-- lua/nuwiki/keymaps.lua — buffer-local key bindings for `.wiki` buffers.
--
-- Defaults mirror upstream vimwiki's ftplugin layout (see
-- github.com/vimwiki/vimwiki ftplugin/vimwiki.vim), grouped so users
-- can flip subgroups off independently via the `mappings` config:
--
--   mappings = {
--     enabled       = true,
--     links         = true,  -- <CR>, <S-CR>, <Tab>, <BS>, +, …
--     lists         = true,  -- <C-Space>, gln/glp, glx, gl/gL, …
--     headers       = true,  -- =, -, ]], [[, ]=, [=, ]u, [u
--     table_editing = true,  -- gqq, gq1, gww, gw1, <A-Left>, <A-Right>
--     html_export   = true,  -- <Leader>wh, <Leader>whh
--     diary         = true,  -- <C-Down>, <C-Up>, <Leader>w<Leader>*
--     text_objects  = true,  -- ah, ih, al, il
--     wiki_prefix   = true,  -- <Leader>ww, <Leader>ws, <Leader>wi, …
--   }

local M = {}

local function map(mode, lhs, rhs, opts, bufnr)
  opts = vim.tbl_extend('force', { buffer = bufnr or 0, silent = true }, opts or {})
  vim.keymap.set(mode, lhs, rhs, opts)
end

-- ===== Header navigation (pure Lua) =====
--
-- Pure regex jumps, no LSP round-trip. The patterns mirror what
-- vimwiki's `vimwiki#base#goto_*_header` family does, just simpler:
-- match `^\s*=` runs as heading lines.

local function heading_level(line)
  local lead = line and line:match('^%s*(=+)%s')
  if not lead then return 0 end
  local trail = line:match('%s(=+)%s*$')
  if not trail or #trail ~= #lead then return 0 end
  return #lead
end

local function jump_heading(direction, predicate)
  local total = vim.api.nvim_buf_line_count(0)
  local lnum = vim.fn.line('.')
  local step = direction > 0 and 1 or -1
  local i = lnum + step
  while i >= 1 and i <= total do
    local lvl = heading_level(vim.fn.getline(i))
    if lvl > 0 and predicate(lvl, i) then
      vim.api.nvim_win_set_cursor(0, { i, 0 })
      return
    end
    i = i + step
  end
end

local function current_heading_level()
  local total = vim.api.nvim_buf_line_count(0)
  local lnum = vim.fn.line('.')
  for i = lnum, 1, -1 do
    local lvl = heading_level(vim.fn.getline(i))
    if lvl > 0 then return lvl, i end
  end
  return 0, nil
end

local nav = {}
function nav.next_header() jump_heading(1, function() return true end) end
function nav.prev_header() jump_heading(-1, function() return true end) end
function nav.next_sibling_header()
  local lvl = current_heading_level()
  jump_heading(1, function(l) return l <= lvl end)
end
function nav.prev_sibling_header()
  local lvl = current_heading_level()
  jump_heading(-1, function(l) return l <= lvl end)
end
function nav.parent_header()
  local lvl = current_heading_level()
  if lvl <= 1 then return end
  jump_heading(-1, function(l) return l < lvl end)
end

-- ===== Link navigation (pure Lua) =====
--
-- `<Tab>` / `<S-Tab>` jump to the next/prev `[[…]]` on or after the
-- cursor line. The server-side `goto_definition` handles the actual
-- follow; this is just movement.

local function jump_to_pattern(pattern, direction)
  -- Vim's `searchpos` handles forward/backward + wrap.
  local flags = direction > 0 and 'W' or 'bW'
  local pos = vim.fn.searchpos(pattern, flags)
  if pos[1] > 0 then
    vim.api.nvim_win_set_cursor(0, { pos[1], pos[2] - 1 })
  end
end
local link = {}
function link.next() jump_to_pattern([[\[\[]], 1) end
function link.prev() jump_to_pattern([[\[\[]], -1) end

-- ===== List "o"/"O" continuation =====
--
-- Vimwiki's o/O preserves the list bullet on the new line. We
-- approximate: when the current line starts with a list marker, insert
-- the marker on the new line; otherwise fall back to plain o/O.

