-- Copyright 2007-2022 Mitchell. See LICENSE.

local M = ui.find

--[[ This comment is for LuaDoc.
---
-- Textadept's Find & Replace pane.
-- @field find_entry_text (string)
--   The text in the "Find" entry.
-- @field replace_entry_text (string)
--   The text in the "Replace" entry.
--   When searching for text in a directory of files, this is the current file and directory filter.
-- @field match_case (bool)
--   Match search text case sensitively.
--   The default value is `false`.
-- @field whole_word (bool)
--   Match search text only when it is surrounded by non-word characters in searches.
--   The default value is `false`.
-- @field regex (bool)
--   Interpret search text as a Regular Expression.
--   The default value is `false`.
-- @field in_files (bool)
--   Find search text in a directory of files.
--   The default value is `false`.
-- @field incremental (bool)
--   Find search text incrementally as it is typed.
--   The default value is `false`.
-- @field find_label_text (string, Write-only)
--   The text of the "Find" label.
--   This is primarily used for localization.
-- @field replace_label_text (string, Write-only)
--   The text of the "Replace" label.
--   This is primarily used for localization.
-- @field find_next_button_text (string, Write-only)
--   The text of the "Find Next" button.
--   This is primarily used for localization.
-- @field find_prev_button_text (string, Write-only)
--   The text of the "Find Prev" button.
--   This is primarily used for localization.
-- @field replace_button_text (string, Write-only)
--   The text of the "Replace" button.
--   This is primarily used for localization.
-- @field replace_all_button_text (string, Write-only)
--   The text of the "Replace All" button.
--   This is primarily used for localization.
-- @field match_case_label_text (string, Write-only)
--   The text of the "Match case" label.
--   This is primarily used for localization.
-- @field whole_word_label_text (string, Write-only)
--   The text of the "Whole word" label.
--   This is primarily used for localization.
-- @field regex_label_text (string, Write-only)
--   The text of the "Regex" label.
--   This is primarily used for localization.
-- @field in_files_label_text (string, Write-only)
--   The text of the "In files" label.
--   This is primarily used for localization.
-- @field entry_font (string, Write-only)
--   The font to use in the "Find" and "Replace" entries in "name size" format.
--   The default value is system-dependent.
-- @field active (boolean)
--   Whether or not the Find & Replace pane is active.
-- @field highlight_all_matches (boolean)
--   Whether or not to highlight all occurrences of found text in the current buffer.
--   The default value is `false`.
-- @field show_filenames_in_progressbar (boolean)
--   Whether to show filenames in the find in files search progressbar.
--   This can be useful for determining whether or not custom filters are working as expected.
--   Showing filenames can slow down searches on computers with really fast SSDs.
--   The default value is `true`.
-- @field INDIC_FIND (number)
--   The find results highlight indicator number.
-- @field _G.events.FIND_RESULT_FOUND (string)
--   Emitted when a result is found. It is selected and has been scrolled into view.
--   Arguments:
--
--   * _`find_text`_: The text originally searched for.
-- @field _G.events.FIND_WRAPPED (string)
--   Emitted when a text search wraps (passes through the beginning of the buffer), either
--   from bottom to top (when searching for a next occurrence), or from top to bottom (when
--   searching for a previous occurrence).
--   This is useful for implementing a more visual or audible notice when a search wraps in
--   addition to the statusbar message.
module('ui.find')]]

local _L = _L
M.find_label_text, M.replace_label_text = _L['Find:'], _L['Replace:']
M.find_next_button_text = not CURSES and _L['Find Next'] or _L['[Next]']
M.find_prev_button_text = not CURSES and _L['Find Prev'] or _L['[Prev]']
M.replace_button_text = not CURSES and _L['Replace'] or _L['[Replace]']
M.replace_all_button_text = not CURSES and _L['Replace All'] or _L['[All]']
M.match_case_label_text = not CURSES and _L['Match case'] or _L['Case(F1)']
M.whole_word_label_text = not CURSES and _L['Whole word'] or _L['Word(F2)']
M.regex_label_text = not CURSES and _L['Regex'] or _L['Regex(F3)']
M.in_files_label_text = not CURSES and _L['In files'] or _L['Files(F4)']
M.highlight_all_matches = false
M.show_filenames_in_progressbar = true

