--- *mini.diff* Work with diff hunks

--- *MiniDiff*

---

--- MIT License Copyright (c) 2024 Evgeni Chasnovski

---

--- ==============================================================================

---

--- Features:

---

--- - Visualize difference between buffer text and its configurable reference

--- interactively (updates as you type). This is done per line showing whether

--- it is inside added, changed, or deleted part of difference (called hunk).

--- Visualization can be with customizable colored signs or line numbers.

---

--- - Special toggleable overlay view with more hunk details inside text area.

--- See |MiniDiff.toggle_overlay()|.

---

--- - Completely configurable per buffer source(s) of reference text used to keep

--- it up to date and define interactions with it. Can be array of sources which

--- are attempted to attach in order. See |MiniDiff-source-specification|.

--- By default uses Git source. See |MiniDiff.gen_source.git()|.

---

--- - Configurable mappings to manage diff hunks:

--- - Apply and reset hunks inside region (selected visually or with

--- a dot-repeatable operator).

--- - "Hunk range under cursor" textobject to be used as operator target.

--- - Navigate to first/previous/next/last hunk. See |MiniDiff.goto_hunk()|.

---

--- What it doesn't do:

---

--- - Provide functionality to work directly with Git outside of visualizing

--- and staging (applying) hunks with (default) Git source. In particular,

--- unstaging hunks is not supported. See |MiniDiff.gen_source.git()|.

---

--- Sources with more details:

--- - |MiniDiff-overview|

--- - |MiniDiff-source-specification|

--- - |MiniDiff-hunk-specification|

--- - |MiniDiff-diff-summary|

---

--- # Setup ~

---

--- This module needs a setup with `require('mini.diff').setup({})` (replace

--- `{}` with your `config` table). It will create global Lua table `MiniDiff`

--- which you can use for scripting or manually (with `:lua MiniDiff.*`).

---

--- See |MiniDiff.config| for `config` structure and default values.

---

--- You can override runtime config settings locally to buffer inside

--- `vim.b.minidiff_config` which should have same structure as

--- `MiniDiff.config`. See |mini.nvim-buffer-local-config| for more details.

---

--- # Comparisons ~

---

--- - 'lewis6991/gitsigns.nvim':

--- - Main inspiration for this module, so there are many similarities.

--- - Can display only Git hunks, while this module has extensible design.

--- - Provides more functionality to work with Git outside of hunks.

--- This module does not (by design).

---

--- # Highlight groups ~

---

--- * `MiniDiffSignAdd` - "add" hunk lines visualization.

--- * `MiniDiffSignChange` - "change" hunk lines visualization.

--- * `MiniDiffSignDelete` - "delete" hunk lines visualization.

--- * `MiniDiffOverAdd` - added buffer text shown in overlay.

--- * `MiniDiffOverChange` - changed reference text shown in overlay.

--- * `MiniDiffOverChangeBuf` - changed buffer text shown in overlay.

--- * `MiniDiffOverContext` - context of a change shown in reference overlay.

--- * `MiniDiffOverContextBuf` - context of a change shown in buffer overlay.

--- * `MiniDiffOverDelete` - deleted reference text shown in overlay.

---

--- To change any highlight group, modify it directly with |:highlight|.

---

--- # Disabling ~

---

--- To temporarily disable features without relying on |MiniDiff.disable()|,

--- set `vim.g.minidiff_disable` (globally) or `vim.b.minidiff_disable` (for

--- a buffer) to `true`. Considering high number of different scenarios and

--- customization intentions, writing exact rules for disabling module's

--- functionality is left to user.

--- See |mini.nvim-disabling-recipes| for common recipes.

--- # Diffs and hunks ~

---

--- The "diff" (short for "difference") is a result of computing how two text

--- strings differ from one another. This is done on per line basis, i.e. the

--- goal is to compute sequences of lines common to both files, interspersed

--- with groups of differing lines (called "hunks").

---

--- Although computing diff is a general concept (used on its own, in Git, etc.),

--- this module computes difference between current text in a buffer and some

--- reference text which is kept up to date specifically for that buffer.

--- For example, default reference text is computed as file content in Git index.

--- This can be customized in `config.source` (see |MiniDiff-source-specification|).

---

--- *MiniDiff-hunk-specification*

--- Hunk describes two sets (one from buffer text, one - from reference) of

--- consecutive lines which are different. In this module hunk is stored as

--- a table with the following fields:

---

--- - <buf_start> `(number)` - start of hunk buffer lines. First line is 1.

--- Can be 0 if first reference lines are deleted.

---

--- - <buf_count> `(number)` - number of consecutive buffer lines. Can be 0 in

--- case reference lines are deleted.

---

--- - <ref_start> `(number)` - start of hunk reference lines. First line is 1.

--- Can be 0 if lines are added before first reference line.

---

--- - <ref_count> `(number)` - number of consecutive reference lines. Can be 0 in

--- case buffer lines are added.

---

--- - <type> `(string)` - hunk type. Can be one of:

--- - "add" - lines are present in buffer but absent in reference.

--- - "change" - lines are present in both buffer and reference.

--- - "delete" - lines are absent in buffer but present in reference.

