diffs.nvim/lua/diffs/init.lua
Barrett Ruth 3482e25c41 fix(highlight): use hl_group instead of line_hl_group for diff backgrounds
line_hl_group bg occupies a separate rendering channel from hl_group in
Neovim's extmark system, causing character-level bg-only highlights to be
invisible regardless of priority. Switching to hl_group + hl_eol ensures
all backgrounds compete in the same channel.

Also reorders priorities (Normal 198 < line bg 199 < syntax 200 < char
bg 201), bumps char-level blend alpha from 0.4 to 0.7 for visibility,
and adds debug logging throughout the intra pipeline.
2026-02-06 18:28:22 -05:00

439 lines
12 KiB
Lua

---@class diffs.TreesitterConfig
---@field enabled boolean
---@field max_lines integer
---@class diffs.VimConfig
---@field enabled boolean
---@field max_lines integer
---@class diffs.IntraConfig
---@field enabled boolean
---@field algorithm string
---@field max_lines integer
---@class diffs.Highlights
---@field background boolean
---@field gutter boolean
---@field treesitter diffs.TreesitterConfig
---@field vim diffs.VimConfig
---@field intra diffs.IntraConfig
---@class diffs.FugitiveConfig
---@field horizontal string|false
---@field vertical string|false
---@class diffs.Config
---@field debug boolean
---@field debounce_ms integer
---@field hide_prefix boolean
---@field highlights diffs.Highlights
---@field fugitive diffs.FugitiveConfig
---@class diffs
---@field attach fun(bufnr?: integer)
---@field refresh fun(bufnr?: integer)
local M = {}
local highlight = require('diffs.highlight')
local log = require('diffs.log')
local parser = require('diffs.parser')
local ns = vim.api.nvim_create_namespace('diffs')
---@param hex integer
---@param bg_hex integer
---@param alpha number
---@return integer
local function blend_color(hex, bg_hex, alpha)
---@diagnostic disable: undefined-global
local r = bit.band(bit.rshift(hex, 16), 0xFF)
local g = bit.band(bit.rshift(hex, 8), 0xFF)
local b = bit.band(hex, 0xFF)
local bg_r = bit.band(bit.rshift(bg_hex, 16), 0xFF)
local bg_g = bit.band(bit.rshift(bg_hex, 8), 0xFF)
local bg_b = bit.band(bg_hex, 0xFF)
local blend_r = math.floor(r * alpha + bg_r * (1 - alpha))
local blend_g = math.floor(g * alpha + bg_g * (1 - alpha))
local blend_b = math.floor(b * alpha + bg_b * (1 - alpha))
return bit.bor(bit.lshift(blend_r, 16), bit.lshift(blend_g, 8), blend_b)
---@diagnostic enable: undefined-global
end
---@param name string
---@return table
local function resolve_hl(name)
local hl = vim.api.nvim_get_hl(0, { name = name })
while hl.link do
hl = vim.api.nvim_get_hl(0, { name = hl.link })
end
return hl
end
---@type diffs.Config
local default_config = {
debug = false,
debounce_ms = 0,
hide_prefix = false,
highlights = {
background = true,
gutter = true,
treesitter = {
enabled = true,
max_lines = 500,
},
vim = {
enabled = false,
max_lines = 200,
},
intra = {
enabled = true,
algorithm = 'auto',
max_lines = 500,
},
},
fugitive = {
horizontal = 'du',
vertical = 'dU',
},
}
---@type diffs.Config
local config = vim.deepcopy(default_config)
local initialized = false
---@type table<integer, boolean>
local attached_buffers = {}
---@type table<integer, boolean>
local diff_windows = {}
---@param bufnr integer
---@return boolean
function M.is_fugitive_buffer(bufnr)
return vim.api.nvim_buf_get_name(bufnr):match('^fugitive://') ~= nil
end
local dbg = log.dbg
---@param bufnr integer
local function highlight_buffer(bufnr)
if not vim.api.nvim_buf_is_valid(bufnr) then
return
end
vim.api.nvim_buf_clear_namespace(bufnr, ns, 0, -1)
local hunks = parser.parse_buffer(bufnr)
dbg('found %d hunks in buffer %d', #hunks, bufnr)
for _, hunk in ipairs(hunks) do
highlight.highlight_hunk(bufnr, ns, hunk, {
hide_prefix = config.hide_prefix,
highlights = config.highlights,
})
end
end
---@param bufnr integer
---@return fun()
local function create_debounced_highlight(bufnr)
local timer = nil ---@type table?
