local M = {}
local wk = require('which-key')
local api, notify = vim.api, vim.notify
local opts = {noremap = true, silent = true}

-------------------------------
-- Globally defined mappings --
-------------------------------
local normal_mappings = {
    -- Easier start and end of line
    H = {'^', 'Start of the line'},
    L = {'$', 'End of the line'},
    -- Close a window
    ['<C-q>'] = {'<C-w>q', 'Quit current window'},
    -- Close current buffer
    ['<A-q>'] = {':bdelete<CR>', 'Close current buffer'},
    -- Copy the whole buffer
    ['<A-a>'] = {':%y+<CR>', 'Copy whole buffer'},
    -- Remove trailing whitespace
    ['<A-w>'] = {':%s/\\s\\+$//e<CR>', 'Remove trailing'},
    -- Resize buffer
    ['<A-j>'] = {':resize -2<CR>', 'Resize vertical -2'},
    ['<A-k>'] = {':resize +2<CR>', 'Resize vertical +2'},
    ['<A-h>'] = {':vertical resize -2<CR>', 'Resize horizontal -2'},
    ['<A-l>'] = {':vertical resize +2<CR>', 'Resize horizontal +2'},
    -- Switch between tabs and spaces
    ['<A-t>'] = {
        function()
            if vim.opt.expandtab:get() then
                vim.opt.expandtab = false
                vim.opt.smarttab = false
                vim.opt.softtabstop = 0 -- reset to default
                notify('Indent with Tabs.', vim.log.levels.INFO)
            else
                vim.opt.expandtab = true
                vim.opt.smarttab = true
                vim.opt.softtabstop = -1 -- fallback to shiftwidth
                notify('Indent with Spaces.', vim.log.levels.INFO)
            end
        end,
        'Switch indent style'
    },
    -- Naming common keys
    ['['] = {
        name = 'Block motions (previous)',
        g = 'Previous git hunk'
    },
    [']'] = {
        name = 'Block motions (next)',
        g = 'Next git hunk'
    },
    g = {
        name = 'Goto motions',
        t = {':TodoTrouble<CR>', 'Todo list'}
    },
    z = {name = 'Misc utils'},
    -- Move between tabs
    ['<TAB>'] = {':BufferLineCycleNext<CR>', 'Next buffer'},
    ['<S-TAB>'] = {':BufferLineCyclePrev<CR>', 'Previous buffer'},
    -- ToggleTerm
    ['<C-\\>'] = {':ToggleTerm<CR>', 'Toggle terminal'},
    ['<A-\\>'] = {':ToggleTerm direction=float<CR>', 'Toggle float terminal'},
    -- hop.nvim
    S = {':HopWord<CR>', 'Hop to word'},
    ['<C-s>'] = {':HopChar1<CR>', 'Hop to character'},
    ['<A-s>'] = {':HopPattern<CR>', 'Hop to pattern'}
}