---

--- # Life cycle ~

---

--- - When entering proper (not already enabled, valid, showing text) buffer,

--- it is attempted to be enabled for diff processing.

--- - During enabling, attempt attaching the source. This should set up how

--- reference text is kept up to date.

--- - On every text change, diff computation is scheduled in debounced fashion

--- after customizable delay (200 ms by default).

--- - After the diff is computed, do the following:

--- - Update visualization based on configurable style: either by placing

--- colored text in sign column or coloring line numbers. Colors for both

--- styles are defined per hunk type in corresponding `MiniDiffSign*`

--- highlight group (see |MiniDiff|) and sign text for "sign" style can

--- be configured in `view.signs` of |MiniDiff.config|.

--- - Update overlay view (if it is enabled).

--- - Update `vim.b.minidiff_summary` and `vim.b.minidiff_summary_string`

--- buffer-local variables. These can be used, for example, in statusline.

--- *MiniDiff-update-event*

--- - Trigger `MiniDiffUpdated` `User` event. See |MiniDiff-diff-summary| for

--- example of how to use it.

---

--- Notes:

--- - Use |:edit| to reset (disable and re-enable) current buffer.

--- - To work with BOM bytes, set 'bomb' and have `ucs-bom` in 'fileencodings'.

---

--- # Overlay ~

---

--- Along with basic visualization, there is a special view called "overlay".

--- Although it is meant for temporary overview of diff details and can be

--- manually toggled via |MiniDiff.toggle_overlay()|, text can be changed with

--- overlay reacting accordingly.

---

--- It shows more diff details inside text area:

---

--- - Added buffer lines are highlighted with `MiniDiffOverAdd` highlight group.

---

--- - Deleted reference lines are shown as virtual lines and highlighted with

--- `MiniDiffOverDelete` highlight group.

---

--- - "Change" hunks with equal number of buffer/reference lines show "word diff".

--- This is usually the case when `options.linematch` is enabled (as by default).

--- Reference line is shown next to its buffer counterpart. Changed parts are

--- highlighted with `MiniDiffOverChange` and `MiniDiffOverChangeBuf` in reference

--- and buffer lines. The rest of lines have `MiniDiffOverContext`

--- and `MiniDiffOverContextBuf` highlighting.

---

--- Change with unequal number of buffer/reference lines is shown with reference

--- part as virtual lines highlighted with `MiniDiffOverChange` group.

--- Corresponding buffer lines are treated as context for the change and are

--- highlighted with `MiniDiffOverContextBuf` group.

---

--- Notes:

--- - Word diff has non-zero context width. This means if changed characters

--- are close enough, whole range between them is also colored. This usually

--- reduces visual noise.

--- - Virtual lines above line 1 (like deleted or changed lines) need manual

--- scroll to become visible (with |CTRL-Y|).

---

--- # Mappings ~

---

--- This module provides mappings for common actions with diffs, like:

--- - Apply and reset hunks.

--- - "Hunk range under cursor" textobject.

--- - Go to first/previous/next/last hunk range.

---

--- Examples:

--- - `vip` followed by `gh` / `gH` applies/resets hunks inside current paragraph.

--- Same can be achieved in operator form `ghip` / `gHip`, which has the

--- advantage of being dot-repeatable (see |single-repeat|).

--- - `gh_` / `gH_` applies/resets current line (even if it is not a full hunk).

--- - `ghgh` / `gHgh` applies/resets hunk range under cursor.

--- - `dgh` deletes hunk range under cursor.

--- - `[H` / `[h` / `]h` / `]H` navigate cursor to the first / previous / next / last

--- hunk range of the current buffer.

---

--- Mappings for some functionality are assumed to be done manually.

--- See |MiniDiff.operator()|.

---

--- # Buffer-local variables ~

--- *MiniDiff-diff-summary*

--- Each enabled buffer has the following buffer-local variables which can be

--- used in custom statusline to show an overview of hunks in current buffer:

---

--- - `vim.b.minidiff_summary` is a table with the following fields:

--- - `source_name` - name of the active source.

--- - `n_ranges` - number of hunk ranges (sequences of contiguous hunks).

--- - `add` - number of added lines.

--- - `change` - number of changed lines.

--- - `delete` - number of deleted lines.

---

--- - `vim.b.minidiff_summary_string` is a string representation of summary

--- with a fixed format. It is expected to be used as is. To achieve

--- different formatting, use `vim.b.minidiff_summary` to construct one.

--- The best way to do this is by overriding `vim.b.minidiff_summary_string`

--- in the callback for |MiniDiff-update-event| event: >lua

---

--- local format_summary = function(data)

--- local summary = vim.b[data.buf].minidiff_summary

--- local t = {}

--- if summary.add > 0 then table.insert(t, '+' .. summary.add) end

--- if summary.change > 0 then table.insert(t, '~' .. summary.change) end

--- if summary.delete > 0 then table.insert(t, '-' .. summary.delete) end

--- vim.b[data.buf].minidiff_summary_string = table.concat(t, ' ')

--- end

--- local au_opts = { pattern = 'MiniDiffUpdated', callback = format_summary }

--- vim.api.nvim_create_autocmd('User', au_opts)

--- <

---@tag MiniDiff-overview

---@alias __diff_buf_id number Target buffer identifier. Default: 0 for current buffer.

