local health, fn = vim.health, vim.fn

local ok         = health.report_ok
local warn       = health.report_warn
local error      = health.report_error
local has        = fn.has
local executable = fn.executable

local function check_neovim_version()
    if has("nvim-0.9") == 1 then
        ok([[You have [neovim-nightly] ]])
    else
        warn([[Trans Title requires Neovim 0.9 or newer
        See neovim-nightly: [https://github.com/neovim/neovim/releases/tag/nightly]
        ]])
    end
end

local function check_plugin_dependencies()
    local plugin_dependencies = {
        -- 'plenary',
        "sqlite",
    }

    for _, dep in ipairs(plugin_dependencies) do
        if pcall(require, dep) then
            ok(string.format("Dependency [%s] is installed", dep))
        else
            error(string.format("Dependency [%s] is not installed", dep))
        end
    end
end

local function check_binary_dependencies()
    local binary_dependencies = {
        "curl",
        "sqlite3",
    }

    if has("linux") == 1 then
        binary_dependencies[3] = "festival"
    elseif has("mac") == 1 then
        binary_dependencies[3] = "say"
    else
        binary_dependencies[3] = "node"
    end

    for _, dep in ipairs(binary_dependencies) do
        if executable(dep) == 1 then
            ok(string.format("Binary dependency [%s] is installed", dep))
        else
            error(string.format("Binary dependency [%s] is not installed", dep))
        end
    end
end

local function check_database()
    local db_path = require("Trans").conf.dir .. "/ultimate.db"
    if fn.filereadable(db_path) == 1 then
        ok([[ultimate database found ]])
    else
        error([[Stardict database not found
        [Manually]: Please check the doc in github: [https://github.com/JuanZoran/Trans.nvim]
        [Automatically]: Try to run `:lua require "Trans".install()`
        ]])
    end
end

local function check_configure_file()
    local path = fn.expand(require("Trans").conf.dir .. "/Trans.json")
    if not fn.filereadable(path) then
        warn("Backend configuration file[%s] not found")
    end

    local file = io.open(path, "r")
    local valid = file and pcall(vim.json.decode, file:read("*a"))

    if valid then
        ok(string.format([[Backend configuration file [%s] found and valid ]], path))
    else
        error(string.format(
            [[Backend configuration file [%s] invalid
        Please check the doc in github: [https://github.com/JuanZoran/Trans.nvim]
        ]],
            path
        ))
    end
end

local function check()
    check_database()
    check_neovim_version()
    check_configure_file()
    check_plugin_dependencies()
    check_binary_dependencies()
end

return { check = check }