M.INDIC_FIND = _SCINTILLA.next_indic_number()

-- Events.
local find_events = {'find_result_found', 'find_wrapped'}
for _, v in ipairs(find_events) do events[v:upper()] = v end

-- When finding in files, note the current view since results are shown in a split view. Jumping
-- between results should be done in the original view.
local preferred_view

---
-- Map of directory paths to filters used in `ui.find.find_in_files()`.
-- This table is updated when the user manually specifies a filter in the "Filter" entry during
-- an "In files" search.
-- @class table
-- @name find_in_files_filters
-- @see find_in_files
M.find_in_files_filters = {}

-- Keep track of find text and found text so that "replace all" works as expected during a find
-- session ("replace all" with selected text normally does "replace in selection"). Also track
-- find text for incremental find (if text has changed, the user is still typing; if text is
-- the same, the user clicked "Find Next" or "Find Prev"). Keep track of repl_text for non-"In
-- files" in order to restore it from filter text as necessary.
local find_text, found_text, repl_text = nil, nil, ui.find.replace_entry_text

-- Returns a reasonable initial directory for use with Find in Files.
local function ff_dir()
  return io.get_project_root() or (buffer.filename or ''):match('^.+[/\\]') or lfs.currentdir()
end

local orig_focus = M.focus
---
-- Displays and focuses the Find & Replace Pane.
-- @param options Optional table of `ui.find` field options to initially set.
-- @name focus
function M.focus(options)
  local already_in_files = M.in_files
  if not assert_type(options, 'table/nil', 1) then options = {} end
  if not options.in_files then options.in_files = false end -- reset
  if not options.incremental then options.incremental = false end -- reset
  for k, v in pairs(options) do M[k] = v end
  M.replace_label_text = not M.in_files and _L['Replace:'] or _L['Filter:']
  if M.in_files then
    if not already_in_files then repl_text = M.replace_entry_text end -- save
    local filter = M.find_in_files_filters[ff_dir()] or lfs.default_filter
    M.replace_entry_text = type(filter) == 'string' and filter or table.concat(filter, ',')
  elseif M.replace_entry_text ~= repl_text then
    M.replace_entry_text = repl_text -- restore
  end
  orig_focus()
end

-- Returns a bit-mask of search flags to use in Scintilla search functions based on the checkboxes
-- in the find box.
-- The "Find in Files" flag is unused by Scintilla, but used by Textadept.
-- @return search flag bit-mask
local function get_flags()
  return (M.match_case and buffer.FIND_MATCHCASE or 0) |
    (M.whole_word and buffer.FIND_WHOLEWORD or 0) | (M.regex and buffer.FIND_REGEXP or 0) |
    (M.in_files and 1 << 31 or 0)
end

-- Returns whether or not the given buffer is a files found buffer.
local function is_ff_buf(buf) return buf._type == _L['[Files Found Buffer]'] end

-- Clears highlighted match indicators.
local function clear_highlighted_matches()
  buffer.indicator_current = M.INDIC_FIND
  buffer:indicator_clear_range(1, buffer.length)
end
events.connect(events.KEYPRESS, function(code)
  if keys.KEYSYMS[code] ~= 'esc' or is_ff_buf(buffer) then return end
  clear_highlighted_matches()
end, 1)

local incremental_orig_pos
-- Finds and selects text in the current buffer.
-- @param text The text to find.
-- @param next Flag indicating whether or not the search direction is forward.
-- @param flags Search flags. This is a bit-mask of 4 flags: `buffer.FIND_MATCHCASE`,
--   `buffer.FIND_WHOLEWORD`, `buffer.FIND_REGEXP`, and 1 << 31 (in files), each joined with
--   binary OR. If `nil`, this is determined based on the checkboxes in the find box.
-- @param no_wrap Flag indicating whether or not the search will not wrap.
-- @param wrapped Utility flag indicating whether or not the search has wrapped for displaying
--   useful statusbar information. This flag is used and set internally, and should not be
--   set otherwise.
-- @return position of the found text or `-1`
local function find(text, next, flags, no_wrap, wrapped)
  -- Note: cannot use assert_type(), as event errors are handled silently.
  if text == '' then return end
  if not flags then flags = get_flags() end
  if flags >= 1 << 31 then
    M.find_in_files() -- performed here
    return
  end
  local first_visible_line = view.first_visible_line -- for 'no results found'
  if not is_ff_buf(buffer) then clear_highlighted_matches() end

