local Rule = require('nvim-autopairs.rule')
local npairs = require('nvim-autopairs')
local cond = require('nvim-autopairs.conds')

npairs.setup({
    -- will ignore alphanumeric and `.` symbol
    ignored_next_char = "[%w%.]",
})

npairs.add_rules({
        Rule("\\(", "\\)", { "tex", "latex" }),
        Rule("\\[", "\\]", { "tex", "latex" }),
    },
    -- disable for .vim files, but it work for another filetypes
    Rule("a", "a", "-vim")
)

-- Add spaces between brackets
local brackets = { { '(', ')' }, { '[', ']' }, { '{', '}' } }
npairs.add_rules {
    -- Rule for a pair with left-side ' ' and right side ' '
    Rule(' ', ' ')
    -- Pair will only occur if the conditional function returns true
        :with_pair(function(opts)
            -- We are checking if we are inserting a space in (), [], or {}
            local pair = opts.line:sub(opts.col - 1, opts.col)
            return vim.tbl_contains({
                brackets[1][1] .. brackets[1][2],
                brackets[2][1] .. brackets[2][2],
                brackets[3][1] .. brackets[3][2]
            }, pair)
        end)
        :with_move(cond.none())
        :with_cr(cond.none())
    -- We only want to delete the pair of spaces when the cursor is as such: ( | )
        :with_del(function(opts)
            local col = vim.api.nvim_win_get_cursor(0)[2]
            local context = opts.line:sub(col - 1, col + 2)
            return vim.tbl_contains({
                brackets[1][1] .. '  ' .. brackets[1][2],
                brackets[2][1] .. '  ' .. brackets[2][2],
                brackets[3][1] .. '  ' .. brackets[3][2]
            }, context)
        end)
}
-- For each pair of brackets we will add another rule
for _, bracket in pairs(brackets) do
    npairs.add_rules {
        -- Each of these rules is for a pair with left-side '( ' and right-side ' )' for each bracket type
        Rule(bracket[1] .. ' ', ' ' .. bracket[2])
            :with_pair(cond.none())
            :with_move(function(opts) return opts.char == bracket[2] end)
            :with_del(cond.none())
            :use_key(bracket[2])
        -- Removes the trailing whitespace that can occur without this
            :replace_map_cr(function(_) return '<C-c>2xi<CR><C-c>O' end)
    }
end

-- Add space around =
npairs.add_rules {
    Rule('=', '', { "-tex", "-vim", "-sh", "-dockerfile", "-make", "-html" })
        :with_pair(cond.not_inside_quote())
        :with_pair(function(opts)
            local last_char = opts.line:sub(opts.col - 1, opts.col - 1)
            if last_char:match('[%w%=%s]') then
                return true
            end
            return false
        end)
        :replace_endpair(function(opts)
            local prev_2char = opts.line:sub(opts.col - 2, opts.col - 1)
            local next_char = opts.line:sub(opts.col, opts.col)
            next_char = next_char == ' ' and '' or ' '
            if prev_2char:match('%w$') then
                return '<bs> =' .. next_char
            end
            if prev_2char:match('%=$') then
                return next_char
            end
            if prev_2char:match('=') then
                return '<bs><bs>=' .. next_char
            end
            return ''
        end)
        :set_end_pair_length(0)
        :with_move(cond.none())
        :with_del(cond.none())
}

-- Insertion with surrounding check
function rule2(a1, ins, a2, lang)
    npairs.add_rule(
        Rule(ins, ins, lang)
        :with_pair(function(opts) return a1 .. a2 == opts.line:sub(opts.col - #a1, opts.col + #a2 - 1) end)
        :with_move(cond.none())
        :with_cr(cond.none())
        :with_del(function(opts)
            local col = vim.api.nvim_win_get_cursor(0)[2]
            return a1 .. ins .. ins .. a2 ==
                opts.line:sub(col - #a1 - #ins + 1, col + #ins + #a2) -- insert only works for #ins == 1 anyway
        end)
    )
end

-- Only use it for ocaml
rule2('(', '*', ')', 'ocaml')
rule2('(*', ' ', '*)', 'ocaml')
rule2('(', ' ', ')')