From 480baf8da7daae8b958ec2edc265227503ba160b Mon Sep 17 00:00:00 2001
From: ItsDrike <itsdrike@protonmail.com>
Date: Sun, 29 May 2022 01:15:40 +0200
Subject: [PATCH] Automatically define pyenv python aliases

---
 home/.config/shell/aliases  |  27 ++---
 home/.config/shell/py-alias | 195 ++++++++++++++++++++++++++++++++++++
 2 files changed, 201 insertions(+), 21 deletions(-)
 create mode 100755 home/.config/shell/py-alias

diff --git a/home/.config/shell/aliases b/home/.config/shell/aliases
index 392c711..7b886eb 100755
--- a/home/.config/shell/aliases
+++ b/home/.config/shell/aliases
@@ -79,27 +79,6 @@ alias zb='z -b'         # restrict matches to parent directories
 alias zi='z -I'         # cd with interactive fzf selection
 alias zbi='z -b -I'     # pick parent directory to cd into with fzf
 
-## Make aliases for individual cpython/pypy versions
-py_versions="\n2\n3\n3.6\n3.7\n3.8\n3.9\n3.10"
-# shellcheck disable=SC2139
-echo "$py_versions" | while read -r version; do
-    for python in python pypy; do
-        [ "$python" = "python" ] && prefix="py" || prefix="pypy"
-
-        if command -v "$python$version" >/dev/null; then
-            if [ "$python" = "python" ]; then
-                alias "pip$version=$python$version -m pip"
-            else
-                alias "ppip$version=$python$version -m pip"
-            fi
-            alias "$prefix${version}pip=$python$version -m pip"
-            alias "$prefix$version=$python$version"
-            alias "i$prefix$version=$python$version -c 'import IPython;IPython.start_ipython()'"
-            alias "b$prefix$version=$python$version -c 'from bpython.curtsies import main;import sys;sys.exit(main())'"
-        fi
-    done
-done
-
 # Fallbacks
 command -v hd > /dev/null || alias hd='hexdump -C' # Cannonical hex dump; some systems have this symlinked
 command -v md5sum > /dev/null || alias md5sum='md5' # Fallback from `md5sum` to `md5`
@@ -295,6 +274,12 @@ if [ ! "$(uname -s)" = 'Darwin' ]; then
     fi
 fi
 
