# Git branches in buffers.
#
# This small script provides convenience mechanisms to operate on Git branches by altering a buffer.
# It can:
#
# - Switch branches.
# - Create new branches with optional starting point.
# - Rename branches.
# - Delete and force-delete branches.

declare-option str git_bin "git --no-optional-locks"
declare-option str git_list_local_branches "%opt{git_bin} branch"
declare-option str git_branch "xargs %opt{git_bin} branch"
declare-option str git_branch_rename "xargs %opt{git_bin} branch -m"
declare-option str git_branch_switch "xargs %opt{git_bin} switch"

declare-user-mode git-branches

# Create a branch listing buffer.
define-command git-branches %{
  edit -scratch "*git-branches*"
  set-option buffer filetype git-branches
  git-branches-refresh

  # highlighters
  add-highlighter buffer/ ref git-branches

	# mappings
  map buffer normal            <ret> ':git-branches-switch<ret>'    -docstring 'switch branch'
  map buffer git-branches <ret> ':git-branches-switch<ret>'         -docstring 'switch branch'
  map buffer git-branches c     ':git-branches-commit-pending<ret>' -docstring 'commit pending changes'
  map buffer git-branches d     ':git-branches-delete<ret>'         -docstring 'delete branch'
  map buffer git-branches D     ':git-branches-force-delete<ret>'   -docstring 'force-delete branch'
  map buffer git-branches g     ':git-branches-refresh<ret>'        -docstring 'refresh'
  map buffer git-branches n     ':git-branches-new<ret>'            -docstring 'new branch'
  map buffer git-branches r     ':git-branches-rename<ret>'         -docstring 'rename branch'
}

# Save the content of the current branch (primary sel) in the "b register.
define-command -hidden git-save-branch-name %{
  try %{
    execute-keys ';,ghll<a-E>"by'
  }
}

# Restore the position of the main selection. Required to have saved something in the "b register.
define-command -hidden git-restore-branch-name %{
  try %{
    execute-keys '/<c-r>b<ret>;'
  }
}

# Refresh the content of the branch buffer. This will lose all information that have been modified in it.
# TODO: support + branches (I don’t recall what they are, but I think it means they are checked out in
# working trees?)
define-command -hidden git-branches-refresh %{
  evaluate-commands -save-regs b %{
    git-save-branch-name
    execute-keys -draft "%%|%opt{git_list_local_branches}<ret>"

    # replace the * for current branch by c
    execute-keys -draft '%s^\*<ret>rc'

    git-restore-branch-name
    execute-keys 'gh'
  }
}

# Delete a branch.
#
# Various situations are possible, and are acted upon by dispatching to git-branches-delete-- based on the
# first charact of every selection’s line.
define-command -hidden git-branches-delete %{
  execute-keys -itersel '<a-s>ghy:git-branches-delete--<c-r>" d<ret>'
}

# Force delete a branch.
#
# Same as the non-force version.
define-command -hidden git-branches-force-delete %{
  execute-keys -itersel '<a-s>ghy:git-branches-delete--<c-r>" D<ret>'
}

# Switch the branch as pending deletion.
#
# The argument is used for regular deletion (d) or force-deletion (D).
define-command -hidden git-branches-delete-- -params 1 %{
  execute-keys "ghr%arg{1}gh"
}

# Deletion of a rename line simply removes the rename annotation, and delete.
define-command -hidden git-branches-delete--r -params 1 %{
  git-branches-unrename
  git-branches-delete-- %arg{1}
}

# Undelete.
define-command -hidden git-branches-delete--d -params 1 %{
  execute-keys 'ghr gh'
}

# Force delete.
define-command -hidden git-branches-delete--D -params 1 %{
  execute-keys 'ghr gh'
}

# Deletion on current branches is simply not allowed for obvious reasons (Git will refuse it anyway).
define-command -hidden git-branches-delete--c -params 1 %{
  fail 'cannot delete current branches'
}

