From 36e7db3271b4485f0426aa09685d3cdd16a0b726 Mon Sep 17 00:00:00 2001
From: Randy Gingeleski <rjg26247@gmail.com>
Date: Tue, 26 Feb 2019 19:35:25 -0500
Subject: [PATCH] #33 mostly implement consolidate_deps.py

---
 consolidate_deps.py | 122 +++++++++++++++++++++++++++++++++++++-------
 1 file changed, 103 insertions(+), 19 deletions(-)

diff --git a/consolidate_deps.py b/consolidate_deps.py
index f264ffe..777b01e 100644
--- a/consolidate_deps.py
+++ b/consolidate_deps.py
@@ -3,9 +3,11 @@
 
 from plugins import *
 
+import os
+
 #######################################################################################################################
 
-class DependenciesHolder:
+class RequirementsHolder:
     """
     TODO document me
     """
@@ -14,15 +16,15 @@ def __init__(self):
         """
         TODO document me
         """
-        self.dependencies = []
+        self.requirements = []
 
     def add(self, obj_to_add):
         """
         TODO document me
         """
-        if len(self.dependencies) == 0:
-            self.dependencies.append(obj_to_add)
-        elif len(self.dependencies) == 1:
+        if len(self.requirements) == 0:
+            self.requirements.append(obj_to_add)
+        elif len(self.requirements) == 1:
             # TODO
             pass
         else:
@@ -38,19 +40,101 @@ def add(self, obj_to_add):
 
 #######################################################################################################################
 
+def get_reqs_tuple(dep_line):
+    """
+    Takes in a dependency line (think requirements.txt) then returns
+    a tuple where dependency name is index 0, the version specifier is
+    index 1, and the version number is in the final index, 2.
+
+    Params:
+        dep_line (str)
+
+    Returns:
+        (tuple)
+    """
+    if '==' in dep_line:
+        version_spec = '=='
+    elif '>=' in dep_line:
+        version_spec = '>='
+    elif '<=' in dep_line:
+        version_spec = '<='
+    else:
+        raise RuntimeError('Unexpected version specifier in dependency string ' + dep)
+    req_tuple = tuple(dep_line.split(version_spec).insert(1, version_spec))
+    return req_tuple
+
+def consolidate_req_from_multiple(req_tuple_list):
+    """
+    Takes a list of dependency tuples that are the same package and returns
+    just one tuple of the latest possible version.
+
+    Params:
+        req_tuple_list (list)
+
+    Returns:
+        (tuple)
+    """
+    # TODO
+    return req_tuple_list[0]
+
+def make_requirementstxt_string(reqs):
+    """
+    Takes a list of dependency tuples and returns a string that can be
+    written out as a requirements.txt
+
+    Params:
+        reqs (list)
+
+    Returns:
+        (str)
+    """
+    requirementstxt_lines = []
+    # Take the requirements list and sort it by first element (package name)
+    reqs_sorted = sorted(reqs, key=lambda x : x[0])
+    for i, req in enumerate(reqs_sorted):
+        # If there's at least one more element
+        if len(reqs_sorted) > i + 1:
+            # And the name is different than this one
+            if req[0] != reqs_sorted[i+1][0]:
+                # Just add the package
+                this_req_line = req[0] + req[1] + req[2]
+                requirementstxt_lines.append(this_req_line)
+            else:
+                # Figure out all the versions of this requirement - may have more than two
+                this_req_tuples = [req, reqs_sorted[i+1]]
+                # Check the subset of requirements after the next one...
+                reqs_after_that = reqs_sorted[i+2:] # <- will be empty if the indices don't go that high
+                for req_after in reqs_after_that:
+                    # Once/if we find a dependency with a different name, break
+                    if req_after[0] != req[0]:
+                        break
+                    this_req_tuples.append(req_after)
+                this_req = consolidate_req_from_multiple(this_req_tuples)
+                this_req_line = req[0] + req[1] + req[2]
+                requirementstxt_lines.append(this_req_line)
+    requirementstxt_str = '\n'.join(requirementstxt_lines)
+    return requirementstxt_str
+
+#######################################################################################################################
+
 if __name__ == '__main__':
-    dependencies = DependenciesHolder()
-    # TODO get existing dependencies
+    requirements = RequirementsHolder()
+    reqs_f = open('requirements.txt', 'r')
+    reqs_lines = reqs_f.readlines()
+    reqs_f.close()
+    for reqs_line in reqs_lines:
+        req_tuple = get_reqs_tuple(reqs_line)
+        requirements.append(req_tuple)
     for plugin in ALL_PLUGINS:
-        for dep in plugin.dependencies:
-            if '==' in dep:
-                version_spec = '=='
-            elif '>=' in dep:
-                version_spec = '>='
-            elif '<=' in dep:
-                version_spec = '<='
-            else:
-                raise RuntimeError('Unexpected version specifier in dependency string ' + dep)
-            dep_tuple = dep.split(version_spec).insert(1, version_spec)
-            dependencies.add(dep_tuple)
-    # TODO replace existing requirements.txt with a new one
+        for dep in plugin.requirements:
+            req_tuple = get_reqs_tuple(dep)
+            requirements.append(req_tuple)
+    requirementstxt_str = make_requirementstxt_string(requirements)
+    # Write new requirements.txt out as requirements.txt.new before swapping with original
+    reqs_new_f = open('requirements.txt.new', 'w')
+    reqs_new_f.write(requirementstxt_str)
+    reqs_new_f.close()
+    # Now delete original requirements.txt
+    os.remove('requirements.txt')
+    # Finally rename requirements.txt.new as requirements.txt
+    os.rename('requirements.txt.new', 'requirements.txt')