---@diagnostic disable:undefined-field

---@diagnostic disable:discard-returns

---@diagnostic disable:unused-local

---@diagnostic disable:cast-local-type

---@diagnostic disable:undefined-doc-name

---@diagnostic disable:luadoc-miss-type-name

-- Module definition ==========================================================

local MiniDiff = {}

local H = {}

--- Module setup

---

---@param config table|nil Module config table. See |MiniDiff.config|.

---

---@usage >lua

--- require('mini.diff').setup() -- use default config

--- -- OR

--- require('mini.diff').setup({}) -- replace {} with your config table

--- <

MiniDiff.setup = function(config)

-- Export module

_G.MiniDiff = MiniDiff

-- Setup config

config = H.setup_config(config)

-- Apply config

H.apply_config(config)

-- Define behavior

H.create_autocommands()

for _, buf_id in ipairs(vim.api.nvim_list_bufs()) do

H.auto_enable({ buf = buf_id })

end

-- Create default highlighting

H.create_default_hl()

end

--stylua: ignore

--- Module config

---

--- Default values:

---@eval return MiniDoc.afterlines_to_code(MiniDoc.current.eval_section)

---@text # View ~

---

--- `config.view` contains settings for how diff hunks are visualized.

--- Example of using custom signs: >lua

---

--- require('mini.diff').setup({

--- view = {

--- style = 'sign',

--- signs = { add = '+', change = '~', delete = '-' },

--- },

--- })

--- <

--- `view.style` is a string defining visualization style. Can be one of "sign"

--- (as a colored sign in a |sign-column|) or "number" (colored line number).

--- Default: "number" if |number| option is enabled, "sign" otherwise.

--- Note: with "sign" style it is usually better to have |signcolumn| always shown.

---

--- `view.signs` is a table with one or two character strings used as signs for

--- corresponding ("add", "change", "delete") hunks.

--- Default: all hunks use "▒" character resulting in a contiguous colored lines.

---

--- `view.priority` is a number with priority used for visualization and

--- overlay |extmarks|.

--- Default: 199 which is one less than `user` in |vim.hl.priorities| (on Neovim<0.11

--- see |vim.highlight.priorities|) to have higher priority than automated

--- extmarks but not as in user enabled ones.

---

--- *MiniDiff-source-specification*

--- # Source ~

---

--- `config.source` is a table with single source or array of them. Single source

--- defines how reference text is managed in a particular buffer. Sources in array

--- are attempted to attach in order; call |MiniDiff.disable()| if none attaches.

---

--- A single source table can have the following fields:

---

--- - <attach> `(function)` - callable which defines how and when reference text

--- is updated inside a particular buffer. It is used inside |MiniDiff.enable()|

--- with a buffer identifier as a single argument.

---

--- Should execute logic which results into calling |MiniDiff.set_ref_text()|

--- when reference text for buffer needs to be updated. Like inside callback

--- for an |autocommand| or file watcher (see |watch-file|).

---

--- For example, default Git source watches when ".git/index" file is changed

--- and computes reference text as the one from Git index for current file.

---

--- Can return `false` to indicate that attach has failed. If attach fail can

--- not be inferred immediately (for example, due to asynchronous execution),

--- should explicitly call |MiniDiff.fail_attch()| with appropriate arguments.

--- This is important to properly process array of sources.

---

--- No default value, should be always supplied.

---

--- - <name> `(string|nil)` - source name. String `"unknown"` is used if not supplied.

---

--- - <detach> `(function|nil)` - callable with cleanup action to be done when

--- buffer is disabled. It is called inside |MiniDiff.disable()| with a buffer

--- identifier as a single argument.

---

--- If not supplied, nothing is done during detaching.

---

--- - <apply_hunks> `(function|nil)` - callable which defines how hunks are applied.

--- It is called with buffer identifier as first argument and array of hunks

--- (see |MiniDiff-hunk-specification|) as second. It should eventually update

--- reference text: either by explicitly calling |MiniDiff.set_ref_text()| or

--- performing action triggering its call.

---

--- For example, default Git source computes patch based on the hunks and

--- applies it inside file's git repo.

---

--- If not supplied, applying hunks throws an error.

---

--- Default: a single |MiniDiff.gen_source.git()|.

---

--- # Delay ~

---

--- `config.delay` contains settings for delays in asynchronous processes.

---

--- `delay.text_change` is a number (in ms) defining how long to wait after latest

--- text change (in debounced fashion) before updating diff and visualization.

--- Default: 200.

---

--- # Mappings ~

---

--- `config.mappings` contains keys which are mapped during |MiniDiff.setup()|.

---

--- `mappings.apply` keys can be used to apply hunks inside visual/operator region.

--- What exactly "apply hunks" means depends on the source and its `apply_hunks()`.

--- For example, in default Git source it means stage hunks.

---

--- `mappings.reset` keys can be used to reset hunks inside visual/operator region.

--- Reset means replacing buffer text in region with corresponding reference text.