local function open_below_with_bullet()
  local line = vim.fn.getline('.')
  local indent, marker = line:match('^(%s*)([%-%*#])%s')
  if not marker then
    vim.api.nvim_feedkeys('o', 'n', false)
    return
  end
  local prefix = indent .. marker .. ' '
  -- Also preserve checkbox if present
  local checkbox = line:match('^%s*[%-%*#]%s+(%[[%sxXoO%.%-]%])')
  if checkbox then
    prefix = prefix .. '[ ] '
  end
  vim.api.nvim_feedkeys('o' .. prefix, 'n', false)
end
local function open_above_with_bullet()
  local line = vim.fn.getline('.')
  local indent, marker = line:match('^(%s*)([%-%*#])%s')
  if not marker then
    vim.api.nvim_feedkeys('O', 'n', false)
    return
  end
  local prefix = indent .. marker .. ' '
  vim.api.nvim_feedkeys('O' .. prefix, 'n', false)
end

-- ===== Public attach =====

function M.attach(bufnr, mappings)
  local cmd = require('nuwiki.commands')
  if not mappings or mappings.enabled == false then
    return
  end

  -- Default a missing subgroup to true so users only opt *out*.
  local function on(group)
    if mappings[group] == nil then return true end
    return mappings[group] ~= false
  end

  -- Configurable wiki command prefix (vimwiki's `g:vimwiki_map_prefix`).
  -- Every `<prefix>…` mapping below is built from this so users can relocate
  -- the whole family by setting `map_prefix` in setup().
  local p = require('nuwiki.config').options.map_prefix or '<Leader>w'

  -- ===== Wiki prefix (`<prefix>*`, default `<Leader>w*`) =====
  if on('wiki_prefix') then
    map('n', p .. 'w', function() cmd.wiki_index(0) end,     { desc = 'nuwiki: open wiki index' }, bufnr)
    map('n', p .. 't', function() cmd.wiki_tab_index(0) end, { desc = 'nuwiki: open wiki index (tab)' }, bufnr)
    map('n', p .. 's', cmd.wiki_ui_select, { desc = 'nuwiki: pick wiki' }, bufnr)
    map('n', p .. 'i', cmd.diary_index,    { desc = 'nuwiki: open diary index' }, bufnr)
    map('n', p .. '<Leader>w', cmd.diary_today,     { desc = 'nuwiki: today' }, bufnr)
    map('n', p .. '<Leader>y', cmd.diary_yesterday, { desc = 'nuwiki: yesterday' }, bufnr)
    map('n', p .. '<Leader>t', cmd.diary_today_tab, { desc = 'nuwiki: today in a new tab' }, bufnr)
    map('n', p .. '<Leader>m', cmd.diary_tomorrow,  { desc = 'nuwiki: tomorrow (vimwiki <prefix><Leader>m)' }, bufnr)
    map('n', p .. '<Leader>i', cmd.diary_generate_index, { desc = 'nuwiki: rebuild diary index' }, bufnr)
  end

