local api = vim.api
---@class Trans
local Trans = require 'Trans'

---@class TransWindow
local window = {}

---Change window attached buffer
---@param buffer TransBuffer
function window:set_buf(buffer)
    api.nvim_win_set_buf(self.winid, buffer.bufnr)
    self.buffer = buffer
end

---Check window valid
---@return boolean
function window:is_valid()
    return api.nvim_win_is_valid(self.winid)
end

---Set window option
---@param name string option name
---@param value any
function window:set(name, value)
    if self:is_valid() then
        api.nvim_win_set_option(self.winid, name, value)
    end
end

---@param name string option name
---@return any
function window:option(name)
    return api.nvim_win_get_option(self.winid, name)
end

---@param height integer
function window:set_height(height)
    api.nvim_win_set_height(self.winid, height)
end

---@param width integer
function window:set_width(width)
    api.nvim_win_set_width(self.winid, width)
end

---Get window width
---@return integer
function window:width()
    return api.nvim_win_get_width(self.winid)
end

---Get window height
---@return integer
function window:height()
    return api.nvim_win_get_height(self.winid)
end

---Auto adjust window size
---@param height? integer max height
function window:adjust_height(height)
    local display_height = Trans.util.display_height(self.buffer:lines(), self:width())
    height = height and math.min(display_height, height) or display_height

    self:smooth_expand {
        field = 'height',
        to = height,
    }
end

---Expand window [width | height] value
---@param opts
---|{ field: 'width'|'height', to: integer}
function window:smooth_expand(opts)
    local field = opts.field -- width | height
    local from  = api['nvim_win_get_' .. field](self.winid)
    local to    = opts.to

    if from == to then return end

    local pause  = Trans.util.pause
    local method = api['nvim_win_set_' .. field]

    local wrap   = self:option 'wrap'
    self:set('wrap', false)
    local interval = self.animation.interval or 12
    for i = from + 1, to, (from < to and 1 or -1) do
        method(self.winid, i)
        pause(interval)
    end
    self:set('wrap', wrap)
end

---Resize window
---@param opts
---|{ width: integer, height: integer }
function window:resize(opts)
    if opts.height and self:height() ~= opts.height then
        self:smooth_expand {
            field = 'height',
            to = opts.height,
        }
    end

    if opts.width and self:width() ~= opts.width then
        self:smooth_expand {
            field = 'width',
            to = opts.width,
        }
    end
end

---Try to close window with animation?
function window:try_close()
    local close_animation = self.animation.close
    if close_animation then
        local field = ({
            slid = 'width',
            fold = 'height',
        })[close_animation]

        self:smooth_expand {
            field = field,
            to = 1,
        }
    end

    api.nvim_win_close(self.winid, true)
end

---Set window local highlight group
---@param name string
---@param opts table highlight config
---@param ns integer namespace
function window:set_hl(name, opts, ns)
    api.nvim_set_hl(ns, name, opts)
end

---Open window with animation?
function window:open()
    local win_opts = self.win_opts
    local open_animation = self.animation.open
    if open_animation then
        local field = ({
            slid = 'width',
            fold = 'height',
        })[open_animation]

        local to = win_opts[field]
        win_opts[field] = 1
        self.winid = api.nvim_open_win(self.buffer.bufnr, self.enter, win_opts)
        self:smooth_expand {
            field = field,
            to = to,
        }
    else
        self.winid = api.nvim_open_win(self.buffer.bufnr, self.enter, win_opts)
    end
end

window.__index = window


---@alias WindowOpts
---|{style: string, border: string, focusable: boolean, noautocmd?: boolean, relative: 'mouse'|'cursor'|'editor'|'win', width: integer, height: integer, col: integer, row: integer, zindex?: integer, title?: table | string}


---@class TransWindow
---@field buffer TransBuffer attached buffer object
---@field win_opts table window config [**When open**]
---@field winid integer window handle
---@field enter boolean cursor should [enter] window when open
---@field animation
---|{open: string | boolean, close: string | boolean, interval: integer} Hover Window Animation

-- local win_opt   = {
--     zindex    = zindex,
--     width     = width,
--     height    = height,
--     col       = col,
--     row       = row,
--     border    = border,
--     title     = title,
--     relative  = relative,
-- }

local default_opts = {
    enter    = false,
    winid    = -1,
    ---@type WindowOpts
    win_opts = {
        -- INFO : ensured options
        -- col
        -- row
        -- width
        -- height
        -- relative
        -- zindex
        style     = 'minimal',
        border    = 'rounded',
        focusable = false,
        noautocmd = true,
    },
}

---@class TransWindowOpts
---@field buffer TransBuffer attached buffer object
---@field enter? boolean cursor should [enter] window when open,default: false
---@field win_opts WindowOpts window config [**When open**]
---@field animation? table? Hover Window Animation

---Create new window
---@param opts TransWindowOpts window config
---@return TransWindow
function window.new(opts)
    opts = vim.tbl_deep_extend('keep', opts, default_opts)
    opts.animation = opts.animation or { interval = 12 }

    local win = setmetatable(opts, window)
    ---@cast win TransWindow

    win:open()
    return win
end

---@class Trans
---@field window TransWindow
return window