---

--- `mappings.textobject` keys define "hunk range under cursor" textobject

--- which can be used in Operator-pending mode as target for operator (like

--- |d|, |y|, apply/reset hunks, etc.). It is also set up in Visual mode if

--- keys do not conflict with `mappings.apply` and `mappings.reset`.

--- "Hunk range" is used in a sense that contiguous (back-to-back) hunks are

--- considered as parts of a same hunk range.

---

--- `mappings.goto_first` / `mappings.goto_prev` / `mappings.goto_next` /

--- `mappings.goto_last` keys can be used to navigate to first / previous / next /

--- last hunk range in the current buffer.

---

--- # Options ~

---

--- `config.options` contains various customization options.

---

--- `options.algorithm` is a string defining which diff algorithm to use.

--- Default: "histogram". See |vim.diff()| for possible values.

---

--- `options.indent_heuristic` is a boolean defining whether to use indent

--- heuristic for a (possibly) more naturally aligned hunks.

--- Default: `true`.

---

--- `options.linematch` is a number defining hunk size for which a second

--- stage diff is executed for a better aligned and more granular hunks.

--- Default: 60. See |vim.diff()| and 'diffopt' for more details.

---

--- `options.wrap_goto` is a boolean indicating whether to wrap around edges during

--- hunk navigation (with |MiniDiff.goto_hunk()| or `goto_*` mappings). Like if

--- cursor is after the last hunk, going "next" will put cursor on the first hunk.

--- Default: `false`.

MiniDiff.config = {

-- Options for how hunks are visualized

view = {

-- Visualization style. Possible values are 'sign' and 'number'.

-- Default: 'number' if line numbers are enabled, 'sign' otherwise.

style = vim.go.number and 'number' or 'sign',

-- Signs used for hunks with 'sign' view

signs = { add = '▒', change = '▒', delete = '▒' },

-- Priority of used visualization extmarks

priority = 199,

},

-- Source(s) for how reference text is computed/updated/etc

-- Uses content from Git index by default

source = nil,

-- Delays (in ms) defining asynchronous processes

delay = {

-- How much to wait before update following every text change

text_change = 200,

},

-- Module mappings. Use `''` (empty string) to disable one.

mappings = {

-- Apply hunks inside a visual/operator region

apply = 'gh',

-- Reset hunks inside a visual/operator region

reset = 'gH',

-- Hunk range textobject to be used inside operator

-- Works also in Visual mode if mapping differs from apply and reset

textobject = 'gh',

-- Go to hunk range in corresponding direction

goto_first = '[H',

goto_prev = '[h',

goto_next = ']h',

goto_last = ']H',

},

-- Various options

options = {

-- Diff algorithm. See `:h vim.diff()`.

algorithm = 'histogram',

-- Whether to use "indent heuristic". See `:h vim.diff()`.

indent_heuristic = true,

-- The amount of second-stage diff to align lines

linematch = 60,

-- Whether to wrap around edges during hunk navigation

wrap_goto = false,

},

}

--minidoc_afterlines_end

--- Enable diff processing in buffer

---

---@param buf_id __diff_buf_id

MiniDiff.enable = function(buf_id)

buf_id = H.validate_buf_id(buf_id)

-- Don't enable more than once

if H.is_buf_enabled(buf_id) or H.is_disabled(buf_id) then return end

-- Ensure buffer is loaded (to have up to date lines returned)

H.buf_ensure_loaded(buf_id)

-- Register enabled buffer with cached data for performance

H.update_buf_cache(buf_id)

-- Add buffer watchers

vim.api.nvim_buf_attach(buf_id, false, {

-- Called on every text change (`:h nvim_buf_lines_event`)

on_lines = function(_, _, _, from_line, _, to_line)

local buf_cache = H.cache[buf_id]

-- Properly detach if diffing is disabled

if buf_cache == nil then return true end

H.schedule_diff_update(buf_id, buf_cache.config.delay.text_change)

end,

-- Called when buffer content is changed outside of current session

on_reload = function() H.schedule_diff_update(buf_id, 0) end,

-- Called when buffer is unloaded from memory (`:h nvim_buf_detach_event`),

-- **including** `:edit` command

on_detach = function() MiniDiff.disable(buf_id) end,

})

-- Add buffer autocommands

H.setup_buf_autocommands(buf_id)

-- Try attaching source after all necessary watchers are set up. It is needed

-- to still have them set up if first source of many returned `false`.

local attach_output = H.get_active_source(H.cache[buf_id]).attach(buf_id)

if attach_output == false then MiniDiff.fail_attach(buf_id) end

end

--- Disable diff processing in buffer

---

---@param buf_id __diff_buf_id

MiniDiff.disable = function(buf_id)

buf_id = H.validate_buf_id(buf_id)

local buf_cache = H.cache[buf_id]

if buf_cache == nil then return end

H.cache[buf_id] = nil

pcall(vim.api.nvim_del_augroup_by_id, buf_cache.augroup)

vim.b[buf_id].minidiff_summary, vim.b[buf_id].minidiff_summary_string = nil, nil

H.clear_all_diff(buf_id)

pcall(H.get_active_source(buf_cache).detach, buf_id)

end

--- Toggle diff processing in buffer

---

--- Enable if disabled, disable if enabled.

