local M = {}

local diagnostic = require 'fschauen.diagnostic'
local window = require 'fschauen.window'
local pickers = require('fschauen.telescope').pickers

local toggle_number = function()
  vim.wo.number = not vim.wo.number
  vim.wo.relativenumber = false
end

local toggle_relativenumber = function()
  vim.wo.relativenumber = not vim.wo.relativenumber
  vim.wo.number = vim.wo.relativenumber or vim.wo.number
end

local toggle_colorcolumn = function()
  if vim.o.colorcolumn == '' then
    vim.o.colorcolumn = '+1'  -- one after 'textwidth'
  else
    vim.o.colorcolumn = ''    -- none
  end
end

local keymap = {
  -- better navigation for wrapped lines
  { 'j', 'gj' },
  { 'k', 'gk' },

  -- maintain cursor position when joining lines
  { 'J', 'mzJ`z' },

  -- retain selection when making changes in visual mode
  {  '<c-a>',  '<c-a>gv', 'v' },
  {  '<c-x>',  '<c-x>gv', 'v' },
  { 'g<c-a>', 'g<c-a>gv', 'v' },
  { 'g<c-x>', 'g<c-x>gv', 'v' },
  {      '>',  '><cr>gv', 'v' },
  {      '<',  '<<cr>gv', 'v' },

  -- place destination of important movements in the center of the screen
  {     'n',     'nzzzv' },
  {     'N',     'Nzzzv' },
  { '<c-d>', '<c-d>zzzv' },
  { '<c-u>', '<c-u>zzzv' },

  -- easier window navigation
  { '<c-j>', '<c-w>j' },
  { '<c-k>', '<c-w>k' },
  { '<c-h>', '<c-w>h' },
  { '<c-l>', '<c-w>l' },

  -- window resizing
  {    '<s-Up>',    window.resize_up(2), desc = 'Resize window upward'    },
  {  '<s-Down>',  window.resize_down(2), desc = 'Resize window downward'  },
  {  '<s-Left>',  window.resize_left(2), desc = 'Resize window leftward'  },
  { '<s-Right>', window.resize_right(2), desc = 'Resize window rightward' },

  -- easy tab navigation
  { '<Right>', '<cmd>tabnext<cr>' },
  {  '<Left>', '<cmd>tabprevious<cr>' },

  -- move lines up and down
  { '<c-a-j>', [[:move .+1<cr>==]] },
  { '<c-a-k>', [[:move .-2<cr>==]] },
  { '<c-a-j>', [[:move '>+1<cr>gv=gv]], 'v' },
  { '<c-a-k>', [[:move '<-2<cr>gv=gv]], 'v' },
  { '<c-a-j>', [[<esc>:move .+1<cr>==gi]], 'i' },
  { '<c-a-k>', [[<esc>:move .-2<cr>==gi]], 'i' },

  -- move to begin/end of line in insert mode
  { '<c-a>', '<c-o>^', 'i' },
  { '<c-e>', '<c-o>$', 'i' },

  -- move to begin of line in command mode (<c-e> moves to end by default)
  { '<c-a>', '<c-b>', 'c' },

  -- more convenient way of entering normal mode from terminal mode
  { [[<c-\><c-\>]], [[<c-\><c-n>]], 't' },

  -- recall older/recent command-line from history
  { '<c-j>', '<down>', 'c' },
  { '<c-k>', '<up>',   'c' },

  -- quickly change background
  { '<leader>bg', [[<cmd>let &background = &background ==? 'light' ? 'dark' : 'light'<cr>]] },

