boolean"));
		}
	}
	virtual operator AColor() const {
		AColor c = parse_acolor(value);
		if (!c.Ok()) {
			throw ScriptErrorConversion(value, typeName(), _TYPE_("color"));
		}
		return c;
	}
	virtual GeneratedImageP toImage(const ScriptValueP&) const {
		if (value.empty()) {
			return new_intrusive<BlankImage>();
		} else {
			return new_intrusive1<PackagedImage>(value);
		}
	}
	virtual int itemCount() const { return (int)value.size(); }
	virtual ScriptValueP getMember(const String& name) const {
		// get member returns characters
		long index;
		if (name.ToLong(&index) && index >= 0 && (size_t)index < value.size()) {
			return to_script(String(1,value[index]));
		} else {
			return delay_error(_ERROR_2_("has no member value", value, name));
		}
	}
  private:
	String value;
};

ScriptValueP to_script(const String& v) {
	return new_intrusive1<ScriptString>(v);
}


// ----------------------------------------------------------------------------- : Color

// AColor values
class ScriptAColor : public ScriptValue {
  public:
	ScriptAColor(const AColor& v) : value(v) {}
	virtual ScriptType type() const { return SCRIPT_COLOR; }
	virtual String typeName() const { return _TYPE_("color"); }
	virtual operator AColor() const { return value; }
	// colors don't auto convert to int, use to_int to force
	virtual operator String() const {
		return format_acolor(value);
	}
  private:
	AColor value;
};

ScriptValueP to_script(Color v) {
	return new_intrusive1<ScriptAColor>(v);
}
ScriptValueP to_script(AColor v) {
	return new_intrusive1<ScriptAColor>(v);
}


// ----------------------------------------------------------------------------- : Nil type

// the nil object
class ScriptNil : public ScriptValue {
  public:
	virtual ScriptType type() const { return SCRIPT_NIL; }
	virtual String typeName() const { return _TYPE_("nil"); }
	virtual operator String() const { return wxEmptyString; }
	virtual operator double() const { return 0.0; }
	virtual operator int()    const { return 0; }
	virtual operator bool()   const { return false; }
	virtual GeneratedImageP toImage(const ScriptValueP&) const {
		return new_intrusive<BlankImage>();
	}
	virtual ScriptValueP eval(Context& ctx) const {
		// nil(input) == input
		return ctx.getVariable(SCRIPT_VAR_input);
	}
};

/// The preallocated nil value
ScriptValueP script_nil(new ScriptNil);

// ----------------------------------------------------------------------------- : Collection base

String ScriptCollectionBase::toCode() const {
	String ret = _("[");
	bool first = true;
	#ifdef USE_INTRUSIVE_PTR
		// we can just turn this into a ScriptValueP
		// TODO: remove thisP alltogether
		ScriptValueP it = makeIterator(ScriptValueP(const_cast<ScriptValue*>(static_cast<const ScriptValue*>(this))));
	#else
		#error "makeIterator needs a ScriptValueP :("
	#endif
	while (ScriptValueP v = it->next()) {
		if (!first) ret += _(",");
		first = false;
		// todo: include keys
		ret += v->toCode();
	}
	ret += _("]");
	return ret;
}

// ----------------------------------------------------------------------------- : Custom collection

// Iterator over a custom collection
class ScriptCustomCollectionIterator : public ScriptIterator {
  public:	
	ScriptCustomCollectionIterator(ScriptCustomCollectionP col)
		: col(col), pos(0), it(col->key_value.begin()) {}
	virtual ScriptValueP next(ScriptValueP* key_out) {
		if (pos < col->value.size()) {
			if (key_out) *key_out = to_script((int)pos);
			return col->value.at(pos++);
		} else if (it != col->key_value.end()) {
			if (key_out) *key_out = to_script(it->first);
			return (it++)->second;
		} else {
			return ScriptValueP();
		}
	}
  private:
	ScriptCustomCollectionP col;
	size_t pos;
	map<String,ScriptValueP>::const_iterator it;
};