local normal_leader_mappings = {
    d = {
        name = 'DAP',
        b = 'Toggle breakpoint',
        B = 'Set breakpoint with condition',
        c = 'Run to cursor',
        d = 'Disconnect adapter',
        e = 'Hover under cursor (UI)',
        f = 'Open float window (UI)',
        i = 'Step into function/method',
        l = 'List breakpoints',
        n = 'Resume the execution',
        o = 'Step out of function/method',
        r = 'Inspect in REPL',
        t = 'Toggle UI',
        v = 'Run again 1 step',
        z = 'Re-run the last adapter'
    },
    e = {
        name = 'Editor',
        a = {':EasyAlign<CR>', 'Align elements'},
        g = 'Generate annotations',
        h = {':TSHighlightCapturesUnderCursor<CR>', 'Syntax under cursor'},
        s = {':ISwapWith<CR>', 'Swap elements'},
        t = {':TableModeToggle<CR>', 'Toggle table mode'},
        v = {
            function()
                local venn_enabled = vim.inspect(vim.b.venn_enabled)
                if venn_enabled == 'nil' then
                    vim.b.venn_enabled = true
                    api.nvim_command('setlocal virtualedit=all')
                    -- Draw lines with WASD keystroke
                    api.nvim_buf_set_keymap(0, 'n', 'A', '<C-v>h:VBox<CR>', opts)
                    api.nvim_buf_set_keymap(0, 'n', 'S', '<C-v>j:VBox<CR>', opts)
                    api.nvim_buf_set_keymap(0, 'n', 'W', '<C-v>k:VBox<CR>', opts)
                    api.nvim_buf_set_keymap(0, 'n', 'D', '<C-v>l:VBox<CR>', opts)
                    -- Draw boxes by pressing 'f' with visual selection
                    api.nvim_buf_set_keymap(0, 'v', 'f', ':VBox<CR>', opts)
                    notify('Virtual box edit enabled.', vim.log.levels.INFO)
                else
                    vim.b.venn_enabled = nil
                    api.nvim_command('setlocal virtualedit=block')
                    api.nvim_buf_del_keymap(0, 'v', 'f')
                    api.nvim_buf_del_keymap(0, 'n', 'A')
                    api.nvim_buf_del_keymap(0, 'n', 'S')
                    api.nvim_buf_del_keymap(0, 'n', 'W')
                    api.nvim_buf_del_keymap(0, 'n', 'D')
                    notify('Virtual box edit disabled.', vim.log.levels.INFO)
                end
            end,
            'Toggle virtual box edit'
        },
        z = {':ZenMode<CR>', 'Zen mode'},
        Z = {':Twilight<CR>', 'Twilight mode'}
    },
    f = {
        name = 'Telescope',
        a = {':Telescope autocommands<CR>', 'Autocommands'},
        b = {':Telescope buffers<CR>', 'Buffers'},
        c = {':Telescope commands<CR>', 'Commands'},
        d = {':Telescope projects<CR>', 'Recent directories'},
        e = {':Telescope file_browser<CR>', 'File browser'},
        f = {':Telescope find_files<CR>', 'Find files'},
        g = {':Telescope live_grep<CR>', 'Live grep'},
        h = {':Telescope help_tags<CR>', 'Help tags'},
        i = {':Telescope highlights<CR>', 'Highlight groups'},
        j = {
            name = 'Symbols',
            g = 'Gitmoji',
            h = {':Telescope symbols<CR>', 'All symbols'},
            j = 'Emoji',
            k = 'Kaomoji',
            l = 'Julia',
            m = 'Math symbols',
            n = 'Nerd-fonts symbols',
            t = 'Latex symbols'
        },
        k = {':Telescope keymaps<CR>', 'Normal keymaps'},
        l = {':Telescope notify<CR>', 'Notification history'},
        m = {':Telescope marks<CR>', 'Bookmarks'},
        n = {':Telescope man_pages<CR>', 'Man pages'},
        o = {':Telescope oldfiles<CR>', 'Recent files'},
        p = {':Telescope project display_type=full<CR>', 'Projects'},
        r = {':Telescope reloader<CR>', 'Reload lua modules'},
        s = {':Telescope treesitter<CR>', 'Treesitter'},
        t = {':TodoTelescope<CR>', 'Todo list'},
        u = {':Telescope current_buffer_fuzzy_find<CR>', 'Search current buffer'},
        v = {':Telescope vim_options<CR>', 'Vim options'},
        x = {
            name = 'Tasks',
            a = {':Telescope yabs tasks<CR>', 'All tasks'},
            g = {':Telescope yabs global_tasks<CR>', 'Global tasks'},
            l = {':Telescope yabs current_language_tasks<CR>', 'Tasks for current filetype'},
            t = {':YabsDefaultTask<CR>', 'Run default task'}
        },
        y = {':Telescope filetypes<CR>', 'Filetypes'},
        z = {':Telescope registers<CR>', 'Vim registers'}
    },
    g = {
        name = 'Git',
        a = {':Telescope git_stash<CR>', 'Stash'},
        b = 'Blame current line',
        c = {':Telescope git_bcommits<CR>', 'Buffer commits'},
        C = {':Telescope git_commits<CR>', 'Commits'},
        m = {':Telescope git_branches<CR>', 'Branches'},
        n = {':Neogit<CR>', 'Neogit'},
        p = 'Preview hunk',
        r = 'Reset hunk',
        R = 'Reset all hunks in buffer',
        s = 'Stage hunk',
        S = 'Stage buffer',
        t = {':Telescope git_status<CR>', 'Status'},
        u = 'Undo hunk',
        U = 'Reset buffer index',
        y = 'Get remote url for cursorline',
        Y = 'Get remote url'
    },
    j = {
        name = 'Translate',
        t = {':Trans<CR>', 'Translate'},
        d = {':TransSelectDirection<CR>', 'Translate with direction'},
        r = {'cw<C-R>=system(\'trans -brief -no-ansi\', getreg(""))[:-2]<CR>', 'Translate and replace'},
        c = {'cw<C-R>=system(\'trans -brief -no-ansi :\', getreg(""))[:-2]<S-Left><S-Left><Right>', 'Translate and replace with direction'}
    },
    n = {':NvimTreeToggle<CR>', 'NvimTree'},
    p = {
        name = 'Find/Replace',
        o = 'Open spectre',
        p = 'Search in current file',
        w = 'Find/Replace cursorword'
    },
    r = {
        name = 'REST',
        c = {'<Plug>RestNvim', 'Run request under cursor'},
        p = {'<Plug>RestNvimPreview', 'Preview request cURL command'},
        l = {'<Plug>RestNvimLast', 'Re-run last request'}
    },
    s = {
        name = 'Session',
        s = 'Save session for current directory',
        d = 'Stop automatically saving',
        l = 'Load last session',
        r = 'Load session for current directory'
    },
    w = {':WindowPick<CR>', 'Pick window'}
}

