local M = {}

---@return boolean
local function check_mason()
    local ok, mason_version = pcall(require, "mason.version")
    if not ok then
        vim.health.error("mason.nvim was not found. Is it installed and loaded?")
        return false
    end
    if mason_version.MAJOR_VERSION ~= 2 then
        vim.health.error(("mason.nvim v2 is required (found v%d)."):format(mason_version.MAJOR_VERSION))
        return false
    end
    vim.health.ok("mason.nvim v2")
    return true
end

function M.check()
    vim.health.start("mason-conform.nvim")

    if vim.fn.has("nvim-0.11") == 1 then
        vim.health.ok("Neovim v0.11+")
    else
        vim.health.error("Neovim v0.11 or higher is required.")
    end

    local mason_installed = check_mason()

    if mason_installed then
        local registry_ok = pcall(require, "mason-registry")
        if registry_ok then
            vim.health.ok("mason registry is accessible")
        else
            vim.health.error("mason-registry could not be loaded.")
        end
    end

    local conform_ok = pcall(require, "conform")
    if not conform_ok then
        vim.health.error("conform.nvim was not found. Is it installed and loaded?")
        return
    end
    vim.health.ok("conform.nvim")

    local formatters = require("mason-conform.formatters").configured()
    if #formatters == 0 then
        vim.health.warn("No formatters are configured in conform's formatters_by_ft, so there is nothing to install.")
        return
    end
    vim.health.ok(("%d formatter(s) configured in formatters_by_ft"):format(#formatters))

    local mapping = require("mason-conform.mapping")
    local unmapped = {}
    for _, name in ipairs(formatters) do
        if mapping.conform_to_package[name] == nil then
            unmapped[#unmapped + 1] = name
        end
    end
    if #unmapped > 0 then
        vim.health.info(
            ("No mason package mapping for: %s. These will not be installed automatically."):format(
                table.concat(unmapped, ", ")
            )
        )
    end

    local ignored = {}
    for _, name in ipairs(require("mason-conform").config.ignore_install) do
        ignored[#ignored + 1] = name
    end
    if #ignored > 0 then
        vim.health.info(("Ignored by 'ignore_install': %s"):format(table.concat(ignored, ", ")))
    end
end

return M