  if M.incremental and not wrapped then
    local pos = buffer.current_pos
    if type(M.incremental) == 'boolean' then
      -- Starting a new incremental search, anchor at current pos.
      M.incremental, incremental_orig_pos = pos, pos
    elseif text == find_text then
      -- "Find Next" or "Find Prev" clicked, anchor at new current pos.
      M.incremental = buffer:position_relative(pos, next and 1 or -1)
    end
    buffer:goto_pos(M.incremental or 1)
  elseif not M.incremental then
    incremental_orig_pos = nil
  end

  -- If text is selected, assume it is from the current search and move the caret appropriately
  -- for the next search.
  buffer:goto_pos(next and buffer.selection_end or buffer.selection_start)

  -- Scintilla search.
  buffer:search_anchor()
  local f = next and buffer.search_next or buffer.search_prev
  local pos = f(buffer, flags, text)
  view:ensure_visible_enforce_policy(buffer:line_from_position(pos))
  view:scroll_range(buffer.anchor, buffer.current_pos)
  if pos ~= -1 then events.emit(events.FIND_RESULT_FOUND, text) end
  -- Track find text and found text for "replace all" and incremental find.
  find_text, found_text = text, buffer:get_sel_text()
  repl_text = ui.find.replace_entry_text -- save for ui.find.focus()

  -- If nothing was found, wrap the search.
  if pos == -1 and not no_wrap then
    local anchor = buffer.anchor
    buffer:goto_pos(next and 1 or buffer.length + 1)
    events.emit(events.FIND_WRAPPED)
    pos = find(text, next, flags, true, true)
    if pos == -1 then
      ui.statusbar_text = _L['No results found']
      view.first_visible_line = first_visible_line
      buffer:goto_pos(incremental_orig_pos or anchor)
    end
  end

  return pos
end
events.connect(events.FIND, find)
events.connect(events.FIND_TEXT_CHANGED, function()
  if not M.incremental then return end
  return events.emit(events.FIND, M.find_entry_text, true) -- refresh
end)
events.connect(events.FIND_RESULT_FOUND, function(text)
  -- Count and optionally highlight all occurrences.
  local count, current = 0, 1
  buffer.search_flags = get_flags()
  buffer:target_whole_document()
  while buffer:search_in_target(text) ~= -1 do
    local s, e = buffer.target_start, buffer.target_end
    if s == e then e = e + 1 end -- prevent loops for zero-length results
    if M.highlight_all_matches and e - s > 1 and not is_ff_buf(buffer) then
      buffer:indicator_fill_range(s, e - s)
    end
    buffer:set_target_range(e, buffer.length + 1)
    count = count + 1
    if s == buffer.current_pos then current = count end
  end
  ui.statusbar_text = string.format('%s %d/%d', _L['Match'], current, count)
  -- For regex searches, `buffer.tag` was clobbered. It needs to be filled in again for any
  -- subsequent replace operations that need it.
  if ui.find.regex then
    buffer:set_target_range(buffer.selection_start, buffer.length + 1)
    buffer:search_in_target(text)
  end
end)
events.connect(events.FIND_WRAPPED, function() ui.statusbar_text = _L['Search wrapped'] end)

