diff --git a/README.md b/README.md
index 8594eb4..31fbd21 100644
--- a/README.md
+++ b/README.md
@@ -9,30 +9,36 @@ python-terraform is a python module provide a wrapper of `terraform` command lin
 ## Installation
     pip install python-terraform
 
+## Implementation
+IMHO, how terraform design boolean options is confusing. 
+Take `input=True` and `-no-color` option of `apply` command for example,
+they're all boolean value but with different option type. 
+This make api caller don't have a general rule to follow but to do 
+a exhaustive method implementation which I don't prefer to.
+Therefore I end-up with using `IsFlagged` or `IsNotFlagged` as value of option 
+like `-no-color` and `True/False` value reserved for option like 
+
 ## Usage
 For any terraform command
 
-    def cmd(self, cmd, *args, **kwargs):
-        """
-        run a terraform command, if success, will try to read state file
-        :param cmd: command and sub-command of terraform, seperated with space
-                    refer to https://www.terraform.io/docs/commands/index.html
-        :param args: arguments of a command
-        :param kwargs:  any option flag with key value without prefixed dash character
-                if there's a dash in the option name, use under line instead of dash,
-                    ex. -no-color --> no_color
-                if it's a simple flag with no value, value should be IsFlagged
-                    ex. cmd('taint', allow＿missing=IsFlagged)
-                if it's a boolean value flag, assign True or false
-                if it's a flag could be used multiple times, assign list to it's value
-                if it's a "var" variable flag, assign dictionary to it
-                if a value is None, will skip this option
-        :return: ret_code, out, err
-
+    from python_terraform import Terraform
+    t = Terraform()
+    return_code, stdout, stderr = t.<cmd_name>(*arguments, **options)
+    
+For any options
+    
+    if there's a dash in the option name, use under line instead of dash,
+        ex. -no-color --> no_color
+    if it's a simple flag with no value, value should be IsFlagged
+        ex. cmd('taint', allow＿missing=IsFlagged)
+    if it's a boolean value flag like "-refresh=true", assign True or False
+    if it's a flag could be used multiple times, assign list to it's value
+    if it's a "var" variable flag, assign dictionary to it
+    if a value is None, will skip this option
 
 ## Examples
-### Have a test.tf file under folder "/home/test"
-#### apply with variables a=b, c=d, refresh=False, no color in the output
+### Have a test.tf file under folder "/home/test" 
+#### 1. apply with variables a=b, c=d, refresh=false, no color in the output
 In shell:
 
     cd /home/test
@@ -41,19 +47,26 @@ In shell:
 In python-terraform:
 
     from python_terraform import Terraform
-    tf = terraform(working_dir='/home/test')
+    tf = Terraform(working_dir='/home/test')
     tf.apply(no_color=IsFlagged, refresh=False, var={'a':'b', 'c':'d'})
-#### taint command, allow-missing and no color
+    
+or
+
+    from python_terraform import Terraform
+    tf = Terraform()
+    tf.apply('/home/test', no_color=IsFlagged, refresh=False, var={'a':'b', 'c':'d'})
+    
+#### 2. fmt command, diff=true
 In shell:
 
     cd /home/test
-    terraform taint -allow-missing -no-color
+    terraform fmt -diff=true 
     
 In python-terraform:
     
     from python_terraform import Terraform
     tf = terraform(working_dir='/home/test')
-    tf.cmd('taint', allow_missing=IsFlagged, no_color=IsFlagged)
+    tf.fmt(diff=True)
     
 
     
diff --git a/python_terraform/__init__.py b/python_terraform/__init__.py
index 63ef189..9c1bc2c 100644
--- a/python_terraform/__init__.py
+++ b/python_terraform/__init__.py
@@ -5,6 +5,7 @@ import subprocess
 import os
 import json
 import logging
+import tempfile
 
 from python_terraform.tfstate import Tfstate
 
@@ -19,7 +20,7 @@ class IsNotFlagged:
     pass
 
 
-class Terraform:
+class Terraform(object):
     """
     Wrapper of terraform command line tool
     https://www.terraform.io/
@@ -38,7 +39,8 @@ class Terraform:
         :param state: path of state file relative to working folder
         :param variables: variables for apply/destroy/plan command
         :param parallelism: parallelism for apply/destroy command
-        :param var_file: if specified, variables will not be used
+        :param var_file: passed as value of -var-file option, could be string or list
+            list stands for multiple -var-file option
         :param terraform_bin_path: binary path of terraform
         """
         self.working_dir = working_dir
@@ -49,9 +51,18 @@ class Terraform:
         self.terraform_bin_path = terraform_bin_path \
             if terraform_bin_path else 'terraform'
         self.var_file = var_file
+        self.temp_var_files = VaribleFiles()
 