---

---@param buf_id __diff_buf_id

MiniDiff.toggle = function(buf_id)

buf_id = H.validate_buf_id(buf_id)

if H.is_buf_enabled(buf_id) then return MiniDiff.disable(buf_id) end

return MiniDiff.enable(buf_id)

end

--- Toggle overlay view in buffer

---

---@param buf_id __diff_buf_id

MiniDiff.toggle_overlay = function(buf_id)

buf_id = H.validate_buf_id(buf_id)

local buf_cache = H.cache[buf_id]

if buf_cache == nil then H.error(string.format('Buffer %d is not enabled.', buf_id)) end

buf_cache.overlay = not buf_cache.overlay

H.clear_all_diff(buf_id)

H.schedule_diff_update(buf_id, 0)

end

--- Export hunks

---

--- Get and convert hunks from current/all buffers. Example of using it: >lua

---

--- -- Set quickfix list from all available hunks

--- vim.fn.setqflist(MiniDiff.export('qf'))

--- <

---@param format string Output format. Currently only `'qf'` value is supported.

---@param opts table|nil Options. Possible fields:

--- - <scope> `(string)` - scope defining from which buffers to use hunks.

--- One of "all" (all enabled buffers) or "current".

---

---@return table Result of export. Depends on the `format`:

--- - If "qf", an array compatible with |setqflist()| and |setloclist()|.

MiniDiff.export = function(format, opts)

opts = vim.tbl_deep_extend('force', { scope = 'all' }, opts or {})

if format == 'qf' then return H.export_qf(opts) end

H.error('`format` should be one of "qf".')

end

--- Get buffer data

---

---@param buf_id __diff_buf_id

---

---@return table|nil Table with buffer diff data or `nil` if buffer is not enabled.

--- Table has the following fields:

--- - <config> `(table)` - config used for this particular buffer.

--- - <hunks> `(table)` - array of hunks. See |MiniDiff-hunk-specification|.

--- - <overlay> `(boolean)` - whether an overlay view is shown.

--- - <ref_text> `(string|nil)` - current value of reference text. Lines are

--- separated with newline character (`'\n'`). Can be `nil` indicating that

--- reference text was not yet set (for example, if source did not yet react).

--- - <summary> `(table)` - overall diff summary. See |MiniDiff-diff-summary|.

MiniDiff.get_buf_data = function(buf_id)

buf_id = H.validate_buf_id(buf_id)

local buf_cache = H.cache[buf_id]

if buf_cache == nil then return nil end

return vim.deepcopy({

config = buf_cache.config,

hunks = buf_cache.hunks,

overlay = buf_cache.overlay,

ref_text = buf_cache.ref_text,

summary = buf_cache.summary,

})

end

--- Set reference text for the buffer

---

--- Note: this will call |MiniDiff.enable()| for target buffer if it is not

--- already enabled.

---

---@param buf_id __diff_buf_id

---@param text string|table New reference text. Either a string with `\n` used to

--- separate lines or array of lines. Use empty table to unset current

--- reference text (results into no hunks shown). Default: `{}`.

--- Note: newline character is appended at the end (if it is not there already)

--- for better diffs.

MiniDiff.set_ref_text = function(buf_id, text)

buf_id = H.validate_buf_id(buf_id)

if not (type(text) == 'table' or type(text) == 'string') then H.error('`text` should be either string or array.') end

if type(text) == 'table' then text = #text > 0 and table.concat(text, '\n') or nil end

-- Enable if not already enabled

if not H.is_buf_enabled(buf_id) then MiniDiff.enable(buf_id) end

if not H.is_buf_enabled(buf_id) then H.error('Can not set reference text for not enabled buffer.') end

-- Appending '\n' makes more intuitive diffs at end-of-file

if text ~= nil and string.sub(text, -1) ~= '\n' then text = text .. '\n' end

if text == nil then

H.clear_all_diff(buf_id)

vim.cmd('redraw')

end

-- Immediately update diff

H.cache[buf_id].ref_text = text

H.schedule_diff_update(buf_id, 0)

end

--- Generate builtin sources

---

--- This is a table with function elements. Call to actually get source.

--- Examples: >lua

---

--- local diff = require('mini.diff')

---

--- -- Single `save` source

--- diff.setup({ source = diff.gen_source.save() })

---

--- -- Multiple sources (attempted to attach in order)

--- diff.setup({ source = { diff.gen_source.git(), diff.gen_source.save() } })

--- <

MiniDiff.gen_source = {}

--- Git source

---

--- Default source. Uses file text from Git index as reference. This results in:

--- - "Add" hunks represent text present in current buffer, but not in index.

--- - "Change" hunks represent modified text already present in index.

--- - "Delete" hunks represent text deleted from index.

---

--- Applying hunks means staging, a.k.a adding to index.

--- Notes:

--- - Requires Git version at least 2.38.0.

--- - There is no capability for unstaging hunks. Use full Git client for that.

---

---@return table Source. See |MiniDiff-source-specification|.