return function()
if timer then
timer:stop() ---@diagnostic disable-line: undefined-field
timer:close() ---@diagnostic disable-line: undefined-field
timer = nil
end
local t = vim.uv.new_timer()
if not t then
highlight_buffer(bufnr)
return
end
timer = t
t:start(
config.debounce_ms,
0,
vim.schedule_wrap(function()
if timer == t then
timer = nil
t:close()
end
highlight_buffer(bufnr)
end)
)
end
end
local function compute_highlight_groups()
local normal = vim.api.nvim_get_hl(0, { name = 'Normal' })
local diff_add = vim.api.nvim_get_hl(0, { name = 'DiffAdd' })
local diff_delete = vim.api.nvim_get_hl(0, { name = 'DiffDelete' })
local diff_added = resolve_hl('diffAdded')
local diff_removed = resolve_hl('diffRemoved')
local bg = normal.bg or 0x1e1e2e
local add_bg = diff_add.bg or 0x2e4a3a
local del_bg = diff_delete.bg or 0x4a2e3a
local add_fg = diff_added.fg or diff_add.fg or 0x80c080
local del_fg = diff_removed.fg or diff_delete.fg or 0xc08080
local blended_add = blend_color(add_bg, bg, 0.4)
local blended_del = blend_color(del_bg, bg, 0.4)
local blended_add_text = blend_color(add_fg, bg, 0.7)
local blended_del_text = blend_color(del_fg, bg, 0.7)
vim.api.nvim_set_hl(0, 'DiffsAdd', { default = true, bg = blended_add })
vim.api.nvim_set_hl(0, 'DiffsDelete', { default = true, bg = blended_del })
vim.api.nvim_set_hl(0, 'DiffsAddNr', { default = true, fg = add_fg, bg = blended_add })
vim.api.nvim_set_hl(0, 'DiffsDeleteNr', { default = true, fg = del_fg, bg = blended_del })
vim.api.nvim_set_hl(0, 'DiffsAddText', { default = true, bg = blended_add_text })
vim.api.nvim_set_hl(0, 'DiffsDeleteText', { default = true, bg = blended_del_text })
dbg('highlight groups: Normal.bg=#%06x DiffAdd.bg=#%06x diffAdded.fg=#%06x', bg, add_bg, add_fg)
dbg(
'DiffsAdd.bg=#%06x DiffsAddText.bg=#%06x DiffsAddNr.fg=#%06x',
blended_add,
blended_add_text,
add_fg
)
dbg('DiffsDelete.bg=#%06x DiffsDeleteText.bg=#%06x', blended_del, blended_del_text)
local diff_change = resolve_hl('DiffChange')
local diff_text = resolve_hl('DiffText')
vim.api.nvim_set_hl(0, 'DiffsDiffAdd', { bg = diff_add.bg })
vim.api.nvim_set_hl(0, 'DiffsDiffDelete', { fg = diff_delete.fg, bg = diff_delete.bg })
vim.api.nvim_set_hl(0, 'DiffsDiffChange', { bg = diff_change.bg })
vim.api.nvim_set_hl(0, 'DiffsDiffText', { bg = diff_text.bg })
end
local function init()
if initialized then
return
end
initialized = true
local opts = vim.g.diffs or {}
vim.validate({
debug = { opts.debug, 'boolean', true },
debounce_ms = { opts.debounce_ms, 'number', true },
hide_prefix = { opts.hide_prefix, 'boolean', true },
highlights = { opts.highlights, 'table', true },
})
if opts.highlights then
vim.validate({
['highlights.background'] = { opts.highlights.background, 'boolean', true },
['highlights.gutter'] = { opts.highlights.gutter, 'boolean', true },
['highlights.treesitter'] = { opts.highlights.treesitter, 'table', true },
['highlights.vim'] = { opts.highlights.vim, 'table', true },
['highlights.intra'] = { opts.highlights.intra, 'table', true },
})
if opts.highlights.treesitter then
vim.validate({
['highlights.treesitter.enabled'] = { opts.highlights.treesitter.enabled, 'boolean', true },
['highlights.treesitter.max_lines'] = {
opts.highlights.treesitter.max_lines,
'number',
true,
},
})
end
if opts.highlights.vim then
vim.validate({
['highlights.vim.enabled'] = { opts.highlights.vim.enabled, 'boolean', true },
['highlights.vim.max_lines'] = { opts.highlights.vim.max_lines, 'number', true },
})
end
if opts.highlights.intra then
vim.validate({
['highlights.intra.enabled'] = { opts.highlights.intra.enabled, 'boolean', true },
['highlights.intra.algorithm'] = {
