#include <bshell/command/alias.h>
#include <bshell/command/command.h>
#include <bshell/command/native-command.h>
#include <bshell/runtime/cmdcall.h>
#include <bshell/runtime/pipeline.h>
#include <bshell/runtime/runtime.h>
#include <bshell/status.h>
#include <fx/collections/array.h>
#include <fx/collections/hashtable.h>
#include <fx/io/path.h>
#include <fx/reflection/assembly.h>
#include <fx/reflection/function.h>
#include <fx/reflection/type.h>
#include <fx/string.h>
#include <fx/vector.h>

#if BSHELL_ENABLE_NATIVE_COMMANDS == 1
#include <fx/diagnostics/process.h>
#endif

#if BSHELL_INTERACTIVE == 1
#include <fx/term/print.h>
#endif

enum cmdcall_type {
	CMDCALL_NONE = 0,
	CMDCALL_CMDLET,
	CMDCALL_NATIVE,
};

struct bshell_cmdcall_p {
	enum cmdcall_type cmd_type;
	bshell_command *cmd_target;
	char *cmd_native_path;
	bool cmd_initialised;
	FX_VECTOR_DECLARE(fx_value, cmd_args);
	fx_array *cmd_args_processed;
};

static void cmdcall_fini(fx_object *obj, void *priv)
{
	struct bshell_cmdcall_p *cmdcall = priv;

	if (cmdcall->cmd_target) {
		bshell_command_end_processing(cmdcall->cmd_target);
		bshell_command_unref(cmdcall->cmd_target);
	}

	if (cmdcall->cmd_native_path) {
		free(cmdcall->cmd_native_path);
	}

	if (cmdcall->cmd_args_processed) {
		fx_array_unref(cmdcall->cmd_args_processed);
	}

	for (size_t i = 0; i < cmdcall->cmd_args.count; i++) {
		fx_value_unset(&cmdcall->cmd_args.items[i]);
	}

	fx_vector_destroy(cmdcall->cmd_args, NULL);
}

static enum bshell_status cmdcall_push_arg(
	struct bshell_cmdcall_p *cmdcall,
	fx_value arg)
{
	fx_value *slot = fx_vector_emplace_back(cmdcall->cmd_args, NULL);
	fx_value_copy(slot, &arg);

	return BSHELL_SUCCESS;
}

static const fx_value *get_arg(struct bshell_cmdcall_p *cmdcall, size_t index)
{
	if (index >= cmdcall->cmd_args.count) {
		return NULL;
	}

	return &cmdcall->cmd_args.items[cmdcall->cmd_args.count - index - 1];
}

static bshell_command *resolve_cmdlet(
	struct bshell_cmdcall_p *cmdcall,
	struct bshell_runtime *rt,
	fx_string *cmd_name)
{
	while (1) {
		const char *cmd_name_cstr = fx_string_get_cstr(cmd_name);
		bshell_command *cmd
			= bshell_runtime_find_command(rt, cmd_name_cstr);
		if (!cmd) {
			break;
		}

		bshell_alias_class *alias
			= fx_object_get_interface(cmd, BSHELL_TYPE_ALIAS);
		if (alias) {
			fx_string_clear(cmd_name);
			fx_string_append_cstr(cmd_name, alias->a_target_name);
			bshell_command_unref(cmd);
			continue;
		}

		return cmd;
	}

	return NULL;
}

static const fx_string *get_path(void)
{
#if BSHELL_ENABLE_NATIVE_COMMANDS == 1
	fx_process *self = fx_process_get_self();
	if (!self) {
		return NULL;
	}

	const fx_hashtable *env = fx_process_get_environment(self);
	if (!env) {
		return NULL;
	}

	const fx_value *path_v = fx_hashtable_get(env, &FX_CSTR("PATH"));
	if (!path_v) {
		return NULL;
	}

	const fx_string *path = NULL;
	fx_value_get_object(path_v, (fx_object **)&path);
	return path;
#else
	return NULL;
#endif
}

