--- Personal lua config files for NeoVim.
--  Last Changed: 2019-01-27
--  Author: Federico Igne <git@federicoigne.com>
--  License: This file is placed in the public domain.

local api = vim.api
local cmd = vim.cmd

local statusline = {}

--- Custom mode flags
local mode_flags = {
  ["n"]  = "N",
  ["v"]  = "V",
  ["V"]  = "V·Line",
  [""] = "V·Block",
  ["s"]  = "S",
  ["S"]  = "S·Line",
  [""] = "S·Block",
  ["i"]  = "I",
  ["R"]  = "R",
  ["c"]  = "C",
  ["r"]  = "Prompt",
  ["!"]  = "Shell",
  ["t"]  = "T"
}

--- Custom filetype flags (overrides mode flag)
local filetype_flags = {
  help      = 'Help',
  qf        = 'QFix',
  netrw     = 'Netrw',
  fugitive  = 'Gstatus',
  tagbar    = 'TagBar',
  gitcommit = 'Gcommit'
}

--- Custom name flags (overrides mode flag)
local name_flags = {
  ['[Grammarous]'] = 'Grammar'
}

--- Preview flag (overrides mode flag)
local preview_flag = {
  [true] = 'Preview'
}

--- Get mode flag for current buffer
local function modeflag()
    local label
    local preview = vim.o.previewwindow
    local name = api.nvim_buf_get_name(api.nvim_get_current_buf())
    local filetype = vim.o.filetype
    local mode = vim.api.nvim_get_mode().mode:sub(1, 1)
    return preview_flag[preview] or name_flags[name] or filetype_flags[filetype] or mode_flags[mode]
end

--- Get formatted filename
local function filename()
  local filename = ''
  local bufname = vim.fn.expand('%')
  if bufname:len() == 0 then
    -- New (empty) buffer
    filename = "%1*[No Name]%*"
  elseif bufname:find('^term://.*') then
    -- Terminal buffer
    local _,_,pid,cmd = bufname:find('term://.+//(%d+):(.+)')
    filename = "%1*" .. cmd .. " (" .. pid .. "/" .. vim.o.channel .. ")%*"
  else
    -- Other buffers
    local path = vim.fn.expand('%:h')
    if path ~= '' and path ~= '.' then
      filename = "%1*" .. path .. "/%*"
    end
    filename = filename .. "%2*%t%*"
  end
  return filename
end

-- Get git information
local function gitinfo()
  local git = ''
  if vim.fn.exists('*FugitiveHead') then
    local head = vim.fn.FugitiveHead(8)
    local status = vim.b.gitsigns_status_dict
    if head:len() > 0 then
      git = git .. head .. ' '
    end
    if status and status.added and status.changed and status.removed then
      git = git .. string.format('(+%d ~%d -%d) ', status.added, status.changed, status.removed)
    end
  end
  return git
end

-- Return a flag if a session is being tracked
function statusline.session()
  local session = ''
  if require('dyamon').session.exists() then
    session = ',s'
  end
  if vim.t.this_session then
    session = ',S'
  end
  return session
end

-- Return file encoding flag if different from default (utf8).
function statusline.fileenc()
  local fileenc = vim.bo.fileencoding
  if fileenc ~= 'utf-8' and fileenc ~= '' then
    return ',' .. fileenc
  else
    return ''
  end
end

-- Return (lowercase) filetype flag
function statusline.filetype()
  local filetype = vim.bo.filetype
  if filetype ~= '' then
    return ',' .. filetype
  else
    return ''
  end
end

local function statusline_focused()
  local status = ''
  local accent = "%3*"
  if vim.bo.modified then
    accent = "%4*"
  end
  status = accent .. " " .. modeflag() .. " %*%< "
  status = status .. filename() .. "%="
  status = status .. gitinfo()
  --status = status .. zettelstatus() .. " "
  status = status .. "[%M%R%{v:lua.dyamon.statusline.session()}%{v:lua.dyamon.statusline.fileenc()}%{v:lua.dyamon.statusline.filetype()}]" .. " "
  status = status .. accent .. " %3l/%L %2c/%2{%len(getline('.'))%} [%P]"
  --status = status .. " " .. lsp()
  return status
end

local function statusline_blurred()
  return " %<%f%="
end

function statusline.update()
  local current = vim.g.statusline_winid == api.nvim_get_current_win()
  if current then
      return statusline_focused()
  else
      return statusline_blurred()
  end
end

return statusline