opts.highlights.intra.algorithm,
function(v)
return v == nil or v == 'auto' or v == 'native' or v == 'vscode'
end,
"'auto', 'native', or 'vscode'",
},
['highlights.intra.max_lines'] = { opts.highlights.intra.max_lines, 'number', true },
})
end
end
if opts.fugitive then
vim.validate({
['fugitive.horizontal'] = {
opts.fugitive.horizontal,
function(v)
return v == false or type(v) == 'string'
end,
'string or false',
},
['fugitive.vertical'] = {
opts.fugitive.vertical,
function(v)
return v == false or type(v) == 'string'
end,
'string or false',
},
})
end
if opts.debounce_ms and opts.debounce_ms < 0 then
error('diffs: debounce_ms must be >= 0')
end
if
opts.highlights
and opts.highlights.treesitter
and opts.highlights.treesitter.max_lines
and opts.highlights.treesitter.max_lines < 1
then
error('diffs: highlights.treesitter.max_lines must be >= 1')
end
if
opts.highlights
and opts.highlights.vim
and opts.highlights.vim.max_lines
and opts.highlights.vim.max_lines < 1
then
error('diffs: highlights.vim.max_lines must be >= 1')
end
if
opts.highlights
and opts.highlights.intra
and opts.highlights.intra.max_lines
and opts.highlights.intra.max_lines < 1
then
error('diffs: highlights.intra.max_lines must be >= 1')
end
config = vim.tbl_deep_extend('force', default_config, opts)
log.set_enabled(config.debug)
compute_highlight_groups()
vim.api.nvim_create_autocmd('ColorScheme', {
callback = function()
compute_highlight_groups()
for bufnr, _ in pairs(attached_buffers) do
highlight_buffer(bufnr)
end
end,
})
vim.api.nvim_create_autocmd('WinClosed', {
callback = function(args)
local win = tonumber(args.match)
if win and diff_windows[win] then
diff_windows[win] = nil
end
end,
})
end
---@param bufnr? integer
function M.attach(bufnr)
init()
bufnr = bufnr or vim.api.nvim_get_current_buf()
if attached_buffers[bufnr] then
return
end
attached_buffers[bufnr] = true
dbg('attaching to buffer %d', bufnr)
local debounced = create_debounced_highlight(bufnr)
highlight_buffer(bufnr)
vim.api.nvim_create_autocmd({ 'TextChanged', 'TextChangedI' }, {
buffer = bufnr,
callback = debounced,
})
vim.api.nvim_create_autocmd('Syntax', {
buffer = bufnr,
callback = function()
dbg('syntax event, re-highlighting buffer %d', bufnr)
highlight_buffer(bufnr)
end,
})
vim.api.nvim_create_autocmd('BufReadPost', {
buffer = bufnr,
callback = function()
dbg('BufReadPost event, re-highlighting buffer %d', bufnr)
highlight_buffer(bufnr)
end,
})
vim.api.nvim_create_autocmd('BufWipeout', {
buffer = bufnr,
callback = function()
attached_buffers[bufnr] = nil
end,
})
end
---@param bufnr? integer
function M.refresh(bufnr)
bufnr = bufnr or vim.api.nvim_get_current_buf()
highlight_buffer(bufnr)
end
local DIFF_WINHIGHLIGHT = table.concat({
'DiffAdd:DiffsDiffAdd',
'DiffDelete:DiffsDiffDelete',
'DiffChange:DiffsDiffChange',
'DiffText:DiffsDiffText',
}, ',')
function M.attach_diff()
init()
local tabpage = vim.api.nvim_get_current_tabpage()
local wins = vim.api.nvim_tabpage_list_wins(tabpage)
local diff_wins = {}
for _, win in ipairs(wins) do
if vim.api.nvim_win_is_valid(win) and vim.wo[win].diff then
table.insert(diff_wins, win)
end
end
if #diff_wins == 0 then
return
end
for _, win in ipairs(diff_wins) do
vim.api.nvim_set_option_value('winhighlight', DIFF_WINHIGHLIGHT, { win = win })
diff_windows[win] = true
dbg('applied diff winhighlight to window %d', win)
end
end
function M.detach_diff()
for win, _ in pairs(diff_windows) do
if vim.api.nvim_win_is_valid(win) then
vim.api.nvim_set_option_value('winhighlight', '', { win = win })
end
diff_windows[win] = nil
end
end
---@return diffs.FugitiveConfig
function M.get_fugitive_config()
init()
return config.fugitive
end
return M