  -- ===== Links =====
  if on('links') then
    map('n', '<CR>',    cmd.follow_link_or_create,
        { desc = 'nuwiki: follow link (or wrap word + follow)' }, bufnr)
    map('n', '<S-CR>',  function() vim.cmd('split');  cmd.follow_link_or_create() end,
        { desc = 'nuwiki: follow link in split' }, bufnr)
    map('n', '<C-CR>',  function() vim.cmd('vsplit'); cmd.follow_link_or_create() end,
        { desc = 'nuwiki: follow link in vsplit' }, bufnr)
    map('n', '<C-S-CR>', cmd.follow_link_drop,
        { desc = 'nuwiki: follow link in tab (reuse existing)' }, bufnr)
    map('n', '<D-CR>',  cmd.follow_link_drop,
        { desc = 'nuwiki: follow link in tab (macOS Cmd alias of <C-S-CR>)' }, bufnr)
    map('n', '<M-CR>',  cmd.badd_link,
        { desc = 'nuwiki: add link target to buffer list' }, bufnr)
    map('n', '<BS>',    '<C-o>', { desc = 'nuwiki: go back', remap = true }, bufnr)
    map('n', '<Tab>',   link.next, { desc = 'nuwiki: next wikilink' }, bufnr)
    map('n', '<S-Tab>', link.prev, { desc = 'nuwiki: prev wikilink' }, bufnr)
    map('n', '+',       cmd.normalize_link, { desc = 'nuwiki: wrap word as wikilink' }, bufnr)
    map('x', '+',       function() cmd.normalize_link(true) end,
        { desc = 'nuwiki: wrap selection as wikilink' }, bufnr)
    -- Upstream binds visual <CR> to the same normalize-link as visual `+`.
    map('x', '<CR>',    function() cmd.normalize_link(true) end,
        { desc = 'nuwiki: wrap selection as wikilink' }, bufnr)
    map('n', p .. 'n', cmd.wiki_goto_page, { desc = 'nuwiki: goto page' }, bufnr)
    map('n', p .. 'd', cmd.delete_file,    { desc = 'nuwiki: delete page' }, bufnr)
    map('n', p .. 'r', cmd.rename_file,    { desc = 'nuwiki: rename page' }, bufnr)
    map('n', p .. 'c', function() cmd.colorize() end,
        { desc = 'nuwiki: wrap word in colour span' }, bufnr)
    map('x', p .. 'c', function() cmd.colorize(nil, true) end,
        { desc = 'nuwiki: wrap selection in colour span' }, bufnr)
  end

  -- ===== Diary nav =====
  if on('diary') then
    map('n', '<C-Down>', cmd.diary_next, { desc = 'nuwiki: next diary entry' }, bufnr)
    map('n', '<C-Up>',   cmd.diary_prev, { desc = 'nuwiki: prev diary entry' }, bufnr)
  end