# Switch to a given branch (primary selection only).
define-command -hidden git-branches-switch %{
  execute-keys -draft ",ghllGl<a-|>%opt{git_branch_switch}<ret>"
  git-branches-refresh
}

# Rename branches.
#
# Dispatching is done via git-branches-rename--.
define-command -hidden git-branches-rename %{
  execute-keys -itersel '<a-s>ghy:git-branches-rename--<c-r>"<ret>'
}

# Rename branch implementation.
define-command -hidden git-branches-rename-- %{
  execute-keys -save-regs b 'ghrrll<a-E>"bya <c-r>b<esc>;<a-i><a-w>'
}

# Renaming a deletion branch.
define-command -hidden git-branches-rename--d %{
  git-branches-rename--
}

# Remove renaming annotation.
define-command -hidden git-branches-rename--r %{
  git-branches-unrename
}

# We forbid renaming current branches.
define-command -hidden git-branches-rename--c %{
  fail 'cannot rename current branches'
}

# Unrename (remove rename annotations).
define-command -hidden git-branches-unrename %{
  execute-keys 'ghr <a-E><a-E>dgh'
}

# Create new branches.
#
# This is a handy version that uses the optional second argument by yanking the branches selections are on.
define-command -hidden git-branches-new %{
  execute-keys '<a-s>ghll<a-E>ygjo<esc><a-P>a<ret><esc>in new-<c-r>" <esc>hh<a-i><a-w>'
}

# Execute pending deletions. Called on commit.
define-command -hidden git-branches-execute-delete %{
  try %{
    execute-keys -draft -itersel "%%s^(d|D)y<ret>llGl<a-|>%opt{git_branch} -<c-r>""<ret>"
  }
}

# Execute pending renames. Called on commit.
define-command -hidden git-branches-execute-rename %{
  try %{
    execute-keys -draft "%%s^r<ret>ddx_<a-|>%opt{git_branch_rename}<ret>"
  }
}

# Execute pending creations. Called on commit.
define-command -hidden git-branches-execute-new %{
  try %{
    execute-keys -draft "%%s^n<ret>ddx_<a-|>%opt{git_branch}<ret>"
  }
}

# Commit pending modifications in the buffer and refresh.
define-command -hidden git-branches-commit-pending %{
  git-branches-execute-delete
  git-branches-execute-rename
  git-branches-execute-new
  git-branches-refresh
}

# Highlighting.
set-face global GitOpsBranchCurrent green
set-face global GitOpsBranchOther default
set-face global GitOpsBranchDeleted red+s
set-face global GitOpsBranchForceDeleted red+bs
set-face global GitOpsBranchRenameSource blue
set-face global GitOpsBranchRenameDest cyan+b
set-face global GitOpsBranchNewName blue
set-face global GitOpsBranchNewStart yellow+i

# Highlighters.
add-highlighter shared/git-branches group
add-highlighter shared/git-branches/current-branch regex '^(c)\s+([^\n]+)$' "1:black" "2:GitOpsBranchCurrent"
add-highlighter shared/git-branches/other-branch regex '^\s+([^\n]+)$' "1:GitOpsBranchOther"
add-highlighter shared/git-branches/deleted-branch regex '^(d)\s+([^\n]+)$' "1:black" "2:GitOpsBranchDeleted"
add-highlighter shared/git-branches/force-deleted-branch regex '^(D)\s+([^\n]+)$' "1:black" "2:GitOpsBranchForceDeleted"
add-highlighter shared/git-branches/renamed-branch regex '^(r)\s+([^\n ]+) ([^\n ]*)$' "1:black" "2:GitOpsBranchRenameSource" "3:GitOpsBranchRenameDest"
add-highlighter shared/git-branches/new-branch regex '^(n)\s+([^\n ]+) ?([^\n ]*)?$' "1:black" "2:GitOpsBranchNewName" "3:GitOpsBranchNewStart"