ScriptValueP ScriptCustomCollection::getMember(const String& name) const {
	map<String,ScriptValueP>::const_iterator it = key_value.find(name);
	if (it != key_value.end()) {
		return it->second;
	} else {
		return ScriptValue::getMember(name);
	}
}
ScriptValueP ScriptCustomCollection::getIndex(int index) const {
	if (index >= 0 && (size_t)index < value.size()) {
		return value.at(index);
	} else {
		return ScriptValue::getIndex(index);
	}
}
ScriptValueP ScriptCustomCollection::makeIterator(const ScriptValueP& thisP) const {
	return new_intrusive1<ScriptCustomCollectionIterator>(
	           static_pointer_cast<ScriptCustomCollection>(thisP)
	       );
}

// ----------------------------------------------------------------------------- : Concat collection

// Iterator over a concatenated collection
class ScriptConcatCollectionIterator : public ScriptIterator {
  public:	
	ScriptConcatCollectionIterator(const ScriptValueP& itA, const ScriptValueP& itB)
		: itA(itA), itB(itB) {}
	virtual ScriptValueP next(ScriptValueP* key_out) {
		if (itA) {
			ScriptValueP v = itA->next(key_out);
			if (v) return v;
			else   itA = ScriptValueP();
		}
		// TODO: somehow fix up the keys
		return itB->next(key_out);
	}
  private:
	ScriptValueP itA, itB;
};

ScriptValueP ScriptConcatCollection::getMember(const String& name) const {
	ScriptValueP member = a->getMember(name);
	if (member->type() != SCRIPT_ERROR) return member;
	long index;
	int  itemsInA = a->itemCount();
	if (name.ToLong(&index) && index - itemsInA >= 0 && index - itemsInA < b->itemCount()) { 
		// adjust integer index
		return b->getMember(String() << (index - itemsInA));
	} else {
		return b->getMember(name);
	}
}
ScriptValueP ScriptConcatCollection::getIndex(int index) const {
	int itemsInA = a->itemCount();
	if (index < itemsInA) { 
		return a->getIndex(index);
	} else {
		return b->getIndex(index - itemsInA);
	}
}
ScriptValueP ScriptConcatCollection::makeIterator(const ScriptValueP& thisP) const {
	return new_intrusive2<ScriptConcatCollectionIterator>(a->makeIterator(a), b->makeIterator(b));
}

// ----------------------------------------------------------------------------- : Default arguments / closure

ScriptType ScriptClosure::type() const {
	return SCRIPT_FUNCTION;
}
String ScriptClosure::typeName() const {
	return fun->typeName() + _(" closure");
}

void ScriptClosure::addBinding(Variable v, const ScriptValueP& value) {
	bindings.push_back(make_pair(v,value));
}
ScriptValueP ScriptClosure::getBinding(Variable v) const {
	FOR_EACH_CONST(b, bindings) {
		if (b.first == v) return b.second;
	}
	return ScriptValueP();
}

ScriptValueP ScriptClosure::simplify() {
	return fun->simplifyClosure(*this);
}

ScriptValueP ScriptClosure::eval(Context& ctx) const {
	LocalScope scope(ctx);
	applyBindings(ctx);
	return fun->eval(ctx);
}
ScriptValueP ScriptClosure::dependencies(Context& ctx, const Dependency& dep) const {
	LocalScope scope(ctx);
	applyBindings(ctx);
	return fun->dependencies(ctx, dep);
}
void ScriptClosure::applyBindings(Context& ctx) const {
	FOR_EACH_CONST(b, bindings) {
		if (ctx.getVariableScope(b.first) != 1) {
			ctx.setVariable(b.first, b.second);
		}
	}
}


ScriptType ScriptRule::type() const { return SCRIPT_FUNCTION; }
String ScriptRule::typeName() const { return fun->typeName() + _(" rule"); }
ScriptValueP ScriptRule::eval(Context& ctx) const {
	return ctx.makeClosure(fun);
}