         # store the tfstate data
-        self.tfstate = dict()
+        self.tfstate = None
+        self.read_state_file(self.state)
+
+    def __getattr__(self, item):
+        def wrapper(*args, **kwargs):
+            print('called with %r and %r' % (args, kwargs))
+            return self.cmd(item, *args, **kwargs)
+
+        return wrapper
 
     def apply(self, dir_or_plan=None, **kwargs):
         """
@@ -74,7 +85,7 @@ class Terraform:
         option_dict['var_file'] = self.var_file
         option_dict['parallelism'] = self.parallelism
         option_dict['no_color'] = IsFlagged
-        option_dict['input'] = True
+        option_dict['input'] = False
         option_dict.update(kwargs)
         args = [dir_or_plan] if dir_or_plan else []
         return args, option_dict
@@ -125,11 +136,12 @@ class Terraform:
                     cmds += ['-{k}={v}'.format(k=k, v=sub_v)]
                 continue
 
+            # right now we assume only variables will be passed as dict
+            # since map type sent in string won't work, create temp var file for
+            # variables, and clean it up later
             if type(v) is dict:
-                for sub_k, sub_v in v.items():
-                    cmds += ["-{k}='{var_k}={var_v}'".format(k=k,
-                                                             var_k=sub_k,
-                                                             var_v=sub_v)]
+                filename = self.temp_var_files.create(v)
+                cmds += ['-var-file={0}'.format(filename)]
                 continue
 
             # simple flag,
@@ -185,6 +197,8 @@ class Terraform:
             self.read_state_file()
         else:
             log.warn('error: {e}'.format(e=err))
+
+        self.temp_var_files.clean_up()
         return ret_code, out.decode('utf-8'), err.decode('utf-8')
 
     def output(self, name):
@@ -220,3 +234,26 @@ class Terraform:
             file_path = os.path.join(self.working_dir, file_path)
 
         self.tfstate = Tfstate.load_file(file_path)
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        self.temp_var_files.clean_up()
+
+
+class VaribleFiles(object):
+    def __init__(self):
+        self.files = []
+
+    def create(self, variables):
+        with tempfile.NamedTemporaryFile('w+t', delete=False) as temp:
+            logging.debug('{0} is created'.format(temp.name))
+            self.files.append(temp)
+            temp.write(json.dumps(variables))
+            file_name = temp.name
+
+        return file_name
+
+    def clean_up(self):
+        for f in self.files:
+            os.unlink(f.name)
+
+        self.files = []
diff --git a/python_terraform/tfstate.py b/python_terraform/tfstate.py
index 22e5c05..497e757 100644
--- a/python_terraform/tfstate.py
+++ b/python_terraform/tfstate.py
@@ -29,6 +29,6 @@ class Tfstate(object):
             tf_state.tfstate_file = file_path
             return tf_state
 
-        log.warn('{0} is not exist'.format(file_path))
+        log.debug('{0} is not exist'.format(file_path))
 
         return Tfstate()
\ No newline at end of file
diff --git a/test/apply_tf/test.tf b/test/apply_tf/test.tf
deleted file mode 100644
index c247514..0000000
--- a/test/apply_tf/test.tf
+++ /dev/null
@@ -1,8 +0,0 @@
-variable "test_var" {}
-
-provider "archive" {
-}
-
-output "test_output" {
-  value = "${var.test_var}"
-}
\ No newline at end of file
diff --git a/test/test_terraform.py b/test/test_terraform.py
index a1d0cfb..2bb6804 100644
--- a/test/test_terraform.py
+++ b/test/test_terraform.py
@@ -4,22 +4,20 @@ import os
 import logging
 import re
 
-logging.basicConfig(level=logging.WARN)
+logging.basicConfig(level=logging.DEBUG)
 current_path = os.path.dirname(os.path.realpath(__file__))
 
 STRING_CASES = [
      [
          lambda x: x.generate_cmd_string('apply', 'the_folder',
-                                         no_color=IsFlagged,
-                                         var={'a': 'b', 'c': 'd'}),
-         "terraform apply -var='a=b' -var='c=d' -no-color the_folder"
+                                         no_color=IsFlagged),
+         "terraform apply -no-color the_folder"
      ],
      [
-         lambda x: x.generate_cmd_string('push', 'path',
-                                         var={'a': 'b'}, vcs=True,
+         lambda x: x.generate_cmd_string('push', 'path', vcs=True,
                                          token='token',
                                          atlas_address='url'),
-         "terraform push -var='a=b' -vcs=true -token=token -atlas-address=url path"
+         "terraform push -vcs=true -token=token -atlas-address=url path"
      ],
  ]
 
@@ -27,14 +25,14 @@ CMD_CASES = [
     ['method', 'expected_output'],
     [
         [
-            lambda x: x.cmd('plan', 'apply_tf', no_color=IsFlagged, var={'test_var': 'test'}) ,
+            lambda x: x.cmd('plan', 'var_to_output', no_color=IsFlagged, var={'test_var': 'test'}) ,
             "doesn't need to do anything"
         ]
     ]
 ]
 