---
-- Searches directory *dir* or the user-specified directory for files that match search text
-- and search options (subject to optional filter *filter*), and prints the results to a buffer
-- titled "Files Found", highlighting found text.
-- Use the `find_entry_text`, `match_case`, `whole_word`, and `regex` fields to set the search
-- text and option flags, respectively.
-- A filter determines which files to search in, with the default filter being
-- `ui.find.find_in_files_filters[dir]` (if it exists) or `lfs.default_filter`. A filter consists
-- of Lua patterns that match file and directory paths to include or exclude. Patterns are
-- inclusive by default. Exclusive patterns begin with a '!'. If no inclusive patterns are given,
-- any filename is initially considered. As a convenience, file extensions can be specified
-- literally instead of as a Lua pattern (e.g. '.lua' vs. '%.lua$'), and '/' also matches the
-- Windows directory separator ('[/\\]' is not needed). If *filter* is `nil`, the filter from
-- the `ui.find.find_in_files_filters` table for *dir* is used. If that filter does not exist,
-- `lfs.default_filter` is used.
-- @param dir Optional directory path to search. If `nil`, the user is prompted for one.
-- @param filter Optional filter for files and directories to exclude. The default value is
--   `lfs.default_filter` unless a filter for *dir* is defined in `ui.find.find_in_files_filters`.
-- @see find_in_files_filters
-- @name find_in_files
function M.find_in_files(dir, filter)
  if not assert_type(dir, 'string/nil', 1) then
    dir = ui.dialogs.fileselect{
      title = _L['Select Directory'], select_only_directories = true, with_directory = ff_dir()
    }
    if not dir then return end
  end
  if not assert_type(filter, 'string/table/nil', 2) then
    if M.replace_entry_text ~= repl_text then
      -- Update stored filter.
      local t = {}
      for patt in M.replace_entry_text:gmatch('[^,]+') do t[#t + 1] = patt end
      M.find_in_files_filters[dir], M.find_in_files_filters[ff_dir()] = t, t
    end
    filter = M.find_in_files_filters[dir] or lfs.default_filter
  end

  if buffer._type ~= _L['[Files Found Buffer]'] then preferred_view = view end
  ui.silent_print = false
  ui._print(_L['[Files Found Buffer]'],
    string.format('%s %s\n%s %s\n%s %s', _L['Find:']:gsub('_', ''), M.find_entry_text,
      _L['Directory:'], dir, _L['Filter:']:gsub('_', ''),
      type(filter) == 'string' and filter or table.concat(filter, ',')))
  buffer.indicator_current = M.INDIC_FIND

  -- Determine which files to search.
  local filenames, utf8_filenames = {}, {}
  for filename in lfs.walk(dir, filter) do
    filenames[#filenames + 1] = filename
    utf8_filenames[#utf8_filenames + 1] = filename:iconv('UTF-8', _CHARSET)
  end

  -- Perform the search in a temporary buffer and print results.
  local orig_buffer, buffer = buffer, buffer.new()
  view:goto_buffer(orig_buffer)
  buffer.code_page = 0 -- default is UTF-8
  buffer.search_flags = get_flags()
  local text, i, found, show_names = M.find_entry_text, 1, false, M.show_filenames_in_progressbar
  local stopped = ui.dialogs.progressbar({
    title = string.format('%s: %s', _L['Find in Files']:gsub('_', ''), text),
    text = show_names and utf8_filenames[i], stoppable = true,
    width = not show_names and not CURSES and 400
  }, function()
    local f = io.open(filenames[i], 'rb')
    buffer:set_text(f:read('a'))
    f:close()
    local binary = nil -- determine lazily for performance reasons
    buffer:target_whole_document()
    while buffer:search_in_target(text) ~= -1 do
      found = true
      if binary == nil then binary = buffer:text_range(1, 65536):find('\0') end
      if binary then
        _G.buffer:add_text(string.format('%s:1:%s\n', utf8_filenames[i], _L['Binary file matches.']))
        break
      end
      local line_num = buffer:line_from_position(buffer.target_start)
      local line = buffer:get_line(line_num)
      _G.buffer:add_text(string.format('%s:%d:%s', utf8_filenames[i], line_num, line))
      local pos = _G.buffer.current_pos - #line + buffer.target_start -
        buffer:position_from_line(line_num)
      _G.buffer:indicator_fill_range(pos, buffer.target_end - buffer.target_start)
      if not line:find('\n$') then _G.buffer:add_text('\n') end
      buffer:set_target_range(buffer.target_end, buffer.length + 1)
    end
    buffer:clear_all()
    buffer:empty_undo_buffer()
    view:scroll_caret() -- [Files Found Buffer]
    i = i + 1
    if i > #filenames then return nil end
    return i * 100 / #filenames, show_names and utf8_filenames[i] or nil
  end)
  buffer:close(true) -- temporary buffer
  local status = stopped and _L['Find in Files aborted'] or not found and _L['No results found']
  ui._print(_L['[Files Found Buffer]'], status and status .. '\n' or '')
end