local visual_leader_mappings = {
    e = {
        name = 'Editor',
        a = {':EasyAlign<CR>', 'Range align'}
    },
    d = {
        name = 'DAP',
        e = 'Hover on range (UI)'
    },
    g = {
        name = 'Git',
        r = 'Reset hunk',
        s = 'Stage hunk',
        y = 'Get remote url for range'
    },
    j = {
        name = 'Translate',
        t = {':Trans<CR>', 'Translate'},
        d = {':TransSelectDirection<CR>', 'Translate with direction'},
        r = {'c<C-R>=system(\'trans -brief -no-ansi\', getreg(""))[:-2]<CR>', 'Translate and replace'},
        c = {'c<C-R>=system(\'trans -brief -no-ansi :\', getreg(""))[:-2]<S-Left><S-Left><Right>', 'Translate and replace with direction'}
    },
    p = 'Find/Replace'
}

local function undefined_mappings()
    -- Escape to normal mode in terminal buffer
    api.nvim_set_keymap('t', '<Esc>', '<C-\\><C-n>', opts)
    -- Continuous indent
    api.nvim_set_keymap('v', '<', '<gv', opts)
    api.nvim_set_keymap('v', '>', '>gv', opts)
    -- Also move up/down virtual lines (:set wrap)
    api.nvim_set_keymap('n', 'j', 'v:count == 0 ? "gj" : "j"', {noremap = true, expr = true, silent = true})
    api.nvim_set_keymap('n', 'k', 'v:count == 0 ? "gk" : "k"', {noremap = true, expr = true, silent = true})
    -- winshift.nvim
    api.nvim_set_keymap('n', '<C-w><C-m>', ':WinShift<CR>', opts)
    api.nvim_set_keymap('n', '<C-w>m', ':WinShift<CR>', opts)
    api.nvim_set_keymap('n', '<C-A-h>', ':WinShift left<CR>', opts)
    api.nvim_set_keymap('n', '<C-A-j>', ':WinShift down<CR>', opts)
    api.nvim_set_keymap('n', '<C-A-k>', ':WinShift up<CR>', opts)
    api.nvim_set_keymap('n', '<C-A-l>', ':WinShift right<CR>', opts)
end

function M.setup()
    undefined_mappings()
    wk.register(normal_mappings)
    wk.register(normal_leader_mappings, {prefix = '<leader>'})
    wk.register(visual_leader_mappings, {mode = 'v', prefix = '<leader>'})
end

--------------------
-- Local mappings --
--------------------
function WhichkeyLocal()
    local bufnr = api.nvim_get_current_buf()
    wk.register({
        c = {':ColorizerToggle<CR>', 'Colorizer'},
        d = {
            name = 'Delete',
            a = {':BDelete all<CR>', 'All buffers'},
            d = {':BDelete this<CR>', 'Current buffer'},
            h = {':BDelete hidden<CR>', 'Hidden buffers'},
            n = {':BDelete nameless<CR>', 'Buffers without name'},
            o = {':BDelete other<CR>', 'Other buffers'}
        },
        j = {':BufferLineCyclePrev<CR>', 'Previous buffer'},
        k = {':BufferLineCycleNext<CR>', 'Next buffer'},
        n = {':enew<CR>', 'New buffer'},
        u = {':UndotreeToggle<CR>', 'Undotree'}
    }, {buffer = bufnr, prefix = '<localleader>'})
end

function WhichkeyMarkdown()
    wk.register({
        p = {':MarkdownPreviewToggle<CR>', 'Preview markdown'}
    }, {buffer = api.nvim_get_current_buf(), prefix = '<localleader>'})
end

function WhichkeyHtml()
    wk.register({
        p = {':Bracey<CR>', 'Preview html'}
    }, {buffer = api.nvim_get_current_buf(), prefix = '<localleader>'})
end