#if BSHELL_ENABLE_NATIVE_COMMANDS == 1
static bshell_command *resolve_native_command_local(
	struct bshell_cmdcall_p *cmdcall,
	struct bshell_runtime *rt,
	fx_string *cmd_name)
{
	const char *cmd_name_cstr = fx_string_get_cstr(cmd_name);
	fx_path *cmd_path = fx_path_create_from_cstr(cmd_name_cstr);
	if (!fx_path_is_file(cmd_path)) {
		fx_path_unref(cmd_path);
		return NULL;
	}

	bshell_command *result
		= bshell_native_command_create(fx_path_get_cstr(cmd_path));
	fx_path_unref(cmd_path);
	return result;
}

static bshell_command *resolve_native_command(
	struct bshell_cmdcall_p *cmdcall,
	struct bshell_runtime *rt,
	fx_string *cmd_name)
{
	const char *cmd_name_cstr = fx_string_get_cstr(cmd_name);
	if (cmd_name_cstr[0] == '/'
	    || (cmd_name_cstr[0] == '.' && cmd_name_cstr[1] == '/')
	    || (cmd_name_cstr[0] == '.' && cmd_name_cstr[1] == '.'
	        && cmd_name_cstr[2] == '/')) {
		return resolve_native_command_local(cmdcall, rt, cmd_name);
	}

	fx_path *cmd_name_path = fx_path_create_from_cstr(cmd_name_cstr);
	const char *delim[] = {":"};
	const fx_string *path = get_path();
	const fx_iterator *it = fx_string_tokenise(
		path,
		delim,
		sizeof delim / sizeof delim[0],
		FX_STRING_TOK_F_NORMAL);
	bshell_command *result = NULL;

	fx_foreach(v, it)
	{
		const char *tok = NULL;

		fx_path *full_path
			= fx_path_join_list(2, v, &FX_VALUE_OBJECT(cmd_name));
		if (!fx_path_is_file(full_path)) {
			fx_path_unref(full_path);
			continue;
		}

		result = bshell_native_command_create(
			fx_path_get_cstr(full_path));
		fx_path_unref(full_path);
		break;
	}

	fx_iterator_unref(it);
	return result;
}
#endif

static enum bshell_status resolve_call_target(
	struct bshell_cmdcall_p *cmdcall,
	struct bshell_runtime *rt)
{
	fx_value *cmd_name_v = fx_array_get_ref(cmdcall->cmd_args_processed, 0);
	if (!cmd_name_v) {
		return BSHELL_ERR_BAD_STATE;
	}

	fx_string *cmd_name_s = NULL;
	fx_value_get_object(cmd_name_v, &cmd_name_s);

	if ((cmdcall->cmd_target = resolve_cmdlet(cmdcall, rt, cmd_name_s))) {
		cmdcall->cmd_type = CMDCALL_CMDLET;
		return BSHELL_SUCCESS;
	}

#if BSHELL_ENABLE_NATIVE_COMMANDS == 1
	if ((cmdcall->cmd_target
	     = resolve_native_command(cmdcall, rt, cmd_name_s))) {
		cmdcall->cmd_type = CMDCALL_NATIVE;
		return BSHELL_SUCCESS;
	}
#endif

	const char *cmd_name_cstr = fx_string_get_cstr(cmd_name_s);
#if BSHELL_INTERACTIVE == 1
	fx_printf("[bold,bright_red]");
#endif
	printf("%s: The term '%s' is not recognised as a name of a cmdlet, "
	       "function, script file, or executable program.\n",
	       cmd_name_cstr,
	       cmd_name_cstr);
#if BSHELL_INTERACTIVE == 1
	fx_printf("[reset]");
#endif
	printf("\n");
	return BSHELL_ERR_NO_ENTRY;
}

static enum bshell_status process_args(struct bshell_cmdcall_p *cmdcall)
{
	if (cmdcall->cmd_args_processed) {
		return BSHELL_SUCCESS;
	}

	fx_stringstream *str = fx_stringstream_create();
	if (!str) {
		return BSHELL_ERR_NO_MEMORY;
	}

	cmdcall->cmd_args_processed = fx_array_create();
	if (!cmdcall->cmd_args_processed) {
		fx_stringstream_unref(str);
		return BSHELL_ERR_NO_MEMORY;
	}

