local gcm = require 'presser.context_manager'
local steamers = require 'presser.steamers'
local actions = require 'presser.actions'
local utils   = require 'presser.utils'

local a = vim.api

local modules = {}

-- @Description: Find and replace words within the current buffer.
-- @Params:
-- @Returns: nil.
--
-- @Dev: function is responsible to creating all required buffers to allow full user interaction.
--
-- @Future: implementation may allow for greater user customisation similar to what's found with
-- extensions such as Telescope. For now, it should provide a concrete UI for purpose of design.
modules.find_replace = function ()
  -- define the context which these windows will belong to in the context manager.
  local ctx = "find_replace"
  gcm.create( ctx )
  
  local keymap = {
    n = {
      ["<esc>"] = "<cmd>lua require'presser.actions'.close()<CR>",
      ["<A-a>"] = "<cmd>lua require'presser.actions'.execute()<CR>",
    },
    i = {
      ["<down>"] = "<cmd>lua require'presser.actions'.move_next_buffer()<CR>",
      ["<A-a>"] = "<cmd>lua require'presser.actions'.execute()<CR>",
    }
  }

  -- get the centre of the current buffer
  local c_cols = math.floor( a.nvim_win_get_width(0) / 2 )
  local c_lines = math.floor( a.nvim_win_get_height(0) / 2 )

  -- create a title buffer for the steamer
  steamers
    .new( ctx, {
      label = "presser_title",
      steamer = {
        placeholder = "Find & Replace",
        allowed = false,
        window = {
          line = c_lines - 3,
          border = false,
          minwidth = 82,
          padding = { 0, 1, 1, 1 }
        }
      }
    } )

  -- create a new buffer for find pattern
  steamers
    .new ( ctx, {
      label = "find_buf",
      steamer = {
        window = {
          line = c_lines,
          title = "Find",
        },
        keybinds = keymap,
      }
    } )

  -- create a new buffer for replace pattern
  steamers
    .new( ctx, {
      label = "replace_buf",
      steamer = {
        window = {
          line = c_lines + 3,
          title = "Replace",
        },
        keybinds = keymap,
      }
    } )

  local result = actions.buf_put_curser_at( "find_buf" )
  a.nvim_feedkeys('A', 'n', false)
end


modules.hyperlink = function ()
  local check_url = function ( text )
    local text = string.lower( text )

    -- string list of all possible URI schemes which have RFC specification and identified with permanent status
    local patterns = "aaa|aaas|about|acap|acct|afs|cap|cid|coap|coap+tcp|coap+ws|coaps|coaps+tcp|coaps+ws|crid|data" ..
      "|dav|dict|dns|dtn|example|fax|file|ftp|geo|go|gopher|h323|ham|http|https|iax|icap|im|imap|info|ipn|ipp|ipps" ..
      "|iris|iris.beep|iris.lwz|iris.xpc|iris.xpcs|jms|ldap|leaptofrogans|mailserver|mailto|mid|modem|msrp|msrps" ..
      "|mtqp|mupdate|news|nfs|ni|nih|nntp|opaquelocktoken|payto|pkcs11|pop|pres|prospero|reload|rsync|rtmfp|rtsp" ..
      "|rtsps|rtspu|secret-token|service|session|sieve|sip|sips|sms|snews|snmp|soap.beep|soap.beeps|stun|stuns|tag" ..
      "|tel|telnet|tftp|thismessage|tip|tn3270|turn|turns|tv|urn|vemmi|videotex|vnc|wais|ws|wss|xcon|xcon-userid" ..
      "|xmlrpc.beep|xmlrpc.beeps|xmpp|z39.50|z39.50r|z39.50s|"

    -- check if text is a type of URI
    -- @Dev: TODO, consider option of logarithmic matching (patterns already in alphabetical order)
    for proto in string.gmatch( patterns, "([^|]+)" ) do
      -- if so, text can be converted directly to hyperlink (return true)
      if string.find( text, proto ) then
        return true
      end
    end

    return false
  end


  local link_txt = nil
  local row, col = unpack(a.nvim_win_get_cursor(0))
  local h,j,_,l = utils.get_selection()
  local line = a.nvim_get_current_line()
  if vim.api.nvim_get_mode()["mode"] == "n" then
    if (row-1) == h and (col == j or col == l) then
      print("visual mode selection")
      link_txt = string.sub(line, j, l)
    else
      link_txt = string.sub(line, unpack(utils.subslice(line, col)))
    end
  else
    link_txt = vim.fn.expand "<cexpr>"
  end

  link_txt = utils.clean_buf(link_txt)
  if link_txt == "" then
    print("Presser.hyperlink: No text selected to convert.")
    return
  end

  if check_url( link_txt ) then
    print("Identified URI scheme under cursor, generating hyperlink for: " .. link_txt)
    if not ( col == j or col == l ) then
      j, l = unpack(utils.subslice( line .. " ", col ))
    end

    print(j,l)
    actions.suburl( line, row, link_txt, j, l )
    return nil
  end

  print("Cursor is not over an identified URI scheme: " .. link_txt .. ". Constructing UI...")

  -- define the context which these windows will belong to in the context manager.
  local ctx = "hyperlink"
  gcm.create( ctx )

  local keymap = {
    n = {
      ["<esc>"] = "<cmd>lua require'presser.actions'.close()<CR>",
      ["<A-a>"] = "<cmd>lua require'presser.actions'.hyperlink_exec()<CR>",
    },
    i = {
      ["<A-a>"] = "<cmd>lua require'presser.actions'.hyperlink_exec()<CR>",
    }
  }

  -- get the centre of the current buffer
  local c_lines = math.floor( a.nvim_win_get_height(0) / 2 )

  -- create a title buffer for the steamer
  steamers
    .new( ctx, {
      label = "presser_title",
      steamer = {
        placeholder = "Hyperlink",
        allowed = false,
        window = {
          line = c_lines - 2,
          border = false,
          minwidth = 82,
          padding = { 0, 1, 1, 1 }
        }
      }
    } )

  steamers
    .new( ctx, {
      label = "selected_text",
      steamer = {
        placeholder = "Selected text: " .. link_txt,
        allowed = false,
        window = {
          line = c_lines,
          border = false,
          minwidth = 82,
          padding = { 0, 1, 1, 1 }
        }
      }
    } )

  -- create a new buffer for replace pattern
  steamers
    .new( ctx, {
      label = "hyperlink_buf",
      steamer = {
        window = {
          line = c_lines + 3,
          title = "Hyperlink",
        },
        keybinds = keymap,
      }
    } )

  local result = actions.buf_put_curser_at( "hyperlink_buf" )
  a.nvim_feedkeys('A', 'n', false)
end

return modules