MiniDiff.gen_source.git = function()

local attach = function(buf_id)

-- Try attaching to a buffer only once

if H.git_cache[buf_id] ~= nil then return false end

-- - Possibly resolve symlinks to get data from the original repo

local path = H.get_buf_realpath(buf_id)

if path == '' then return false end

H.git_cache[buf_id] = {}

H.git_start_watching_index(buf_id, path)

end

local detach = function(buf_id)

local cache = H.git_cache[buf_id]

H.git_cache[buf_id] = nil

H.git_invalidate_cache(cache)

end

local apply_hunks = function(buf_id, hunks)

local path_data = H.git_get_path_data(H.get_buf_realpath(buf_id))

if path_data == nil or path_data.rel_path == nil then return end

local patch = H.git_format_patch(buf_id, hunks, path_data)

H.git_apply_patch(path_data, patch)

end

return { name = 'git', attach = attach, detach = detach, apply_hunks = apply_hunks }

end

--- "Do nothing" source

---

--- Allows buffers to be enabled while not setting any reference text.

--- Use this if the goal is to rely on manual |MiniDiff.set_ref_text()| calls.

---

---@return table Source. See |MiniDiff-source-specification|.

MiniDiff.gen_source.none = function()

return { name = 'none', attach = function() end }

end

--- Latest save source

---

--- Uses text at latest save as the reference. This results into diff showing

--- difference after the latest save.

---

---@return table Source. See |MiniDiff-source-specification|.

MiniDiff.gen_source.save = function()

local augroups = {}

local attach = function(buf_id)

local augroup = vim.api.nvim_create_augroup('MiniDiffSourceSaveBuffer' .. buf_id, { clear = true })

augroups[buf_id] = augroup

local set_ref = function()

if vim.bo[buf_id].modified then return end

MiniDiff.set_ref_text(buf_id, H.get_buftext(buf_id))

end

-- Autocommand are more efficient than file watcher as it doesn't read disk

local au_opts = { group = augroup, buffer = buf_id, callback = set_ref, desc = 'Set reference text after save' }

vim.api.nvim_create_autocmd({ 'BufWritePost', 'FileChangedShellPost' }, au_opts)

set_ref()

end

local detach = function(buf_id) pcall(vim.api.nvim_del_augroup_by_id, augroups[buf_id]) end

return { name = 'save', attach = attach, detach = detach }

end

--- Perform action on hunks in region

---

--- Compute hunks inside a target region (even for hunks only partially inside it)

--- and perform apply/reset/yank operation on them.

---

--- The "yank" action yanks all reference lines of target hunks into

--- a specified register (should be one of |registers|).

---

--- Notes:

--- - Whether hunk is inside a region is computed based on position of its

--- buffer lines.

--- - If "change" or "delete" is only partially inside a target region, all

--- reference lines are used in computed "intersection" hunk.

---

--- Used directly in `config.mappings.apply` and `config.mappings.reset`.

--- Usually there is no need to use this function manually.

--- See |MiniDiff.operator()| for how to set up a mapping for "yank".

---

---@param buf_id __diff_buf_id

---@param action string One of "apply", "reset", "yank".

---@param opts table|nil Options. Possible fields:

--- - <line_start> `(number)` - start line of the region. Default: 1.

--- - <line_end> `(number)` - start line of the region. Default: last buffer line.

--- - <register> `(string)` - register to yank reference lines into.

--- Default: |v:register|.

MiniDiff.do_hunks = function(buf_id, action, opts)

buf_id = H.validate_buf_id(buf_id)

local buf_cache = H.cache[buf_id]

if buf_cache == nil then H.error(string.format('Buffer %d is not enabled.', buf_id)) end

if type(buf_cache.ref_text) ~= 'string' then H.error(string.format('Buffer %d has no reference text.', buf_id)) end

if not (action == 'apply' or action == 'reset' or action == 'yank') then

H.error('`action` should be one of "apply", "reset", "yank".')

end

local default_opts = { line_start = 1, line_end = vim.api.nvim_buf_line_count(buf_id), register = vim.v.register }

opts = vim.tbl_deep_extend('force', default_opts, opts or {})

local line_start, line_end = H.validate_target_lines(buf_id, opts.line_start, opts.line_end)

if type(opts.register) ~= 'string' then H.error('`opts.register` should be string.') end

local hunks = H.get_hunks_in_range(buf_cache.hunks, line_start, line_end)

if #hunks == 0 then return H.notify('No hunks to ' .. action, 'INFO') end

if action == 'apply' then H.get_active_source(buf_cache).apply_hunks(buf_id, hunks) end

if action == 'reset' then H.reset_hunks(buf_id, hunks) end

if action == 'yank' then H.yank_hunks_ref(buf_cache.ref_text, hunks, opts.register) end

end

--- Go to hunk range in current buffer

---

---@param direction string One of "first", "prev", "next", "last".

---@param opts table|nil Options. A table with fields:

--- - <n_times> `(number)` - Number of times to advance. Default: |v:count1|.

--- - <line_start> `(number)` - Line number to start from for directions

--- "prev" and "next". Default: cursor line.

--- - <wrap> `(boolean)` - Whether to wrap around edges.

--- Default: `options.wrap` value of the config.