	for (i32 i = cmdcall->cmd_args.count - 1; i >= 0; i--) {
		fx_stringstream_reset(str);
		fx_value_to_string(&cmdcall->cmd_args.items[i], str, NULL);
		fx_string *arg_str = fx_string_create_from_cstr(
			fx_stringstream_get_cstr(str));
		fx_array_push_back(
			cmdcall->cmd_args_processed,
			FX_VALUE_OBJECT(arg_str));
		fx_string_unref(arg_str);
	}

	fx_stringstream_unref(str);
	return BSHELL_SUCCESS;
}

static enum bshell_status cmdcall_resolve(
	struct bshell_cmdcall_p *cmdcall,
	struct bshell_runtime *rt)
{
	enum bshell_status status = process_args(cmdcall);
	if (status != BSHELL_SUCCESS) {
		return status;
	}

	status = resolve_call_target(cmdcall, rt);
	if (status != BSHELL_SUCCESS) {
		return status;
	}

	bshell_command_set_args_reverse(
		cmdcall->cmd_target,
		cmdcall->cmd_args.items,
		cmdcall->cmd_args.count);

	return BSHELL_SUCCESS;
}

static enum bshell_status cmdcall_execute(struct bshell_cmdcall_p *cmdcall)
{
	return BSHELL_SUCCESS;
}

static enum bshell_status cmdcall_process_record(
	struct bshell_cmdcall_p *cmdcall,
	bshell_pipeline *pipeline,
	struct bshell_runtime *rt,
	enum bshell_command_position position)
{
	if (!cmdcall->cmd_target) {
		return BSHELL_ERR_NOT_SUPPORTED;
	}

	if (!cmdcall->cmd_initialised) {
		bshell_command_begin_processing(cmdcall->cmd_target, position);
		cmdcall->cmd_initialised = true;
	}

	return bshell_command_process_record(cmdcall->cmd_target, pipeline, rt);
}

enum bshell_status bshell_cmdcall_push_arg(
	bshell_cmdcall *cmdcall,
	fx_value arg)
{
	FX_CLASS_DISPATCH_STATIC(
		BSHELL_TYPE_CMDCALL,
		cmdcall_push_arg,
		cmdcall,
		arg);
}

enum bshell_status bshell_cmdcall_resolve(
	bshell_cmdcall *cmdcall,
	struct bshell_runtime *rt)
{
	FX_CLASS_DISPATCH_STATIC(
		BSHELL_TYPE_CMDCALL,
		cmdcall_resolve,
		cmdcall,
		rt);
}

enum bshell_status bshell_cmdcall_process_record(
	bshell_cmdcall *cmdcall,
	bshell_pipeline *pipeline,
	struct bshell_runtime *rt,
	enum bshell_command_position position)
{
	FX_CLASS_DISPATCH_STATIC(
		BSHELL_TYPE_CMDCALL,
		cmdcall_process_record,
		cmdcall,
		pipeline,
		rt,
		position);
}

FX_TYPE_CLASS_BEGIN(bshell_cmdcall)
	FX_TYPE_VTABLE_INTERFACE_BEGIN(fx_object, FX_TYPE_OBJECT)
		FX_INTERFACE_ENTRY(to_string) = NULL;
	FX_TYPE_VTABLE_INTERFACE_END(fx_object, FX_TYPE_OBJECT)

	FX_TYPE_CONSTRUCTOR("create", bshell_cmdcall_create, 0, FX_TYPE_VOID);
FX_TYPE_CLASS_END(bshell_cmdcall)

FX_TYPE_DEFINITION_BEGIN(bshell_cmdcall)
	FX_TYPE_ID(0x08aeb275, 0xc09b, 0x4c3a, 0xa8df, 0xd9fba0bb4571);
	FX_TYPE_NAME("bshell.cmdcall");
	FX_TYPE_CLASS(bshell_cmdcall_class);
	FX_TYPE_INSTANCE_PRIVATE(struct bshell_cmdcall_p);
	FX_TYPE_INSTANCE_FINI(cmdcall_fini);
FX_TYPE_DEFINITION_END(bshell_cmdcall)