 
-class TestTerraform:
+class TestTerraform(object):
     def teardown_method(self, method):
         """ teardown any state that was previously setup with a setup_method
         call.
@@ -66,35 +64,58 @@ class TestTerraform:
         assert expected_output in out
         assert ret == 0
 
+    @pytest.mark.parametrize(
+        ("folder", "variables", "var_files", "expected_output"),
+        [
+            ("var_to_output", {'test_var': 'test'}, None, "test_output=test"),
+            ("var_to_output", {'test_list_var': ['c', 'd']}, None, "test_list_output=[c,d]"),
+            ("var_to_output", {'test_map_var': {"c": "c", "d": "d"}}, None, "test_map_output={a=ab=bc=cd=d}"),
+            ("var_to_output", {'test_map_var': {"c": "c", "d": "d"}}, 'var_to_output/test_map_var.json', "test_map_output={a=ab=bc=cd=de=ef=f}")
+        ])
+    def test_apply(self, folder, variables, var_files, expected_output):
+        tf = Terraform(variables=variables, var_file=var_files)
+        ret, out, err = tf.apply(folder)
+        assert ret == 0
+        assert expected_output in out.replace('\n', '').replace(' ', '')
+        assert err == ''
+
+
     def test_state_data(self):
         cwd = os.path.join(current_path, 'test_tfstate_file')
         tf = Terraform(working_dir=cwd, state='tfstate.test')
         tf.read_state_file()
         assert tf.tfstate.modules[0]['path'] == ['root']
 
-    def test_apply(self):
-        cwd = os.path.join(current_path, 'apply_tf')
-        tf = Terraform(working_dir=cwd, variables={'test_var': 'test'})
-        ret, out, err = tf.apply(var={'test_var': 'test2'})
-        assert ret == 0
+    def test_pre_load_state_data(self):
+        cwd = os.path.join(current_path, 'test_tfstate_file')
+        tf = Terraform(working_dir=cwd, state='tfstate.test')
+        assert tf.tfstate.modules[0]['path'] == ['root']
 
-    def test_override_no_color(self):
-        cwd = os.path.join(current_path, 'apply_tf')
-        tf = Terraform(working_dir=cwd, variables={'test_var': 'test'})
-        ret, out, err = tf.apply(var={'test_var': 'test2'},
+    @pytest.mark.parametrize(
+        ("folder", 'variables'),
+        [
+            ("var_to_output", {'test_var': 'test'})
+        ]
+    )
+    def test_override_default(self, folder, variables):
+        tf = Terraform(variables=variables)
+        ret, out, err = tf.apply(folder, var={'test_var': 'test2'},
                                  no_color=IsNotFlagged)
         out = out.replace('\n', '')
         assert '\x1b[0m\x1b[1m\x1b[32mApply' in out
 
     def test_get_output(self):
-        cwd = os.path.join(current_path, 'apply_tf')
-        tf = Terraform(working_dir=cwd, variables={'test_var': 'test'})
-        tf.apply()
+        tf = Terraform(variables={'test_var': 'test'})
+        tf.apply('var_to_output')
         assert tf.output('test_output') == 'test'
 
     def test_destroy(self):
-        cwd = os.path.join(current_path, 'apply_tf')
-        tf = Terraform(working_dir=cwd, variables={'test_var': 'test'})
-        ret, out, err = tf.destroy()
+        tf = Terraform(variables={'test_var': 'test'})
+        ret, out, err = tf.destroy('var_to_output')
         assert ret == 0
         assert 'Destroy complete! Resources: 0 destroyed.' in out
+
+    def test_fmt(self):
+        tf = Terraform(variables={'test_var': 'test'})
+        ret, out, err = tf.fmt(diff=True)
+        assert ret == 0
diff --git a/test/var_to_output/test.tf b/test/var_to_output/test.tf
new file mode 100644
index 0000000..71c2e8c
--- /dev/null
+++ b/test/var_to_output/test.tf
@@ -0,0 +1,31 @@
+variable "test_var" {
+  default = ""
+}
+
+provider "archive" {}
+
+variable "test_list_var" {
+  type    = "list"
+  default = ["a", "b"]
+}
+
+variable "test_map_var" {
+  type = "map"
+
+  default = {
+    "a" = "a"
+    "b" = "b"
+  }
+}
+
+output "test_output" {
+  value = "${var.test_var}"
+}
+
+output "test_list_output" {
+  value = "${var.test_list_var}"
+}
+
+output "test_map_output" {
+  value = "${var.test_map_var}"
+}
diff --git a/test/var_to_output/test_map_var.json b/test/var_to_output/test_map_var.json
new file mode 100644
index 0000000..0673f77
--- /dev/null
+++ b/test/var_to_output/test_map_var.json
@@ -0,0 +1,7 @@
+{
+  "test_map_var":
+  {
+    "e": "e",
+    "f": "f"
+  }
+}
\ No newline at end of file