local P, V, C, upper, lower = lpeg.P, lpeg.V, lpeg.C, string.upper, string.lower
local esc = {b = '\b', f = '\f', n = '\n', r = '\r', t = '\t', v = '\v'}
local re_patt = lpeg.Cs(P{
  (V('text') + V('u') + V('l') + V('U') + V('L') + V('esc'))^1,
  text = (1 - '\\' * lpeg.S('uUlLEbfnrtv'))^1, -- LuaFormatter
  u = '\\u' * C(1) / upper, l = '\\l' * C(1) / lower,
  U = P('\\U') / '' * (V('text') / upper + V('u') + V('l'))^0 * V('E')^-1,
  L = P('\\L') / '' * (V('text') / lower + V('u') + V('l'))^0 * V('E')^-1, -- LuaFormatter
  E = P('\\E') / '', esc = '\\' * C(1) / esc
})
-- Returns string *text* with the following sequences unescaped:
-- * "\uXXXX" sequences replaced with the equivalent UTF-8 character.
-- * "\d" sequences replaced with the text of capture number *d* from the regular expression
--   (or the entire match for *d* = 0).
-- * "\U" and "\L" sequences convert everything up to the next "\U", "\L", or "\E" to uppercase
--   and lowercase, respectively.
-- * "\u" and "\l" sequences convert the next character to uppercase and lowercase, respectively.
--   They may appear within "\U" and "\L" constructs.
-- @param text String text to unescape.
-- @return unescaped text
local function unescape(text)
  text = text:gsub('%f[\\]\\u(%x%x%x%x)', function(code) return utf8.char(tonumber(code, 16)) end)
    :gsub('\\0', buffer.target_text):gsub('\\(%d)', buffer.tag)
  return re_patt:match(text) or text
end

-- Replaces found (selected) text.
events.connect(events.REPLACE, function(text)
  if buffer.selection_empty then return end
  buffer:target_from_selection()
  buffer:replace_target(not M.regex and text or unescape(text))
  buffer:set_sel(buffer.target_start, buffer.target_end)
end)

local INDIC_REPLACE = _SCINTILLA.next_indic_number()
-- Replaces all found text in the current buffer (ignores "Find in Files").
-- If any text is selected (other than text just found), only found text in that selection
-- is replaced.
events.connect(events.REPLACE_ALL, function(ftext, rtext)
  if ftext == '' then return end
  repl_text = rtext -- save for ui.find.focus()
  local count = 0
  local replace_in_sel = not buffer.selection_empty and
    (ftext ~= find_text or buffer:get_sel_text() ~= found_text)
  if replace_in_sel then buffer.indicator_current = INDIC_REPLACE end

  for i = 1, buffer.selections do
    local s, e = buffer.selection_n_start[i], buffer.selection_n_end[i]
    if replace_in_sel then buffer:indicator_fill_range(e, 1) end
    local EOF = replace_in_sel and e == buffer.length + 1 -- no indicator at EOF

    -- Perform the search and replace.
    buffer:begin_undo_action()
    buffer.search_flags = get_flags()
    buffer:set_target_range(not replace_in_sel and 1 or s, buffer.length + 1)
    while buffer:search_in_target(ftext) ~= -1 and
      (not replace_in_sel or buffer.target_end <= buffer:indicator_end(INDIC_REPLACE, s) or EOF) do
      local offset = buffer.target_start ~= buffer.target_end and 0 or 1 -- for preventing loops
      buffer:replace_target(not M.regex and rtext or unescape(rtext))
      count = count + 1
      buffer:set_target_range(buffer.target_end + offset, buffer.length + 1)
    end
    buffer:end_undo_action()

