local Rule = require("nvim-autopairs.rule")
local cond = require("nvim-autopairs.conds")
local npairs = require("nvim-autopairs")
local cmp = require("cmp")
local cmp_autopairs = require("nvim-autopairs.completion.cmp")

local langs = {
    haskell_like = { "haskell", "nix", "ruler" },
    ml_like = { "ocaml", "why3", "skel", "isabelle" },
    html_like = { "html", "htmldjango" },
    latex_like = { "typst", "latex" },
    lisps = { "fennel", "clojure", "lisp", "racket", "scheme" },

    has_bracket = { "typst", "python", "haskell", "nix", "sh" },
    c_style_block_comment = { "typst", "go", "java", "rust", "rust", "scss", "nix" },

    all = nil,
}

npairs.setup {
    disable_filetype = langs.lisps,
}
cmp.event:on("confirm_done", cmp_autopairs.on_confirm_done())

local function has_pair_on_line(opts, pattern) return select(2, opts.line:gsub(pattern, "")) % 2 == 0 end

local function pair_with_insertion(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

for _, punct in pairs { ",", ";" } do
    npairs.add_rule(
        Rule("", punct)
            :with_move(function(opts) return opts.char == punct end)
            :with_pair(function() return false end)
            :with_del(function() return false end)
            :with_cr(function() return false end)
            :use_key(punct)
    )
end

pair_with_insertion("(", "*", ")", langs.ml_like)
pair_with_insertion("(*", " ", "*)", langs.ml_like)

pair_with_insertion("[", " ", "]", langs.has_bracket)
pair_with_insertion("{", " ", "}", langs.all)

npairs.add_rules {
    Rule("/*", "*/", { "typst", "go", "rust", "scss", "nix" }):with_del(cond.done()):with_move(cond.none()), -- allow java doc
}
pair_with_insertion("/*", " ", "*/", langs.c_style_block_comment)

pair_with_insertion("{", "#", "}", langs.html_like)
pair_with_insertion("{#", " ", "#}", langs.html_like)
pair_with_insertion("{#", "-", "#}", langs.html_like)
pair_with_insertion("{#-", " ", "-#}", langs.html_like)

pair_with_insertion("{", "%", "}", langs.html_like)
pair_with_insertion("{%", " ", "%}", langs.html_like)
pair_with_insertion("{%", "-", "%}", langs.html_like)
pair_with_insertion("{%-", " ", "-%}", langs.html_like)

pair_with_insertion("{{", " ", "}}", langs.html_like)
pair_with_insertion("{{", "-", "}}", langs.html_like)
pair_with_insertion("{{-", " ", "-}}", langs.html_like)

npairs.add_rules {
    Rule("$", "$", "typst")
        :with_pair(function(opts) return has_pair_on_line(opts, "%$") end)
        :with_del(function(opts) return has_pair_on_line(opts, "%$") end)
        :with_move(cond.done()),
}
pair_with_insertion("$", " ", "$", langs.latex_like)

pair_with_insertion("{", "-", "}", langs.haskell_like)
pair_with_insertion("{-", " ", "-}", langs.haskell_like) -- block comment
pair_with_insertion("{-", "#", "-}", langs.haskell_like) -- language flags
pair_with_insertion("{-#", " ", "#-}", langs.haskell_like)
pair_with_insertion("(", " ", ")", langs.haskell_like)

npairs.add_rules {
    Rule("<", ">", langs.html_like)
        :with_pair(function(opts) return has_pair_on_line(opts, "[<>]") end)
        :with_del(function(opts) return has_pair_on_line(opts, "[<>]") end)
        :with_move(function(opts) return opts.char == ">" end),
}