function WhichkeyOrg()
    wk.register({
        ['<leader>o'] = {
            name = 'Org',
            a = 'Agenda',
            A = 'Toggle ARCHIVE',
            c = 'Capture',
            e = 'Export',
            i = {
                name = 'Insert',
                h = 'Add headline',
                t = 'Add TODO heading and content',
                T = 'Add TODO heading'
            },
            J = 'Move subtree down',
            K = 'Move subtree up',
            o = 'Open at point',
            r = 'Refile',
            t = 'Set tags',
            ['$'] = 'Archive current headline'
        },
        ['<leader><CR>'] = 'Org meta return',
        ['<C-a>'] = 'Org increase date',
        ['<C-x>'] = 'Org decrease date',
        ['cid'] = 'Org change date',
        ['cit'] = 'Org TODO',
        ['ciT'] = 'Org TODO prev',
        ['<C-Space>'] = 'Org toggle checkbox',
        ['<TAB>'] = 'Org cycle folding',
        ['<S-TAB>'] = 'Org cycle global folding',
        ['<<'] = 'Org promote headline',
        ['>>'] = 'Org demote headline',
        ['<s'] = 'Org prmote subtree',
        ['>s'] = 'Org demote subtree',
        ['}'] = 'Org next visible heading',
        ['{'] = 'Org previous visible heading',
        [']]'] = 'Org forward heading',
        ['[['] = 'Org backward heading',
        ['g{'] = 'Org parent heading',
        ['?'] = 'Org help'
    }, {buffer = api.nvim_get_current_buf()})
end

-----------------------
-- Plugins' mappings --
-----------------------
function M.treesitter()
    local mappings = {
        ['['] = {
            m = 'Previous start of outer class',
            M = 'Previous end of outer class',
            ['['] = 'Previous start of outer function',
            [']'] = 'Previous end of outer function'
        },
        [']'] = {
            m = 'Next start of outer class',
            M = 'Next end of outer class',
            ['['] = 'Next start of outer function',
            [']'] = 'Next end of outer function'
        },
        g = {
            n = {
                name = 'Treesitter',
                d = 'Goto definition',
                D = 'List definitions',
                i = 'Initialize selection',
                j = 'Goto previous usage',
                k = 'Goto next usage',
                o = 'List definitions TOC',
                r = 'Rename within scope'
            }
        }
    }
    local visual_mappings = {
        a = {
            c = 'Outer class',
            f = 'Outer function'
        },
        i = {
            c = 'Inner class',
            f = 'Inner function'
        },
        g = {
            n = {
                name = 'Treesitter',
                n = 'Increment node',
                s = 'Increment scope',
                m = 'Decrement node'
            }
        }
    }

    wk.register(mappings)
    wk.register(visual_mappings, {mode = 'v'})
end

function M.eft()
    api.nvim_set_keymap('n', 'f', '<Plug>(eft-f)', {silent = true})
    api.nvim_set_keymap('x', 'f', '<Plug>(eft-f)', {silent = true})
    api.nvim_set_keymap('n', 'F', '<Plug>(eft-F)', {silent = true})
    api.nvim_set_keymap('x', 'F', '<Plug>(eft-F)', {silent = true})
    api.nvim_set_keymap('n', 't', '<Plug>(eft-t)', {silent = true})
    api.nvim_set_keymap('x', 't', '<Plug>(eft-t)', {silent = true})
    api.nvim_set_keymap('n', 'T', '<Plug>(eft-T)', {silent = true})
    api.nvim_set_keymap('x', 'T', '<Plug>(eft-T)', {silent = true})
    api.nvim_set_keymap('n', ';', '<Plug>(eft-repeat)', {silent = true})
    api.nvim_set_keymap('x', ';', '<Plug>(eft-repeat)', {silent = true})
end

function M.dial()
    api.nvim_set_keymap('n', '<C-a>', '<Plug>(dial-increment)', {silent = true})
    api.nvim_set_keymap('v', '<C-a>', '<Plug>(dial-increment)', {silent = true})
    api.nvim_set_keymap('n', '<C-x>', '<Plug>(dial-decrement)', {silent = true})
    api.nvim_set_keymap('v', '<C-x>', '<Plug>(dial-decrement)', {silent = true})
    api.nvim_set_keymap('v', 'g<C-a>', '<Plug>(dial-increment-additional)', {silent = true})
    api.nvim_set_keymap('v', 'g<C-x>', '<Plug>(dial-decrement-additional)', {silent = true})
end

function M.neogen()
    api.nvim_set_keymap('n', '<leader>eg', ':lua require("neogen").generate()<CR>', opts)
    api.nvim_set_keymap('n', '<C-e>', ':lua require("neogen").jump_next()<CR>', opts)
end

function M.gitlinker()
    api.nvim_set_keymap('n', '<leader>gY', ':lua require("gitlinker").get_repo_url()<CR>', opts)
end

