#!/bin/bash

#
# git recent 2.0 - switching branches, but so fancy
#
# - view recently edited local branches
# - see unique commits to that branch, and optionally the branch diff (against the main/master/primary branch) with Ctrl-o
# - hit Enter to checkout the selected branch.
# - text filtering against branch names, too.
#

branches_format="%(color:yellow)%(refname:short)%(color:reset)"
commits_format="%C(red bold)%h %C(bold blue)%an %C(bold green)%ad %Creset%s"

# The primary branch
mainormaster() {
  (git branch --format '%(refname:short)' --sort=-committerdate --list master main; echo main) | head -n1 || echo main
}

uniqcommits_cmd="git log --date=human --color=always --format='$commits_format' --no-merges origin/$(mainormaster)..{1}"

diffbranch_cmd="git diff --color=always origin/$(mainormaster)...{}"
# Progressive enhancement if you have delta or diff-so-fancy
if command -v delta >/dev/null 2>&1; then
  diffbranch_cmd="$diffbranch_cmd | delta"
elif command -v diff-so-fancy >/dev/null 2>&1; then
  diffbranch_cmd="$diffbranch_cmd | diff-so-fancy"
fi

# fzf basic inspiration:
# - https://github.com/junegunn/fzf/wiki/Examples#git, https://github.com/junegunn/fzf/wiki/Examples-(fish)#git
# Hardcore inspiration:
# - https://github.com/junegunn/fzf-git.sh

_browse_branches() {
  git for-each-ref --color=always --sort=-authordate "refs/heads/" --format="$branches_format" \
    |  fzf-tmux  --ansi  -p80%,60%  -- \
        --layout=reverse --multi --height=90% --min-height=20  \
        --border-label-pos=2 --border-label '🌲 Branches' --border \
        --no-hscroll --no-multi \
        --preview-window='right,70%,border-left,border-rounded' --preview="$uniqcommits_cmd" --preview-label="Commits unique to branch" \
        --header $'ENTER (checkout)\nCTRL-O (show branch diff)\n' \
        --bind 'preview-scroll-up:preview-up+preview-up+preview-up' \
        --bind 'preview-scroll-down:preview-down+preview-down+preview-down' \
        --bind "ctrl-o:preview:$diffbranch_cmd" 
} 

chosen_branch="$(_browse_branches)"
if [[ -n "$chosen_branch" ]]; then
  echo git checkout "$chosen_branch"
  git checkout "$chosen_branch"
fi