  -- navigate diagnostics
  { '<leader>dj', diagnostic.goto_next },
  { '<leader>dk', diagnostic.goto_prev },
  { '<leader>dd', diagnostic.toggle },
  { '<leader>do', diagnostic.open_float },
  { '<leader>dh', diagnostic.hide },

  telescope = {
    { '<leader>fa',  pickers.autocommands           ('  Autocommands'         ), desc = ' [a]utocommands'            },
    { '<leader>fb',  pickers.buffers                ('  Buffers'              ), desc = ' [b]uffers'                 },
    { '<leader>fB', '<cmd>Telescope file_browser<cr>'                           , desc = ' file [B]rowser'            },
    { '<leader>fc',  pickers.colorscheme            ('  Colorschemes'         ), desc = ' [c]olorschemes'            },
    { '<leader>fdd', pickers.diagnostics            ('󰀪  Document Diagnostics' ), desc = ' [d]iagnostics [d]ocument'  },
    { '<leader>fdw', pickers.diagnostics            ('󰀪  Workspace Diagnostics'), desc = ' [d]iagnostics [w]orkspace' },
    --'<leader>fe'
    { '<leader>ff',  pickers.find_files             ('  Files'                ), desc = ' [f]ind files'              },
    { '<leader>fF',  pickers.all_files              ('  ALL files'            ), desc = ' all [F]iles'               },
    { '<leader>fgr', pickers.live_grep              ('  Live grep'            ), desc = ' Live [gr]ep'               },
    { '<leader>fgf', pickers.git_files              ('  Git files'            ), desc = ' [g]it [f]iles'             },
    { '<leader>fgc', pickers.git_commits            (' Commits'             ), desc = ' [g]it [c]ommits'           },
    { '<leader>fh',  pickers.here                   ('  Current buffer'       ), desc = ' [b]uffer [h]ere'           },
    { '<leader>fH',  pickers.highlights             ('󰌶  Highlights'           ), desc = ' [H]ighlights'              },
    --'<leader>fi'
    { '<leader>fj',  pickers.jumplist               ('  Jumplist'             ), desc = ' [j]umplist'                },
    { '<leader>fk',  pickers.keymaps                ('  Keymaps'              ), desc = ' [k]eymaps'                 },
    { '<leader>fK',  pickers.help_tags              ('  Help tags'            ), desc = ' [K] help/documentation'    },
    { '<leader>fl',  pickers.loclist                ('  Location list'        ), desc = ' [l]ocation List'           },
    { '<leader>fm',  pickers.man_pages              ('  Man pages'            ), desc = ' [m]an pages'               },
    --'<leader>fn'
    { '<leader>fo',  pickers.vim_options            ('  Vim options'          ), desc = ' vim [o]ptions'             },
    --'<leader>fp'
    { '<leader>fq',  pickers.quickfix               ('  Quickfix'             ), desc = ' [q]uickfix'                },
    { '<leader>fr',  pickers.lsp_references         ('  References'           ), desc = ' [r]eferences'              },
    { '<leader>fR',  pickers.registers              ('󱓥  Registers'            ), desc = ' [R]registers'              },
    { '<leader>fs',  pickers.lsp_document_symbols   ('󰫧  Document Symbols '    ), desc = ' lsp document [s]ymbols'    },
    { '<leader>fS',  pickers.lsp_workspace_symbols  ('󱄑  Workspace Symbols '   ), desc = ' lsp workspace [S]ymbols'   },
    --'<leader>ft'   used in todo_comments below
    { '<leader>fT',  pickers.treesitter             ('  Treesitter symbols'   ), desc = ' [T]reesitter Symbols'      },
    --'<leader>fu'
    --'<leader>fv'
    { '<leader>fw',  pickers.selection              (--[[dynamic]])             , desc = ' [w]word under cursor'      },
    { '<leader>fw',  pickers.selection              (--[[dynamic]]),        'v' , desc = ' visual [s]election'        },
    --'<leader>fx'
    --'<leader>fy'
    { '<leader>fz',  pickers.spell_suggest          ('󰓆  Spelling suggestions') , desc = ' [z] spell suggestions'     },
    { '<leader>f.',  pickers.dotfiles               ('  Dotfiles'            ) , desc = ' [.]dotfiles'               },
    { '<leader>f:',  pickers.command_history        ('  Command history'     ) , desc = ' [:]command history'        },
    { '<leader>f?',  pickers.commands               ('  Commands'            ) , desc = ' commands [?]'              },
    { '<leader>f/',  pickers.search_history         ('  Search history'      ) , desc = ' [/]search history'         },
    { '<leader>f<leader>', pickers.resume           ('󰐎  Resume'              ) , desc = ' Resume '                   },
  },