function M.dap()
    api.nvim_set_keymap('n', '<leader>dn', ':lua require("dap").continue()<CR>', opts)
    api.nvim_set_keymap('n', '<leader>dd', ':lua require("dap").disconnect()<CR>', opts)
    api.nvim_set_keymap('n', '<leader>db', ':lua require("dap").toggle_breakpoint()<CR>', opts)
    api.nvim_set_keymap('n', '<leader>dB', ':lua require("dap").set_breakpoint(vim.fn.input("Breakpoint condition: "))<CR>', opts)
    api.nvim_set_keymap('n', '<leader>dl', ':lua require("dap").list_breakpoints()<CR>', opts)
    api.nvim_set_keymap('n', '<leader>dc', ':lua require("dap").run_to_cursor()<CR>', opts)
    api.nvim_set_keymap('n', '<leader>dz', ':lua require("dap").run_last()<CR>', opts)
    api.nvim_set_keymap('n', '<F9>', ':lua require("dap").step_over()<CR>', opts)
    api.nvim_set_keymap('n', '<leader>dv', ':lua require("dap").step_over()<CR>', opts)
    api.nvim_set_keymap('n', '<F10>', ':lua require("dap").step_into()<CR>', opts)
    api.nvim_set_keymap('n', '<leader>di', ':lua require("dap").step_into()<CR>', opts)
    api.nvim_set_keymap('n', '<F11>', ':lua require("dap").step_out()<CR>', opts)
    api.nvim_set_keymap('n', '<leader>do', ':lua require("dap").step_out()<CR>', opts)
    api.nvim_set_keymap('n', '<leader>dr', ':lua require("dap").repl.open()<CR>', opts)
end

function M.dapui()
    api.nvim_set_keymap('n', '<leader>de', ':lua require("dapui").eval()<CR>', opts)
    api.nvim_set_keymap('v', '<leader>de', ':lua require("dapui").eval()<CR>', opts)
    api.nvim_set_keymap('n', '<leader>df', ':lua require("dapui").float_element()<CR>', opts)
    api.nvim_set_keymap('n', '<leader>dt', ':lua require("dapui").toggle()<CR>', opts)
end

function M.telescope_symbols()
    api.nvim_set_keymap('n', '<leader>fjg', ':lua require("telescope.builtin").symbols{sources = {"gitmoji"}, prompt_title = "Gitmoji"}<CR>', opts)
    api.nvim_set_keymap('n', '<leader>fjj', ':lua require("telescope.builtin").symbols{sources = {"emoji"}, prompt_title = "Emoji"}<CR>', opts)
    api.nvim_set_keymap('n', '<leader>fjk', ':lua require("telescope.builtin").symbols{sources = {"kaomoji"}, prompt_title = "Kaomoji"}<CR>', opts)
    api.nvim_set_keymap('n', '<leader>fjl', ':lua require("telescope.builtin").symbols{sources = {"julia"}, prompt_title = "Julia symbols"}<CR>', opts)
    api.nvim_set_keymap('n', '<leader>fjm', ':lua require("telescope.builtin").symbols{sources = {"math"}, prompt_title = "Math symbols"}<CR>', opts)
    api.nvim_set_keymap('n', '<leader>fjn', ':lua require("telescope.builtin").symbols{sources = {"nerd"}, prompt_title = "Nerd-fonts symbols"}<CR>', opts)
    api.nvim_set_keymap('n', '<leader>fjt', ':lua require("telescope.builtin").symbols{sources = {"latex"}, prompt_title = "Latex symbols"}<CR>', opts)
end

function M.spectre()
    api.nvim_set_keymap('n', '<leader>po', ':lua require("spectre").open()<CR>', opts)
    api.nvim_set_keymap('n', '<leader>pp', 'viw:lua require("spectre").open_file_search()<CR>', opts)
    api.nvim_set_keymap('n', '<leader>pw', ':lua require("spectre").open_visual({select_word = true})<CR>', opts)
    api.nvim_set_keymap('v', '<leader>p', ':lua require("spectre").open_visual()<CR>', opts)
end

function M.persistence()
    api.nvim_set_keymap('n', '<leader>ss', ':lua require("persistence").save()<CR>', opts)
    api.nvim_set_keymap('n', '<leader>sd', ':lua require("persistence").stop()<CR>', opts)
    api.nvim_set_keymap('n', '<leader>sl', ':lua require("persistence").load({last = true})<CR>', opts)
    api.nvim_set_keymap('n', '<leader>sr', ':lua require("persistence").load()<CR>', opts)
end

return M