    -- Restore any original selection.
    if replace_in_sel then
      e = buffer:indicator_end(INDIC_REPLACE, s)
      buffer.selection_n_start[i], buffer.selection_n_end[i] = s, e > 1 and e or buffer.length + 1
      if e > 1 then buffer:indicator_clear_range(e, 1) end
    end
  end

  ui.statusbar_text = string.format('%d %s', count, _L['replacement(s) made'])
end)

---
-- Jumps to the source of the find in files search result on line number *line_num* in the buffer
-- titled "Files Found" or, if *line_num* is `nil`, jumps to the next or previous search result,
-- depending on boolean *next*.
-- @param line_num Optional line number in the files found buffer that contains the search
--   result to go to. This parameter may be omitted completely.
-- @param next Optional flag indicating whether to go to the next search result or the previous
--   one. Only applicable when *line_num* is `nil`.
-- @name goto_file_found
function M.goto_file_found(line_num, next)
  if type(line_num) == 'boolean' then line_num, next = nil, line_num end
  local ff_view, ff_buf = nil, nil
  for i = 1, #_VIEWS do
    if is_ff_buf(_VIEWS[i].buffer) then
      ff_view = _VIEWS[i]
      break
    end
  end
  for i = 1, #_BUFFERS do
    if is_ff_buf(_BUFFERS[i]) then
      ff_buf = _BUFFERS[i]
      break
    end
  end
  if not ff_view and not ff_buf then return end
  if ff_view then
    ui.goto_view(ff_view)
  else
    view:goto_buffer(ff_buf)
  end

  -- If no line number was given, find the next search result, wrapping as necessary.
  if not assert_type(line_num, 'number/nil', 1) and next ~= nil then
    buffer[next and 'line_end' or 'home'](buffer)
    buffer:search_anchor()
    local f = next and buffer.search_next or buffer.search_prev
    local pos = f(buffer, buffer.FIND_REGEXP, '^.+:\\d+:.+$')
    if pos == -1 then
      buffer:goto_line(next and 1 or buffer.line_count)
      buffer:search_anchor()
      pos = f(buffer, buffer.FIND_REGEXP, '^.+:\\d+:.+$')
    end
    if pos == -1 then return end
    line_num = buffer:line_from_position(pos)
  end
  buffer:goto_line(line_num)

  -- Goto the source of the search result.
  local line = buffer:get_cur_line()
  local utf8_filename, pos
  utf8_filename, line_num, pos = line:match('^(.+):(%d+):()')
  if not utf8_filename then return end
  line_num = tonumber(line_num)
  textadept.editing.select_line()
  pos = buffer.selection_start + pos - 1 -- absolute pos of result text on line
  local s = buffer:indicator_end(M.INDIC_FIND, buffer.selection_start)
  local e = buffer:indicator_end(M.INDIC_FIND, s)
  if buffer:line_from_position(s) == buffer:line_from_position(pos) then
    s, e = s - pos, e - pos -- relative to line start
  else
    s, e = 0, 0 -- binary file notice, or highlighting was somehow removed
  end
  ui.goto_file(utf8_filename:iconv(_CHARSET, 'UTF-8'), true, preferred_view)
  textadept.editing.goto_line(line_num)
  if buffer:line_from_position(buffer.current_pos + s) == line_num then
    buffer:set_sel(buffer.current_pos + e, buffer.current_pos + s)
  end
end
events.connect(events.KEYPRESS, function(code)
  if keys.KEYSYMS[code] ~= '\n' or not is_ff_buf(buffer) then return end
  M.goto_file_found(buffer:line_from_position(buffer.current_pos))
  return true
end)
events.connect(events.DOUBLE_CLICK,
  function(_, line) if is_ff_buf(buffer) then M.goto_file_found(line) end end)

--[[ The functions below are Lua C functions.

---
-- Mimics pressing the "Find Next" button.
-- @class function
-- @name find_next
local find_next

---
-- Mimics pressing the "Find Prev" button.
-- @class function
-- @name find_prev
local find_prev

---
-- Mimics pressing the "Replace" button.
-- @class function
-- @name replace
local replace

---
-- Mimics pressing the "Replace All" button.
-- @class function
-- @name replace_all
local replace_all
]]