  -- ===== Lists =====
  if on('lists') then
    -- Three aliases for the same intent. Terminals disagree about
    -- what byte(s) Ctrl+Space produces:
    --   * GUI Neovim / kitty-protocol terminals → `<C-Space>`
    --   * xterm, most legacy terminals → NUL byte → `<C-@>`
    --   * Some Neovim builds spell that same byte `<Nul>` in keymaps
    -- Map all three so the user gets the binding regardless.
    map('n', '<C-Space>', cmd.toggle_list_item, { desc = 'nuwiki: toggle checkbox' }, bufnr)
    map('x', '<C-Space>', cmd.toggle_list_item, { desc = 'nuwiki: toggle checkbox' }, bufnr)
    map('n', '<C-@>',     cmd.toggle_list_item, { desc = 'nuwiki: toggle checkbox' }, bufnr)
    map('x', '<C-@>',     cmd.toggle_list_item, { desc = 'nuwiki: toggle checkbox' }, bufnr)
    map('n', '<Nul>',     cmd.toggle_list_item, { desc = 'nuwiki: toggle checkbox' }, bufnr)
    map('x', '<Nul>',     cmd.toggle_list_item, { desc = 'nuwiki: toggle checkbox' }, bufnr)
    map('n', 'gnt',       cmd.next_task,        { desc = 'nuwiki: next unfinished task' }, bufnr)
    map('n', 'gln',       cmd.cycle_list_item,  { desc = 'nuwiki: increment checkbox' }, bufnr)
    map('x', 'gln',       cmd.cycle_list_item,  { desc = 'nuwiki: increment checkbox' }, bufnr)
    map('n', 'glp',       cmd.cycle_list_item_back, { desc = 'nuwiki: decrement checkbox' }, bufnr)
    map('x', 'glp',       cmd.cycle_list_item_back, { desc = 'nuwiki: decrement checkbox' }, bufnr)
    map('n', 'glx',       cmd.reject_list_item, { desc = 'nuwiki: reject checkbox' }, bufnr)
    map('x', 'glx',       cmd.reject_list_item, { desc = 'nuwiki: reject checkbox' }, bufnr)
    map('n', 'glh', function() cmd.list_change_level(-1, false) end,
        { desc = 'nuwiki: list dedent' }, bufnr)
    map('n', 'gll', function() cmd.list_change_level(1, false) end,
        { desc = 'nuwiki: list indent' }, bufnr)
    map('n', 'gLh', function() cmd.list_change_level(-1, true) end,
        { desc = 'nuwiki: list dedent subtree' }, bufnr)
    map('n', 'gLl', function() cmd.list_change_level(1, true) end,
        { desc = 'nuwiki: list indent subtree' }, bufnr)
    -- Upstream binds case-variant aliases gLH/gLL/gLR == gLh/gLl/gLr.
    map('n', 'gLH', function() cmd.list_change_level(-1, true) end,
        { desc = 'nuwiki: list dedent subtree' }, bufnr)
    map('n', 'gLL', function() cmd.list_change_level(1, true) end,
        { desc = 'nuwiki: list indent subtree' }, bufnr)
    map('n', 'glr', cmd.list_renumber,
        { desc = 'nuwiki: renumber list' }, bufnr)
    map('n', 'gLr', cmd.list_renumber_all,
        { desc = 'nuwiki: renumber all lists' }, bufnr)
    map('n', 'gLR', cmd.list_renumber_all,
        { desc = 'nuwiki: renumber all lists' }, bufnr)
    -- gl<sym>/gL<sym>: set the current item's / whole list's marker (upstream
    -- VimwikiChangeSymbolTo / ChangeSymbolInListTo). 1) is command-only.
    for _, pair in ipairs({
      { '-', '-' }, { '*', '*' }, { '#', '#' }, { '1', '1.' },
      { 'i', 'i)' }, { 'I', 'I)' }, { 'a', 'a)' }, { 'A', 'A)' },
    }) do
      local key, sym = pair[1], pair[2]
      map('n', 'gl' .. key, function() cmd.list_change_symbol(sym, false) end,
          { desc = 'nuwiki: set item marker to ' .. sym }, bufnr)
      map('n', 'gL' .. key, function() cmd.list_change_symbol(sym, true) end,
          { desc = 'nuwiki: set list markers to ' .. sym }, bufnr)
    end
    -- Bare gl/gL: remove the checkbox marker, keep the item text (upstream
    -- VimwikiRemoveSingleCB / RemoveCBInList). They share the `gl…` prefix
    -- with the maps above, so they fire after `timeoutlen` — exactly as
    -- upstream. Remove-done is command-only (`:NuwikiRemoveDone[!]`).
    map('n', 'gl', cmd.list_remove_checkbox,
        { desc = 'nuwiki: remove checkbox (current item)' }, bufnr)
    map('n', 'gL', cmd.list_remove_checkbox_in_list,
        { desc = 'nuwiki: remove checkboxes (whole list)' }, bufnr)
    map('n', 'o',         open_below_with_bullet, { desc = 'nuwiki: open below + bullet' }, bufnr)
    map('n', 'O',         open_above_with_bullet, { desc = 'nuwiki: open above + bullet' }, bufnr)

    -- Insert-mode bindings (matches upstream vimwiki). The list helpers
    -- mutate the buffer via the LSP / `nvim_buf_set_lines`, both of
    -- which work cleanly from insert mode, so no `<C-o>` dance needed.
    map('i', '<C-D>', function() cmd.list_change_level(-1, false) end,
        { desc = 'nuwiki: list dedent (insert)' }, bufnr)
    map('i', '<C-T>', function() cmd.list_change_level(1, false) end,
        { desc = 'nuwiki: list indent (insert)' }, bufnr)
    map('i', '<C-L><C-J>', function() cmd.list_cycle_symbol(1) end,
        { desc = 'nuwiki: cycle list symbol (insert)' }, bufnr)
    map('i', '<C-L><C-K>', function() cmd.list_cycle_symbol(-1) end,
        { desc = 'nuwiki: cycle list symbol backward (insert)' }, bufnr)
    map('i', '<C-L><C-M>', cmd.list_toggle_or_add_checkbox,
        { desc = 'nuwiki: toggle/add checkbox (insert)' }, bufnr)

    -- Smart <CR>: continue list / table rows. `<expr>` so the function
    -- result is the keystrokes fed — keeps undo coherent.
    map('i', '<CR>', cmd.smart_return,
        { desc = 'nuwiki: smart return (insert)', expr = true }, bufnr)
    -- Smart <S-CR>: multiline list item (continuation with no new marker).
    map('i', '<S-CR>', cmd.smart_shift_return,
        { desc = 'nuwiki: multiline list item (insert)', expr = true }, bufnr)
  end

