--=============================================================================
-- compatible.lua --- compatible api between neovim/vim
-- Copyright (c) 2016-2019 Wang Shidong & Contributors
-- Author: Wang Shidong < wsdjeg@outlook.com >
-- URL: https://spacevim.org
-- License: GPLv3
--=============================================================================
local M = {}

local system = require('spacevim.api').import('system')

function M.eval(l)
    if vim.api ~= nil then
        return vim.api.nvim_eval(l)
    else
        return vim.eval(l)
    end
end

if vim.command ~= nil then
    function M.cmd(command)
        return vim.command(command)
    end
else
    function M.cmd(command)
        return vim.api.nvim_command(command)
    end
end

-- there is no want to call viml function in old vim and neovim

local function build_argv(...)
    local str = ''
    for index, value in ipairs(...) do
        if str ~= '' then
            str = str .. ','
        end
        if type(value) == 'string' then
            str = str .. '"' .. value .. '"'
        elseif type(value) == 'number' then
            str = str .. value
        end
    end
    return str
end

function M.call(funcname, ...)
    if vim.call ~= nil then
        return vim.call(funcname, ...)
    else
        if vim.api ~= nil then
            return vim.api.nvim_call_function(funcname, {...})
        else
            -- call not call vim script function in lua
            vim.command('let g:lua_rst = ' .. funcname .. '(' .. build_argv({...}) .. ')')
            return M.eval('g:lua_rst')
        end
    end
end

-- this is for Vim and old neovim
M.fn = setmetatable({}, {
    __index = function(t, key)
        local _fn
        if vim.api ~= nil and vim.api[key] ~= nil then
            _fn = function()
                error(string.format("Tried to call API function with vim.fn: use vim.api.%s instead", key))
            end
        else
            _fn = function(...)
                return M.call(key, ...)
            end
        end
        t[key] = _fn
        return _fn
    end
})

-- This is for vim and old neovim to use vim.o
M.vim_options = setmetatable({}, {
    __index = function(t, key)
        local _fn
        if vim.api ~= nil then
            -- for neovim
            return vim.api.nvim_get_option(key)
        else
            -- for vim
            _fn = M.eval('&' .. key)
        end
        t[key] = _fn
        return _fn
    end
})

function M.echo(msg)
    if vim.api ~= nil then
        vim.api.nvim_echo({{msg}}, false, {})
    else
        vim.command('echo ' .. build_argv({msg}))
    end
end

local has_cache = {}

function M.has(feature)
    if has_cache[feature] ~= nil then
        return has_cache[feature]
    else
        return M.eval('float2nr(has("' .. feature .. '"))')
    end
end

if M.has('patch-7.4.279') then
    function M.globpath(dir, expr)
        return M.fn.globpath(dir, expr, 1, 1)
    end
else
    function M.globpath(dir, expr)
        return M.fn.split(fn.globpath(dir, expr), "\n")
    end
end

function M.execute(cmd, silent)
    return  M.fn.execute(cmd, silent)
end

return M