Diagnostic

vim.diagnostic.severity.ERROR
vim.diagnostic.severity.WARN
vim.diagnostic.severity.INFO
vim.diagnostic.severity.HINT

vim.diagnostic.get(0, { severity = vim.diagnostic,severity.WARN })
vim.diagnostic.get(0, { severity = { min = vim.diagnostic.severity.WARN }})
vim.diagnostic.get(0, { severity = { vim.diagnostic.severity.WARN, vim.diagnostic.severity.INFO }})

function M.show(namespace, bufnr, diagnostics, opts)
    vim.validate("namespace", namespace, "number", true)
    vim.validate("bufnr", bufnr, "number", true)
    vim.validate("diagnostics", diagnostics, vim.islist, true, "a list of diagnostics")
    vim.validate("opts", opts, "table", true)

    if not bufnr or not namespace then
        assert(not diagnostics, "Cannot show diagnostics without a buffer and namespace")
        if not bufnr then
            for iter_bufnr in pairs(diagnostic_cache) do
                M.show(namespace, iter_bufnr, nil, opts)
            end
        else
            -- namespace is nil
            bufnr = vim._resolve_bufnr(bufnr)
            for iter_namespace in pairs(diagnostic_cache[bufnr]) do
                M.show(iter_namespace, bufnr, nil, opts)
            end
        end
        return
    end

    if not M.is_enabled({ bufnr = bufnr or 0, ns_id = namespace }) then
        return
    end

    M.hide(namespace, bufnr)

    diagnostics = diagnostics or get_diagnostics(bufnr, { namespace = namespace }, true)

    if vim.tbl_isempty(diagnostics) then
        return
    end

    local opts_res = get_resolved_options(opts, namespace, bufnr)

    if opts_res.update_in_insert then
        clear_scheduled_display(namespace, bufnr)
    else
        local mode = api.nvim_get_mode()
        if mode.mode:sub(1, 1) == "i" then
            schedule_display(namespace, bufnr, opts_res)
            return
        end
    end

    if opts_res.severity_sort then
        if type(opts_res.severity_sort) == "table" and opts_res.severity_sort.reverse then
            table.sort(diagnostics, function(a, b)
                return a.severity < b.severity
            end)
        else
            table.sort(diagnostics, function(a, b)
                return a.severity > b.severity
            end)
        end
    end

    for handler_name, handler in pairs(M.handlers) do
        if handler.show and opts_res[handler_name] then
            local filtered = filter_by_severity(opts_res[handler_name].severity, diagnostics)
            handler.show(namespace, bufnr, filtered, opts_res)
        end
    end
end

 vim.diagnostic.config({
    -- 这两个是默认内置处理器
    virtual_text = { prefix = "■" }, -- 配置 virtual_text 处理器
    signs = { severity = vim.diagnostic.severity.ERROR } -- 仅显示错误级诊断
 })

-- 定义浮动窗口处理器
local float_handler = {
  show = function(namespace, bufnr, diagnostics, opts)
    -- 仅在光标悬停时触发
    vim.api.nvim_create_autocmd("CursorHold", {
      buffer = bufnr,
      callback = function()
        local diag = vim.diagnostic.get(bufnr, { lnum = vim.fn.line(".") - 1 })[1]
        if diag then
          vim.diagnostic.open_float({ scope = "line" })
        end
      end
    })
  end,
  hide = function(namespace, bufnr)
    vim.api.nvim_clear_autocmds({ event = "CursorHold", buffer = bufnr })
  end
}

-- 注册并启用
vim.diagnostic.handlers.my_float = float_handler
vim.diagnostic.config({ my_float = true }) -- 启用自定义处理器

-- 使用vim.notify提示当前buffer中ERROR诊断数目
vim.diagnostic.handlers["my/notify"] = {
    show = function(namespace, bufnr, diagnostics, opts)
        -- In our example, the opts table has a "log_level" option
        local level = opts["my/notify"].log_level
        local name = vim.diagnostic.get_namespace(namespace).name
        local msg = string.format("%d diagnostics in buffer %d from %s", #diagnostics, bufnr, name)
        vim.notify(msg, level)
    end,
}
-- Users can configure the handler
vim.diagnostic.config({
    ["my/notify"] = {
        log_level = vim.log.levels.INFO,
        -- This handler will only receive "error" diagnostics.
        severity = vim.diagnostic.severity.ERROR,
    },
})

local ns = vim.api.nvim_create_namespace("my_namespace")
local orig_signs_handler = vim.diagnostic.handlers.signs
vim.diagnostic.handlers.signs = {
    show = function(_, bufnr, _, opts)
        -- 获取当前缓冲区所有诊断
        local diagnostics = vim.diagnostic.get(bufnr)

        -- 按行筛选最严重诊断
        local max_severity_per_line = {}
        for _, d in pairs(diagnostics) do
            local m = max_severity_per_line[d.lnum]
            if not m or d.severity < m.severity then
                max_severity_per_line[d.lnum] = d
            end
        end

        -- 将过滤后的诊断传递给原始处理器
        local filtered_diagnostics = vim.tbl_values(max_severity_per_line)
        orig_signs_handler.show(ns, bufnr, filtered_diagnostics, opts)
    end,

    hide = function(_, bufnr)
        orig_signs_handler.hide(ns, bufnr)
    end,
}

-- 全局启用虚拟文本
vim.diagnostic.config({ virtual_text = true }) 
-- 为命名空间 ns1 单独禁用虚拟文本
vim.diagnostic.config({ virtual_text = false }, ns1)
-- 临时调用时覆盖配置：本次显示禁用虚拟文本
vim.diagnostic.show(ns1, bufnr, diagnostics, { virtual_text = false })

-- diagnostic
vim.diagnostic.config({
    virtual_lines = {
        severity = { min = vim.diagnostic.severity.WARN },
        current_line = true,
        format = function(diag)
            local severity_map = { [1] = "ERROR", [2] = "WARN", [3] = "INFO", [4] = "HINT" }
            return string.format("%s [%s] %s", diag.source, severity_map[diag.severity], diag.message)
        end,
    },
    severity_sort = true,
    float = {
        scope = "line",
        severity_sort = true,
        header = "Diagnostics",
        source = "if_many",
        format = function(diag)
            local severity_map = { [1] = "ERROR", [2] = "WARN", [3] = "INFO", [4] = "HINT" }
            return string.format("[%s] %s", severity_map[diag.severity], diag.message)
        end,
        border = "rounded", -- 使用内置圆角边框（直接生效）
    },
})

-- 2. 优化 float 窗口打开行为（通过自定义函数封装）
local function open_optimized_diagnostic_float()
    vim.diagnostic.open_float({
        -- 可选：限制窗口最大宽度/高度
        max_width = math.floor(vim.o.columns * 0.5), -- 最大宽度为屏幕50%
        max_height = math.floor(vim.o.lines * 0.4), -- 最大高度为屏幕40%
    })
end

vim.keymap.set("n", "<space>e", open_optimized_diagnostic_float, { desc = "Open optimized diagnostics" })