  todo_comments = {
    { '<leader>ft', '<cmd>TodoTelescope<cr>' },
  },

  fugitive = {
    { '<leader>gg', ':Git ' },
    { '<leader>gs', '<cmd>tab Git<cr>' },
    { '<leader>gb', '<cmd>Git blame<cr>' }
  },

  neogit = {
    { '<leader>gn', '<cmd>Neogit<cr>' },
  },

  -- disable highlight until next search
  { '<leader>h', '<cmd>nohlsearch<cr><esc>' },

  -- navigate items in quickfix and location lists
  {      '<leader>j', '<cmd>cnext<cr>zz' },
  {      '<leader>k', '<cmd>cprevious<cr>zz' },
  { '<localleader>j', '<cmd>lnext<cr>zz' },
  { '<localleader>k', '<cmd>lprevious<cr>zz' },

  -- toggle quickfix and loclist
  {      '<leader>ll', window.toggle_quickfix,  desc = 'Toggle quickfix'  },
  { '<localleader>ll', window.toggle_loclist,   desc = 'Toggle loclist'   },

  trouble = {
    { '<leader>lt', '<cmd>TroubleToggle<cr>' },
    { '<leader>lw', '<cmd>TroubleToggle workspace_diagnostics<cr>' },
    { '<leader>ld', '<cmd>TroubleToggle document_diagnostics<cr>' },
  },

  -- quickly open lazy.nvim plugin manager
  { '<leader>L', '<cmd>Lazy<cr>' },

  nvim_tree = {
    { '<leader>nn', '<cmd>NvimTreeOpen<cr>' },
    { '<leader>nf', '<cmd>NvimTreeFindFile<cr>' },
    { '<leader>nc', '<cmd>NvimTreeClose<cr>' },
  },

  -- toggle options
  { '<leader>sn', toggle_number },
  { '<leader>sr', toggle_relativenumber },
  { '<leader>sl', '<cmd>set list!  | set list?<CR>' },
  { '<leader>sw', '<cmd>set wrap!  | set wrap?<CR>' },
  { '<leader>ss', '<cmd>set spell! | set spell?<CR>' },

  virt_column = {
    { '<leader>sc', toggle_colorcolumn, desc = 'Toggle virtual colunn' },
  },

  indent_blankline = {
    { '<leader>si', '<cmd>IndentBlanklineToggle<cr>' },
  },

  treesitter = {
    { '<leader>tp', '<cmd>TSPlaygroundToggle<cr>' },
    { '<leader>th', '<cmd>TSHighlightCapturesUnderCursor<cr>' },
    { '<leader>tn', '<cmd>TSNodeUnderCursor<cr>' },
  },

  undotree = {
    { '<leader>u', '<cmd>UndotreeToggle<cr>' },
  },

  whitespace ={
    { '<leader>ww', '<cmd>ToggleWhitespace<cr>' },
    { '<leader>wj', '<cmd>NextTrailingWhitespace<cr>' },
    { '<leader>wk', '<cmd>PrevTrailingWhitespace<cr>' },
    { '<leader>wd', '<cmd>StripWhitespace<cr>' },
  },
}

M.setup = function()
  local keymap_set = vim.keymap.set
  local set = function(opts)
    local lhs, rhs, mode = opts[1], opts[2], opts[3] or 'n'
    opts[1], opts[2], opts[3], opts.mode = nil, nil, nil, nil
    opts.silent = opts.silent ~= false
    keymap_set(mode, lhs, rhs, opts)
  end

  for _, mapping in ipairs(keymap) do
    set(mapping)
  end
end

setmetatable(M, {
  __index = function (_, k)
   return keymap[k]
  end
})

return M