+# Autogenerate python aliases
+if [ -f ~/.config/shell/py-alias ]; then
+    # shellcheck source=/home/itsdrike/.config/shell/py-alias
+    . "$HOME/.config/shell/py-alias"
+fi
+
 # Functions
 if [ -f ~/.config/shell/functions ]; then
     # shellcheck source=/home/itsdrike/.config/shell/functions
diff --git a/home/.config/shell/py-alias b/home/.config/shell/py-alias
new file mode 100755
index 0000000..70f57b0
--- /dev/null
+++ b/home/.config/shell/py-alias
@@ -0,0 +1,195 @@
+#!/usr/bin/env zsh
+# Simple script which automatically defines certain aliases for python,
+# which will automatically use certain python version 
+# Versions are automatically obtained from $PYENV_ROOT/versions directories
+# NOTE: This assumes that all folders in this directory are valid python versions
+#
+# Assume we have these installed pyenv python versions 3.6.5, 3.6.12 and 3.10.1:
+#   - Set full-version aliases: py3.6.5, py3.6.12 and py3.10.1
+#   - Set py3 to 3.10.1 (latest with major version 3)
+#   - Set py3.6 to 3.6.12 (latest with major version 3 and minor version 6)
+#   - Set py3.10 to 3.10.1 (latest, and only python with major version 3 and minor version 10)
+
+
+# Define all wanted aliases for a given python version
+# $1 - full valid pyenv python version (for example '3.6.12', `3.11-dev`, or `pypy3.6-7.2.0-src`)
+# $2 - version used in the alias (for example '3.6', '3', or even '', but also `pypy3.7`, ...)
+define_aliases() {
+    version="$1"
+    alias_version="$2"
+    cmd_prefix="PYENV_VERSION=$version"
+
+    alias "py$alias_version=$cmd_prefix python"
+    alias "ipy$alias_version=$cmd_prefix ipython"
+    alias "bpy$alias_version=$cmd_prefix bpython"
+    alias "pydoc$alias_version=$cmd_prefix pydoc"
+    alias "pytest$alias_version=$cmd_prefix pytest"
+}
+
+# Handle splitting full version into prefix, version number and suffix
+# Because of the huge variaty of python implemenations and their different namings,
+# this function will only be able to handle the default CPython version names,
+# which follow the regex pattern of: '\d+\.\d+\.\d+', the rest will print 'full_version;;'
+# In the future, this may also include support for some other naming schemes.
+# $1 - full valid pyenv python version (for example '3.6.12', `3.11-dev`, or `pypy3.6-7.2.0-src`)
+parse_python_version() {
+    full_version="$1"
+    if echo "$full_version" | grep -E "[0-9]+\.[0-9]+\.[0-9]+" >/dev/null; then
+        echo ";$full_version;"
+    else
+        echo ';;'
+    fi
+}
+
+# Prints version number extracted from alias for given version
+# $1 - version used in the alias (for example '3.6', '3', or even '', but also 'pypy3.6', ...)
+get_alias_version() {
+    alias_version="$1"
+    definition="$(alias "py$alias_version")"
+    full_version="$(echo "$definition" | cut -d= -f3 | cut -d' '  -f1)"
+
+    version_info="$(parse_python_version "$full_version")"
+    version="$(echo "$version_info" | cut -d';' -f2)"
+    echo "$version"
+}
+
+# Compares 2 python versions in major, minor and micro parts
+# $1 - version #1
+# $2 - version #2
+# Returns:
+# 0 - version #1 is newer
+# 1 - version #2 is newer
+# 2 - versions are equal
+version_compare() {
+    version_1="$1"
+    version_2="$2"
+    # ZSH Only:
+    version_1=(${(@s:.:)version_1})
+    version_2=(${(@s:.:)version_2})
+    major_1=$version_1[1]
+    major_2=$version_2[1]
+    minor_1=$version_1[2]
+    minor_2=$version_2[2]
+    micro_1=$version_1[3]
+    micro_2=$version_2[3]
+    # POSIX, but slow:
+    # major_1="$(echo "$version_1" | cut -d. -f1)"
+    # major_2="$(echo "$version_2" | cut -d. -f1)"
+    # minor_1="$(echo "$version_1" | cut -d. -f2)"
+    # minor_2="$(echo "$version_2" | cut -d. -f2)"
+    # micro_1="$(echo "$version_1" | cut -d. -f3)"
+    # micro_2="$(echo "$version_2" | cut -d. -f3)"
+
+    # Compare majors
+    if [ $major_1 -gt $major_2 ]; then
+        # version 1's major is bigger, version 1 is newer
+        return 0
+    elif [ $major_1 -lt $major_2 ]; then
+        # version 1's major is smaller, version 2 is newer
+        return 1
+    fi
+
+    # Majors equal, compare minors
+    if [ $minor_1 -gt $minor_2 ]; then
+        # version 1's minor is bigger, version 1 is newer
+        return 0
+    elif [ $minor_1 -lt $minor_2 ]; then
+        # version 1's major is smaller, version 2 is newer
+        return 1
+    fi
+
+    # Minors equal, compare micros
+    if [ $micro_1 -gt $micro_2 ]; then
+        # version 1's micro is bigger, version 1 is newer
+        return 0
+    elif [ $micro_1 -lt $micro_2 ]; then
+        # version 1's micro is smaller, version 2 is newer
+        return 1
+    fi
+
+    # Micros equal, versions equal
+    return 2
+}
+
+# Define new aliases if they don't already exsist, in which case override
+# if the current version is newer than the version in the alias
+# $1 - full valid pyenv python version (for example '3.6.12', `3.11-dev`, or `pypy3.6-7.2.0-src`)
+# $2 - version used in the alias (for example '3.6', '3', or even '', but also `pypy3.7`, ...)
+try_define_aliases() {
+    version="$1"
+    alias_version="$2"
+
+    # Check if alias already exists
+    if alias "py$alias_version" >/dev/null; then
+        # Compare version from the existing alias with current version,
+        # if current is newer, override the existing alias(es)
+        defined_version="$(get_alias_version "$alias_version")"
+        if version_compare "$version" "$defined_version"; then
+            define_aliases "$version" "$alias_version"
+            # echo "Overwrote '$alias_version' aliases to point to '$version'"
+            return 0
+        else
+            return 1
+        fi
+    fi
+
+    # The aliases aren't already defined, it's safe to create them
+    define_aliases "$version" "$alias_version"
+    # echo "Made '$alias_version' aliases pointing to '$version'"
+    return 0
+}
+
+define_version_aliases() {
+    prefix="$1"
+    version="$2"
+    suffix="$3"
+
+
+    # ZSH only:
+    version_data=(${(@s:.:)version})
+    major_version=$version_data[0]
+    minor_version=$version_data[1]
+    # POSIX, but slow:
+    # major_version="$(echo "$version" | cut -d. -f1)"
+    # minor_version="$(echo "$version" | cut -d. -f2)"
+
+    # Define the major.minor.micro (full) alias
+    try_define_aliases "$version" "$prefix$version$suffix"
+    # Define the major.minor alias
+    try_define_aliases "$version" "$prefix$major_version.$minor_version$suffix"
+    # Define the major alias
+    try_define_aliases "$version" "$prefix$major_version$suffix"
+    # Define top level alias
+    try_define_aliases "$version" "$prefix$suffix"
+}
+
+for python_dir in "$PYENV_ROOT"/versions/*/ ; do
+    full_version="$(basename $python_dir)"
+
+    version_info="$(parse_python_version "$full_version")"
+    if [ $version_info = ';;' ]; then
+        # Version info wasn't obtained successfully, skip this version
+        echo "Skipped $full_version"
+        continue
+    fi
+
+    # ZSH only:
+    version_data=(${(@s:;:)version_info})
+    prefix=$version_data[0]
+    version=$version_data[1]
+    suffix=$version_data[2]
+    # POSIX, but slow:
+    # prefix="$(echo "$version_info" | cut -d';' -f1)"
+    # version="$(echo "$version_info" | cut -d';' -f2)"
+    # suffix="$(echo "$version_info" | cut -d';' -f3)"
+
+    # startTime=$(date +%N)
+    define_version_aliases "$prefix" "$version" "$suffix"
+    # endTime=$(date +%N)
+    # nanos="$(expr $endTime - $startTime)"
+    # echo "took $(expr $nanos / 1000000) miliseconds"
+done
+
+if command -v poetry >/dev/null 2>&1; then
+    alias poetry-pyenv='poetry env use "$(pyenv which python)" && poetry install'
+fi