  -- ===== Insert-mode table navigation (Cluster 6) =====
  -- Gated under `table_editing` since it's the same surface.
  if on('table_editing') then
    map('i', '<Tab>', cmd.smart_tab,
        { desc = 'nuwiki: next table cell (insert)', expr = true }, bufnr)
    map('i', '<S-Tab>', cmd.smart_shift_tab,
        { desc = 'nuwiki: prev table cell (insert)', expr = true }, bufnr)
  end

  -- ===== Header levels + nav =====
  if on('headers') then
    -- vimwiki defaults — buffer-local so they don't clash globally.
    map('n', '=',  cmd.heading_add_level,    { desc = 'nuwiki: heading deeper' }, bufnr)
    map('n', '-',  cmd.heading_remove_level, { desc = 'nuwiki: heading shallower' }, bufnr)
    map('n', ']]', nav.next_header,          { desc = 'nuwiki: next header' }, bufnr)
    map('n', '[[', nav.prev_header,          { desc = 'nuwiki: prev header' }, bufnr)
    map('n', ']=', nav.next_sibling_header,  { desc = 'nuwiki: next sibling header' }, bufnr)
    map('n', '[=', nav.prev_sibling_header,  { desc = 'nuwiki: prev sibling header' }, bufnr)
    map('n', ']u', nav.parent_header,        { desc = 'nuwiki: parent header' }, bufnr)
    map('n', '[u', nav.parent_header,        { desc = 'nuwiki: parent header' }, bufnr)
  end

  -- ===== Tables =====
  if on('table_editing') then
    map('n', 'gqq', function() cmd.table_align_or_cmd('gqq') end, { desc = 'nuwiki: align table / gqq' }, bufnr)
    map('n', 'gq1', function() cmd.table_align_or_cmd('gqq') end, { desc = 'nuwiki: align table / gqq' }, bufnr)
    map('n', 'gww', function() cmd.table_align_or_cmd('gww') end, { desc = 'nuwiki: align table / gww' }, bufnr)
    map('n', 'gw1', function() cmd.table_align_or_cmd('gww') end, { desc = 'nuwiki: align table / gww' }, bufnr)
    map('n', '<A-Left>',  cmd.table_move_column_left,  { desc = 'nuwiki: move column left' }, bufnr)
    map('n', '<A-Right>', cmd.table_move_column_right, { desc = 'nuwiki: move column right' }, bufnr)
  end

  -- ===== HTML =====
  if on('html_export') then
    map('n', p .. 'h',  cmd.export_current, { desc = 'nuwiki: export to HTML' }, bufnr)
    map('n', p .. 'hh', cmd.export_browse,  { desc = 'nuwiki: export + browse' }, bufnr)
    map('n', p .. 'ha', cmd.export_all,     { desc = 'nuwiki: export all' }, bufnr)
  end

  -- ===== Mouse (opt-in via `mappings.mouse = true`) =====
  -- Mirrors upstream vimwiki: double-click follows, shift/ctrl-double
  -- open in split/vsplit, middle-click adds the linked file to the
  -- buffer list, right-click + left-click goes back.
  if mappings.mouse then
    map('n', '<2-LeftMouse>',   cmd.follow_link_or_create,
        { desc = 'nuwiki: follow link (mouse)' }, bufnr)
    map('n', '<S-2-LeftMouse>', function() vim.cmd('split');  cmd.follow_link_or_create() end,
        { desc = 'nuwiki: follow link in split (mouse)' }, bufnr)
    map('n', '<C-2-LeftMouse>', function() vim.cmd('vsplit'); cmd.follow_link_or_create() end,
        { desc = 'nuwiki: follow link in vsplit (mouse)' }, bufnr)
    map('n', '<MiddleMouse>',   cmd.badd_link,
        { desc = 'nuwiki: badd link target' }, bufnr)
    map('n', '<RightMouse>',    '<C-o>',
        { desc = 'nuwiki: go back (mouse)', remap = true }, bufnr)
  end
end

return M