--[[--
KOReader plugin adding a "Upload to slenpaste" action to the File Manager long-press menu.

@module koplugin.slenpaste
--]]--

local http = require("socket.http")
local ltn12 = require("ltn12")
local Device = require("device")
local InfoMessage = require("ui/widget/infomessage")
local QRMessage = require("ui/widget/qrmessage")
local RadioButtonWidget = require("ui/widget/radiobuttonwidget")
local ButtonDialog = require("ui/widget/buttondialog")
local Font = require("ui/font")
local TextBoxWidget = require("ui/widget/textboxwidget")
local UIManager = require("ui/uimanager")
local NetworkMgr = require("ui/network/manager")
local WidgetContainer = require("ui/widget/container/widgetcontainer")
local util = require("util")
local _ = require("gettext")
local T = require("ffi/util").template

local SlenPaste = WidgetContainer:extend{
    name = "slenpaste",
    is_doc_only = false,
    upload_url = "https://paste.slendi.dev/",
    settings_key = "slenpaste",
}

SlenPaste.expiry_options = {
    { label = _("5 minutes"), value = "5m" },
    { label = _("1 hour"), value = "1h" },
    { label = _("1 day"), value = "1d" },
    { label = _("7 days"), value = "7d" },
    { label = _("30 days"), value = "30d" },
    { label = _("Expires on first view"), value = "view" },
    { label = _("Never"), value = "0" },
}

function SlenPaste:init()
    self.settings = G_reader_settings:readSetting(self.settings_key, {})
    if not self.ui.document then
        self:registerFileManagerActions()
    end
end

function SlenPaste:registerFileManagerActions()
    local file_manager = self.ui
    if not file_manager or not file_manager.addFileDialogButtons then
        return
    end
    local plugin = self
    file_manager:addFileDialogButtons("slenpaste_upload", function(file, is_file)
        if not is_file then
            return nil
        end
        return {
            {
                text = _("Upload to Slenpaste"),
                callback = function()
                    if file_manager.file_dialog then
                        UIManager:close(file_manager.file_dialog)
                    end
                    plugin:promptExpiryAndUpload(file)
                end,
            },
        }
    end)
end

function SlenPaste:getDefaultExpiry()
    local remembered = self.settings and self.settings.last_expiry
    if remembered then
        return remembered
    end
    return "1d"
end

function SlenPaste:promptExpiryAndUpload(file_path)
    local radio_buttons = {}
    local default_expiry = self:getDefaultExpiry()
    for index, option in ipairs(self.expiry_options) do
        radio_buttons[index] = {
            {
                text = option.label,
                provider = option.value,
                checked = option.value == default_expiry,
            },
        }
    end

    UIManager:show(RadioButtonWidget:new{
        title_text = _("Slenpaste expiry"),
        ok_text = _("Upload"),
        cancel_text = _("Cancel"),
        radio_buttons = radio_buttons,
        callback = function(widget)
            local expiry = widget.provider
            self.settings.last_expiry = expiry
            G_reader_settings:saveSetting(self.settings_key, self.settings)
            NetworkMgr:runWhenConnected(function()
                self:startUpload(file_path, expiry)
            end)
        end,
    })
end

function SlenPaste:startUpload(file_path, expiry)
    local uploading_message = InfoMessage:new{
        text = _("Uploading to slenpaste…"),
    }
    UIManager:show(uploading_message)

    local ok, result = self:performUpload(file_path, expiry)

    UIManager:close(uploading_message)

    if ok then
        self:showSuccessDialog(result)
    else
        self:showError(result)
    end
end

function SlenPaste:performUpload(file_path, expiry)
    local file, err = io.open(file_path, "rb")
    if not file then
        return false, err or _("Unable to open file")
    end

    local filename = file_path:match("([^/]+)$") or "upload"
    filename = filename:gsub('["\r\n]', "_")

    local boundary = "----KOReaderSlenpaste" .. tostring(os.time()) .. tostring(math.random(1000, 9999))
    local CRLF = "\r\n"

    local prefix = table.concat({
        "--", boundary, CRLF,
        "Content-Disposition: form-data; name=\"expiry\"", CRLF,
        CRLF,
        tostring(expiry), CRLF,
        "--", boundary, CRLF,
        string.format("Content-Disposition: form-data; name=\"file\"; filename=\"%s\"", filename), CRLF,
        "Content-Type: application/octet-stream", CRLF,
        CRLF,
    })
    local suffix = CRLF .. "--" .. boundary .. "--" .. CRLF

    local file_size = file:seek("end")
    file:seek("set", 0)

    local response_body = {}
    local file_closed = false
    local function close_file()
        if not file_closed then
            file_closed = true
            file:close()
        end
    end
    local function file_source()
        if file_closed then
            return nil
        end
        local chunk = file:read(8192)
        if chunk then
            return chunk
        end
        close_file()
        return nil
    end

    local request_body = ltn12.source.cat(
        ltn12.source.string(prefix),
        file_source,
        ltn12.source.string(suffix)
    )

    local ok, status_code, headers, status_line = http.request{
        url = self.upload_url,
        method = "POST",
        headers = {
            ["Content-Type"] = "multipart/form-data; boundary=" .. boundary,
            ["Content-Length"] = tostring(#prefix + file_size + #suffix),
        },
        source = request_body,
        sink = ltn12.sink.table(response_body),
    }

    close_file()

    if not ok then
        return false, status_code or _("HTTP request failed")
    end

    local code = tonumber(status_code) or 0
    if code < 200 or code >= 300 then
        local body_text = util.trim(table.concat(response_body))
        if body_text ~= "" then
            return false, string.format("%s (%s)", status_line or "HTTP error", body_text)
        end
        return false, status_line or string.format("HTTP status %d", code)
    end

    local url = util.trim(table.concat(response_body))
    if url == "" then
        return false, _("Empty response from server")
    end

    return true, url
end

function SlenPaste:showSuccessDialog(url)
    local buttons
    local dialog
    buttons = {
        {
            {
                text = _("Copy link"),
                enabled = Device:hasClipboard(),
                callback = function()
                    Device.input.setClipboardText(url)
                    UIManager:show(InfoMessage:new{
                        text = _("Link copied to clipboard"),
                    })
                end,
            },
            {
                text = _("Show QR code"),
                callback = function()
                    UIManager:show(QRMessage:new{
                        text = url,
                        width = Device.screen:getWidth(),
                        height = Device.screen:getHeight(),
                    })
                end,
            },
        },
        {
            {
                text = _("Close"),
                callback = function()
                    UIManager:close(dialog)
                end,
            },
        },
    }

    dialog = ButtonDialog:new{
        title = _("Slenpaste upload complete"),
        buttons = buttons,
    }

    dialog:addWidget(TextBoxWidget:new{
        text = url,
        width = dialog:getAddedWidgetAvailableWidth(),
        face = Font:getFace("infofont"),
    })

    UIManager:show(dialog)
end

function SlenPaste:showError(message)
    UIManager:show(InfoMessage:new{
        text = T(_("Upload failed:\n%s"), message),
    })
end

return SlenPaste