#include <stdint.h>
#include <string.h>

#include <llvm-c/Analysis.h>
#include <llvm-c/Core.h>
#include <llvm-c/ExecutionEngine.h>

#include "alloc.h"
#include "analyzer.h"
#include "common.h"
#include "errors.h"
#include "strview.h"

#define lengthof(xs) (sizeof(xs) / sizeof(*(xs)))

/* A context structure we can pass to all the codegen functions just so they
   have easy access to everything */
struct cgctx {
	arena a;
	LLVMContextRef ctx;
	LLVMModuleRef mod;
	LLVMBuilderRef bob;
	struct strview namespace;
};

static LLVMTypeRef type2llvm(struct cgctx, struct type);

void
codegen(const char *file, struct type *types, struct ast ast,
        struct lexemes toks)
{
	char *triple = LLVMGetDefaultTargetTriple();

	struct cgctx ctx;
	ctx.a           = NULL;
	ctx.namespace.p = NULL;
	ctx.ctx         = LLVMContextCreate();
	ctx.mod         = LLVMModuleCreateWithNameInContext("oryx", ctx.ctx);
	ctx.bob         = LLVMCreateBuilderInContext(ctx.ctx);
	LLVMSetSourceFileName(ctx.mod, file, strlen(file));
	LLVMSetTarget(ctx.mod, triple);
	LLVMDisposeMessage(triple);

	arena_free(&ctx.a);

	LLVMDisposeBuilder(ctx.bob);

	char *error = NULL;
	if (LLVMVerifyModule(ctx.mod, LLVMReturnStatusAction, &error) == 1)
		err("codegen: %s", error);

	LLVMDumpModule(ctx.mod);
	LLVMDisposeModule(ctx.mod);
	LLVMContextDispose(ctx.ctx);
}

LLVMTypeRef
type2llvm(struct cgctx ctx, struct type t)
{
	switch (t.kind) {
	case TYPE_FN:
		err("codegen: %s: Not implemented for function types", __func__);
	case TYPE_NUM:
		/* TODO: Floats */
		if (t.isfloat)
			err("codegen: %s: Not implemented for floats", __func__);
		/* TODO: Arbitrary precision */
		if (t.size == 0)
			return LLVMInt64TypeInContext(ctx.ctx);
		assert((unsigned)t.size * 8 <= UINT8_MAX);
		return LLVMIntTypeInContext(ctx.ctx, t.size * 8);
	default:
		__builtin_unreachable();
	}
}