local ui = require("fschauen.util.icons").ui

---Create the left hand side for a Telescope keymap.
local lhs = function(keys) return "<leader>f" .. keys end

---Create the description for a Telescope keymap.
local desc = function(text) return ui.Telescope .. " Telescope " .. text end

local builtin_picker = function(name, opts)
  return function(title)
    return function()
      local picker = require("telescope.builtin")[name]
      picker(vim.tbl_extend("force", opts or {}, {
        prompt_title = title,
      }))
    end
  end
end

local pickers = setmetatable({
  all_files = builtin_picker("find_files", {
    hidden = true,
    no_ignore = true,
    no_ignore_parent = true,
  }),
  all_man_pages = builtin_picker("man_pages", {
    sections = { "ALL" },
  }),
  colorscheme = builtin_picker("colorscheme", { enable_preview = true }),
  diagnostics = builtin_picker("diagnostics", { bufnr = 0 }),
  dotfiles = builtin_picker("find_files", { cwd = "~/.dotfiles", hidden = true }),
  selection = function(title)
    return function()
      local text = require("fschauen.util").get_selected_text()
      return require("telescope.builtin").grep_string {
        prompt_title = string.format(title .. ": %s  ", text),
        search = text,
      }
    end
  end,
  here = builtin_picker("current_buffer_fuzzy_find"),
}, {
  -- Fall back to telescope's built-in pickers if a custom one is not defined
  -- above, but make sure to keep the title we defined.
  __index = function(_, key) return builtin_picker(key) end,
})

return {
  "nvim-telescope/telescope.nvim",

  dependencies = {
    "nvim-telescope/telescope-fzf-native.nvim",
    build = "cmake -S. -Bbuild -DCMAKE_BUILD_TYPE=Release "
      .. "&& cmake --build build --config Release "
      .. "&& cmake --install build --prefix build",
  },

  cmd = "Telescope",

  keymap_helper = { lhs = lhs, description = desc },

  keys = {
    -- stylua: ignore start
    { lhs"a",  pickers.autocommands           "  Autocommands"         , desc = desc("[a]utocommands")            },
    { lhs"b",  pickers.buffers                "  Buffers"              , desc = desc("[b]uffers")                 },
    --lhs"B"   used in telescope-file-browser
    { lhs"c",  pickers.colorscheme            "  Colorschemes"         , desc = desc("[c]olorschemes")            },
    { lhs"C",  pickers.commands               "  Commands"             , desc = desc("[C]ommands")                },
    { lhs"d",  pickers.diagnostics            "󰀪  Diagnostics"          , desc = desc("[d]iagnostics")             },
    --lhs"e"
    { lhs"f",  pickers.find_files             "  Files"                , desc = desc("[f]ind files")              },
    { lhs"F",  pickers.all_files              "  ALL files"            , desc = desc("all [F]iles")               },
    { lhs"gr", pickers.live_grep              "  Live grep"            , desc = desc("Live [gr]ep")               },
    { lhs"gf", pickers.git_files              "  Git files"            , desc = desc("[g]it [f]iles")             },
    { lhs"gc", pickers.git_commits            " Commits"             , desc = desc("[g]it [c]ommits")           },
    { lhs"h",  pickers.here                   "  Current buffer"       , desc = desc("[b]uffer [h]ere")           },
    { lhs"H",  pickers.highlights             "󰌶  Highlights"           , desc = desc("[H]ighlights")              },
    --lhs"i"   used in nerdy
    { lhs"j",  pickers.jumplist               "  Jumplist"             , desc = desc("[j]umplist")                },
    { lhs"k",  pickers.keymaps                "  Keymaps"              , desc = desc("[k]eymaps")                 },
    { lhs"K",  pickers.help_tags              "  Help tags"            , desc = desc("[K] help/documentation")    },
    { lhs"l",  pickers.loclist                "  Location list"        , desc = desc("[l]ocation List")           },
    { lhs"m",  pickers.all_man_pages          "  Man pages"            , desc = desc("[m]an pages")               },
    --lhs"n"   used in vim-notify
    { lhs"o",  pickers.vim_options            "  Vim options"          , desc = desc("[o]ptions")                 },
    --lhs"p"
    { lhs"q",  pickers.quickfix               "  Quickfix"             , desc = desc("[q]uickfix")                },
    { lhs"r",  pickers.lsp_references         "  References"           , desc = desc("[r]eferences")              },
    { lhs"R",  pickers.registers              "󱓥  Registers"            , desc = desc("[R]registers")              },
    { lhs"s",  pickers.lsp_document_symbols   "󰫧  Document Symbols "    , desc = desc("LSP document [s]ymbols")    },
    { lhs"S",  pickers.lsp_workspace_symbols  "󱄑  Workspace Symbols "   , desc = desc("LSP workspace [S]ymbols")   },
    --lhs"t"   used in todo_comments
    { lhs"T",  pickers.treesitter             "  Treesitter symbols"   , desc = desc("[T]reesitter Symbols")      },
    --lhs"u"
    --lhs"v"
    { lhs"w",  pickers.selection              "  Grep"                 , desc = desc("[w]word under cursor")      },
    { lhs"w",  pickers.selection              "  Grep",  mode = "v"    , desc = desc("[w]ord(s) selected")        },
    --lhs"x"
    --lhs"y"
    { lhs"z",  pickers.spell_suggest          "󰓆  Spelling suggestions" , desc = desc("[z] spell suggestions")     },
    { lhs".",  pickers.dotfiles               "  Dotfiles"             , desc = desc("[.]dotfiles")               },
    { lhs":",  pickers.command_history        "  Command history"      , desc = desc("[:]command history")        },
    { lhs"/",  pickers.search_history         "  Search history"       , desc = desc("[/]search history")         },
    { lhs"<leader>", pickers.resume           "󰐎  Resume"               , desc = desc("Resume ")                   },
    -- stylua: ignore end
  },