MiniDiff.goto_hunk = function(direction, opts)

local buf_id = vim.api.nvim_get_current_buf()

local buf_cache = H.cache[buf_id]

if buf_cache == nil then H.error(string.format('Buffer %d is not enabled.', buf_id)) end

if not vim.tbl_contains({ 'first', 'prev', 'next', 'last' }, direction) then

H.error('`direction` should be one of "first", "prev", "next", "last".')

end

local default_wrap = buf_cache.config.options.wrap_goto

local default_opts = { n_times = vim.v.count1, line_start = vim.fn.line('.'), wrap = default_wrap }

opts = vim.tbl_deep_extend('force', default_opts, opts or {})

if not (type(opts.n_times) == 'number' and opts.n_times >= 1) then

H.error('`opts.n_times` should be positive number.')

end

if type(opts.line_start) ~= 'number' then H.error('`opts.line_start` should be number.') end

if type(opts.wrap) ~= 'boolean' then H.error('`opts.wrap` should be boolean.') end

-- Prepare ranges to iterate.

local ranges = H.get_contiguous_hunk_ranges(buf_cache.hunks)

if #ranges == 0 then return H.notify('No hunks to go to', 'INFO') end

-- Iterate

local res_ind, did_wrap = H.iterate_hunk_ranges(ranges, direction, opts)

if res_ind == nil then return H.notify('No hunk ranges in direction ' .. vim.inspect(direction), 'INFO') end

local res_line = ranges[res_ind].from

if did_wrap then H.notify('Wrapped around edge in direction ' .. vim.inspect(direction), 'INFO') end

-- Add to jumplist

vim.cmd([[normal! m']])

-- Jump

local _, col = vim.fn.getline(res_line):find('^%s*')

vim.api.nvim_win_set_cursor(0, { res_line, col })

-- Open just enough folds

vim.cmd('normal! zv')

end

--- Perform action over region

---

--- Perform action over region defined by marks. Used in mappings.

---

--- Example of a mapping to yank reference lines of hunk range under cursor

--- (assuming default 'config.mappings.textobject'): >lua

---

--- local rhs = function() return MiniDiff.operator('yank') .. 'gh' end

--- vim.keymap.set('n', 'ghy', rhs, { expr = true, remap = true })

--- <

---@param mode string One of "apply", "reset", "yank", or the ones used in |g@|.

MiniDiff.operator = function(mode)

local buf_id = vim.api.nvim_get_current_buf()

if H.is_disabled(buf_id) then return '' end

if mode == 'apply' or mode == 'reset' or mode == 'yank' then

H.operator_cache = { action = mode, win_view = vim.fn.winsaveview(), register = vim.v.register }

vim.o.operatorfunc = 'v:lua.MiniDiff.operator'

return 'g@'

end

local cache = H.operator_cache

-- NOTE: Using `[` / `]` marks also works in Visual mode as because it is

-- executed as part of `g@`, which treats visual selection as a result of

-- Operator-pending mode mechanics (for which visual selection is allowed to

-- define motion/textobject). The downside is that it sets 'operatorfunc',

-- but the upside is that it is "dot-repeatable" (for relative selection).

local opts = { line_start = vim.fn.line("'["), line_end = vim.fn.line("']"), register = cache.register }

if opts.line_end < opts.line_start then return H.notify('Not a proper textobject', 'INFO') end

MiniDiff.do_hunks(buf_id, cache.action, opts)

-- Restore window view for "apply" (as buffer text should not have changed)

if cache.action == 'apply' and cache.win_view ~= nil then

vim.fn.winrestview(cache.win_view)

-- NOTE: Restore only once because during dot-repeat it is not up to date

cache.win_view = nil

end

return ''

end

--- Select hunk range textobject

---

--- Selects all contiguous lines adjacent to cursor line which are in any (not

--- necessarily same) hunk (if cursor line itself is in hunk).

--- Used in default mappings.

MiniDiff.textobject = function()

local buf_id = vim.api.nvim_get_current_buf()

local buf_cache = H.cache[buf_id]

if buf_cache == nil or H.is_disabled(buf_id) then H.error('Current buffer is not enabled.') end

-- Get hunk range under cursor

local cur_line = vim.fn.line('.')

local regions, cur_region = H.get_contiguous_hunk_ranges(buf_cache.hunks), nil

for _, r in ipairs(regions) do

if r.from <= cur_line and cur_line <= r.to then cur_region = r end

end

if cur_region == nil then return H.notify('No hunk range under cursor', 'INFO') end

-- Select target region

local is_visual = vim.tbl_contains({ 'v', 'V', '\22' }, vim.fn.mode())

if is_visual then vim.cmd('normal! \27') end

vim.cmd(string.format('normal! %dGV%dG', cur_region.from, cur_region.to))

end

--- Indicate source attach fail

---

--- Try to attach next source; if there is none - call |MiniDiff.disable()|.

---

---@param buf_id integer Buffer identifier for which attach has failed.

