-- 不能正常工作的括号补全代码
-- 完全由ai生成qwq
--
local M = {}

-- 定义需要自动补全的字符对
local pairs_map = {
    ['('] = ')',
    ['['] = ']',
    ['{'] = '}',
    ["'"] = "'",
    ['"'] = '"',
    ['`'] = '`',
    ['<'] = '>',
}


-- 检查光标前是否是转义字符
local function is_escaped()
    local col = vim.api.nvim_win_get_cursor(0)[2]
    local line = vim.api.nvim_get_current_line()
    local count = 0
    while col > 0 and line:sub(col, col) == '\\' do
        count = count + 1
        col = col - 1
    end
    return count % 2 == 1
end

-- 检查是否在注释或字符串中
local function is_in_comment_or_string()
    local synstack = vim.fn.synstack(vim.fn.line('.'), vim.fn.col('.'))
    for _, id in ipairs(synstack) do
        local syn = vim.fn.synIDattr(id, 'name')
        if string.find(syn, 'comment') or string.find(syn, 'string') then
            return true
        end
    end
    return false
end

local function should_auto_pair(left, right)
    local line = vim.api.nvim_get_current_line()
    local col = vim.api.nvim_win_get_cursor(0)[2]
    local next_char = line:sub(col + 1, col + 1)

    -- 特殊处理引号：如果下一个字符是字母/数字，不自动补全
    if left == "'" or left == '"' or left == '`' then
        if next_char:match('%w') then
            return false
        end
    end

    return next_char == '' or next_char:match('%s') or next_char == right
end

local function auto_pair(left)
    local right = pairs_map[left]
    if should_auto_pair(left, right) then
        local keys = left .. right .. '<Left>'
        return vim.api.nvim_replace_termcodes(keys, true, true, true)
    end
    return left
end

-- 修改右括号处理函数
local function handle_right_pair(right)
    local line = vim.api.nvim_get_current_line()
    local col = vim.api.nvim_win_get_cursor(0)[2]
    local next_char = line:sub(col + 1, col + 1)
    
    -- 只有当下一个字符确实是配对的右括号时才跳过
    if next_char == right then
        -- 检查前面是否有未闭合的左括号
        local before_cursor = line:sub(1, col)
        local after_cursor = line:sub(col + 1)
        
        -- 计算前面左括号和后面右括号的数量
        local left_count = select(2, before_cursor:gsub(vim.pesc(pairs_map[right]), ''))
        local right_count = select(2, after_cursor:gsub(vim.pesc(right), ''))
        
        -- 只有当前面有未闭合的左括号时才跳过
        if left_count > right_count then
            return vim.api.nvim_replace_termcodes('<Right>', true, true, true)
        end
    end
    return right
end


-- 主函数，处理自动补全
function M.setup()
    vim.keymap.set('i', '<BS>', function()
        return M.auto_pairs_bs()
    end, {expr = true, noremap = true})

    for left, right in pairs(pairs_map) do
        vim.keymap.set('i', left, function()
            if is_escaped() or is_in_comment_or_string(left) then
                return left
            end
            return auto_pair(left)
        end, {expr = true, noremap = true})

        -- 设置右符号
        vim.keymap.set('i', right, function()
            if is_escaped() or is_in_comment_or_string() then
                return right
            end
            return handle_right_pair(right)
        end, {expr = true, noremap = true})
    end
end

-- 退格键处理
function M.auto_pairs_bs()
    local line = vim.fn.getline('.')
    local col = vim.fn.col('.')  -- 获取 1-based 列号

    local prev_char = line:sub(col-1, col-1)
    local next_char = line:sub(col, col)

    for left, right in pairs(pairs_map) do
        if prev_char == left and next_char == right then
            return '<Del><BS>'
        end
    end

    return '<BS>'
end

return M