  opts = function()
    local actions = require("telescope.actions")
    local layout = require("telescope.actions.layout")
    local state = require("telescope.actions.state")

    local clear_prompt = function(prompt_bufnr)
      state.get_current_picker(prompt_bufnr):reset_prompt()
    end

    local mappings = {
      ["<c-y>"] = layout.cycle_layout_next,
      ["<c-u>"] = clear_prompt,
      ["<c-i>"] = actions.toggle_selection + actions.move_selection_next,
      ["<c-o>"] = actions.toggle_selection + actions.move_selection_previous,
      ["<c-p>"] = layout.toggle_preview,

      ["<c-j>"] = actions.move_selection_next,
      ["<c-k>"] = actions.move_selection_previous,

      ["<c-f>"] = actions.results_scrolling_down,
      ["<c-b>"] = actions.results_scrolling_up,

      ["<s-down>"] = actions.preview_scrolling_down,
      ["<s-up>"] = actions.preview_scrolling_up,

      ["<c-s>"] = actions.select_horizontal,
      ["<c-x>"] = false,
      ["<c-c>"] = actions.close,

      ["<c-q>"] = actions.smart_send_to_qflist + actions.open_qflist,
      ["<c-l>"] = actions.smart_send_to_loclist + actions.open_loclist,
    }

    return {
      defaults = {
        mappings = { i = mappings, n = mappings },

        prompt_prefix = " " .. ui.Telescope .. "  ",
        selection_caret = ui.Play .. " ",

        multi_icon = ui.Checkbox .. " ",
        scroll_strategy = "limit", -- Don't wrap around in results.

        dynamic_preview_title = true,

        layout_strategy = "flex",
        layout_config = {
          width = 0.9,
          height = 0.9,
          flex = { flip_columns = 180 },
          horizontal = { preview_width = 0.5 },
          vertical = { preview_height = 0.5 },
        },
        cycle_layout_list = {
          "horizontal",
          "vertical",
        },
      },
      pickers = {
        buffers = {
          mappings = {
            n = { x = actions.delete_buffer },
            i = { ["<c-x>"] = actions.delete_buffer },
          },
        },
        colorscheme = { theme = "dropdown" },
        spell_suggest = { theme = "cursor" },
      },
    }
  end,

  config = function(_, opts)
    require("telescope").setup(opts)
    require("telescope").load_extension("fzf")
    vim.api.nvim_create_autocmd("User", {
      desc = "Enable line number in Telescope previewers.",
      group = vim.api.nvim_create_augroup("fschauen.telescope", { clear = true }),
      pattern = "TelescopePreviewerLoaded",
      command = "setlocal number",
    })
  end,
}