MiniDiff.fail_attach = function(buf_id)

buf_id = H.validate_buf_id(buf_id)

-- Do nothing if there was no attempt to enable

local buf_cache = H.cache[buf_id]

if buf_cache == nil then return end

-- If no next source, disable buffer without calling any of `detach`

if buf_cache.source_id >= #buf_cache.source then

H.cache[buf_id].source_id = math.huge

return MiniDiff.disable(buf_id)

end

-- Try attaching next source

buf_cache.source_id = buf_cache.source_id + 1

local attach_output = H.get_active_source(H.cache[buf_id]).attach(buf_id)

if attach_output == false then MiniDiff.fail_attach(buf_id) end

end

-- Helper data ================================================================

-- Module default config

H.default_config = MiniDiff.config

H.default_source = { MiniDiff.gen_source.git() }

-- Timers

H.timer_diff_update = vim.loop.new_timer()

-- Namespaces per highlighter name

H.ns_id = {

viz = vim.api.nvim_create_namespace('MiniDiffViz'),

overlay = vim.api.nvim_create_namespace('MiniDiffOverlay'),

}

-- Cache of buffers waiting for debounced diff update

H.bufs_to_update = {}

-- Cache per enabled buffer

H.cache = {}

-- Cache per buffer for attached `git` source

H.git_cache = {}

-- Cache for operator

H.operator_cache = {}

-- Common extmark data for supported styles

--stylua: ignore

H.style_extmark_data = {

sign = { hl_group_prefix = 'MiniDiffSign', field = 'sign_hl_group' },

number = { hl_group_prefix = 'MiniDiffSign', field = 'number_hl_group' },

}

-- Suffix for overlay virtual lines to be highlighted as full line

H.overlay_suffix = string.rep(' ', vim.o.columns)

-- Flag for whether to invalidate extmarks

H.extmark_invalidate = vim.fn.has('nvim-0.10') == 1 and true or nil

-- Flag for whether to handle virtual lines overflow

H.extmark_virt_lines_overflow = vim.fn.has('nvim-0.11') == 1 and 'scroll' or nil

-- Permanent `vim.diff()` options

H.vimdiff_opts = { result_type = 'indices', ctxlen = 0, interhunkctxlen = 0 }

-- Options for `vim.diff()` during word diff. Use `interhunkctxlen = 4` to

-- reduce noisiness (chosen as slightly less than average English word length)

--stylua: ignore

H.worddiff_opts = {

algorithm = 'minimal', result_type = 'indices',

ctxlen = 0, interhunkctxlen = 4,

indent_heuristic = false, linematch = 0

}

-- BOM bytes prepended to buffer text if 'bomb' is enabled. See `:h bom-bytes`.

--stylua: ignore

H.bom_bytes = {

['utf-8'] = string.char(0xef, 0xbb, 0xbf),

['utf-16be'] = string.char(0xfe, 0xff),

['utf-16'] = string.char(0xfe, 0xff),

['utf-16le'] = string.char(0xff, 0xfe),

-- In 'fileencoding', 'utf-32' is transformed into 'ucs-4'

['utf-32be'] = string.char(0x00, 0x00, 0xfe, 0xff),

['ucs-4be'] = string.char(0x00, 0x00, 0xfe, 0xff),

['utf-32'] = string.char(0x00, 0x00, 0xfe, 0xff),

['ucs-4'] = string.char(0x00, 0x00, 0xfe, 0xff),

['utf-32le'] = string.char(0xff, 0xfe, 0x00, 0x00),

['ucs-4le'] = string.char(0xff, 0xfe, 0x00, 0x00),

}

-- Helper functionality =======================================================

-- Settings -------------------------------------------------------------------

H.setup_config = function(config)

H.check_type('config', config, 'table', true)

config = vim.tbl_deep_extend('force', vim.deepcopy(H.default_config), config or {})

H.check_type('view', config.view, 'table')

H.check_type('view.style', config.view.style, 'string')

H.check_type('view.signs', config.view.signs, 'table')

H.check_type('view.signs.add', config.view.signs.add, 'string')

H.check_type('view.signs.change', config.view.signs.change, 'string')

H.check_type('view.signs.delete', config.view.signs.delete, 'string')

H.check_type('view.priority', config.view.priority, 'number')

H.check_type('source', config.source, 'table', true)

H.check_type('delay', config.delay, 'table')

H.check_type('delay.text_change', config.delay.text_change, 'number')

H.check_type('mappings', config.mappings, 'table')

H.check_type('mappings.apply', config.mappings.apply, 'string')

H.check_type('mappings.reset', config.mappings.reset, 'string')

H.check_type('mappings.textobject', config.mappings.textobject, 'string')

H.check_type('mappings.goto_first', config.mappings.goto_first, 'string')

H.check_type('mappings.goto_prev', config.mappings.goto_prev, 'string')

H.check_type('mappings.goto_next', config.mappings.goto_next, 'string')

H.check_type('mappings.goto_last', config.mappings.goto_last, 'string')

H.check_type('options', config.options, 'table')

H.check_type('options.algorithm', config.options.algorithm, 'string')

H.check_type('options.indent_heuristic', config.options.indent_heuristic, 'boolean')

H.check_type('options.linematch', config.options.linematch, 'number')

H.check_type('options.wrap_goto', config.options.wrap_goto, 'boolean')