--[[
    KOReader Fetch Plugin
    
    Fetches files from a remote server endpoint and saves them to a configured directory.
    
    Installation:
    1. Copy this file to: koreader/plugins/fetch.koplugin/main.lua
    2. Create config file at: koreader/plugins/fetch.koplugin/config.lua with:
       return {
           server_url = "http://example.com/get",
           auth_token = "your-secret-token-here-change-me"
       }
    3. Restart KOReader
]]

local DataStorage = require("datastorage")
local Dispatcher = require("dispatcher")
local FFIUtil = require("ffi/util")
local InfoMessage = require("ui/widget/infomessage")
local PathChooser = require("ui/widget/pathchooser")
local UIManager = require("ui/uimanager")
local WidgetContainer = require("ui/widget/container/widgetcontainer")
local http = require("socket.http")
local ltn12 = require("ltn12")
local logger = require("logger")
local _ = require("gettext")
local T = FFIUtil.template
local ffi = require("ffi")
local C = ffi.C

-- Load configuration
local function loadConfig()
    local config_path = FFIUtil.joinPath(
        FFIUtil.joinPath(DataStorage:getDataDir(), "plugins"),
        "fetch.koplugin/config.lua"
    )
    
    local ok, config = pcall(dofile, config_path)
    if ok and config then
        return config
    else
        logger.warn("Fetch plugin: Could not load config file, using defaults")
        return {
            server_url = "http://192.168.1.100:8000/get",
            auth_token = "your-secret-token-here"
        }
    end
end

local Fetch = WidgetContainer:extend{
    name = "fetch",
    is_doc_only = false,
}

function Fetch:init()
    -- Load server configuration
    self.config = loadConfig()
    
    -- Load or set default home directory
    self.settings = G_reader_settings:readSetting("fetch_plugin") or {}
    self.home_directory = self.settings.home_directory or "/mnt/onboard/fetched"
    
    -- Add menu items
    self.ui.menu:registerToMainMenu(self)
    
    logger.info("Fetch plugin initialized")
end

function Fetch:addToMainMenu(menu_items)
    menu_items.fetch = {
        text = _("Fetch Files"),
        sub_item_table = {
            {
                text = _("Fetch Now"),
                callback = function()
                    self:fetchFiles()
                end,
            },
            {
                text = _("Configure Home Directory"),
                keep_menu_open = true,
                callback = function()
                    self:showDirectoryDialog()
                end,
            },
            {
                text = _("View Settings"),
                keep_menu_open = true,
                callback = function()
                    self:showSettings()
                end,
            },
        },
    }
end

function Fetch:showSettings()
    local text = T(_(
        "Server URL: %1\n" ..
        "Auth Token: %2\n" ..
        "Home Directory: %3\n\n" ..
        "To change server settings, edit:\n" ..
        "koreader/plugins/fetch.koplugin/config.lua"
    ),
        self.config.server_url,
        string.sub(self.config.auth_token, 1, 10) .. "...",
        self.home_directory
    )
    
    UIManager:show(InfoMessage:new{
        text = text,
        timeout = 5,
    })
end

function Fetch:showDirectoryDialog()
    local path_chooser = PathChooser:new{
        title = _("Choose Home Directory"),
        path = self.home_directory,
        show_files = false,
        onConfirm = function(new_dir)
            self.home_directory = new_dir
            self.settings.home_directory = new_dir
            G_reader_settings:saveSetting("fetch_plugin", self.settings)
            
            UIManager:show(InfoMessage:new{
                text = T(_("Home directory set to:\n%1"), new_dir),
                timeout = 2,
            })
        end,
    }
    UIManager:show(path_chooser)
end

function Fetch:fetchFiles()
    logger.info("Fetch: Starting file fetch from " .. self.config.server_url)
    
    UIManager:show(InfoMessage:new{
        text = _("Fetching files from server..."),
        timeout = 1,
    })
    
    -- Ensure home directory exists
    local lfs = require("libs/libkoreader-lfs")
    local attributes = lfs.attributes(self.home_directory)
    if not attributes or attributes.mode ~= "directory" then
        UIManager:show(InfoMessage:new{
            text = T(_("Home directory does not exist:\n%1"), self.home_directory),
            timeout = 3,
        })
        return
    end
    
    -- Generate temporary file path for downloaded zip
    local temp_zip = FFIUtil.joinPath(
        DataStorage:getDataDir(),
        "fetch_temp_" .. os.time() .. ".zip"
    )
    
    -- Download file using socket.http
    local response_body = {}
    local request_body = ""
    
    local result, status_code, headers = http.request{
        url = self.config.server_url,
        method = "POST",
        headers = {
            ["Authorization"] = "Bearer " .. self.config.auth_token,
            ["Content-Length"] = "0",
        },
        sink = ltn12.sink.table(response_body)
    }
    
    logger.info("Fetch: HTTP result=" .. tostring(result) .. ", status=" .. tostring(status_code))
    
    if not result or status_code ~= 200 then
        local error_msg = _("Failed to fetch files from server")
        if status_code == 401 then
            error_msg = _("Authentication failed. Check your token.")
        elseif status_code == 404 then
            error_msg = _("No files available on server")
        elseif not result then
            error_msg = _("Could not connect to server")
        end
        
        UIManager:show(InfoMessage:new{
            text = error_msg,
            timeout = 3,
        })
        return
    end
    
    -- Concatenate response body
    local zip_data = table.concat(response_body)
    
    if #zip_data == 0 then
        UIManager:show(InfoMessage:new{
            text = _("No files received from server"),
            timeout = 3,
        })
        return
    end
    
    logger.info("Fetch: Downloaded " .. #zip_data .. " bytes")
    
    -- Write zip data to temp file
    local file = io.open(temp_zip, "wb")
    if not file then
        UIManager:show(InfoMessage:new{
            text = _("Failed to save downloaded file"),
            timeout = 3,
        })
        return
    end
    file:write(zip_data)
    file:close()
    
    -- Extract zip file
    local extract_success, file_count = self:extractZip(temp_zip, self.home_directory)
    
    -- Cleanup temp file
    self:cleanup(temp_zip)
    
    if extract_success then
        UIManager:show(InfoMessage:new{
            text = T(_("Successfully fetched %1 file(s) to:\n%2"), file_count, self.home_directory),
            timeout = 3,
        })
        logger.info("Fetch: Successfully extracted " .. file_count .. " files")
    else
        UIManager:show(InfoMessage:new{
            text = _("Failed to extract downloaded files"),
            timeout = 3,
        })
    end
end

function Fetch:extractZip(zip_path, destination)
    logger.info("Fetch: Extracting zip to " .. destination)
    
    -- Use system unzip command
    local unzip_cmd = string.format(
        'unzip -o "%s" -d "%s" 2>&1',
        zip_path,
        destination
    )
    
    logger.dbg("Fetch: Running unzip command")
    local handle = io.popen(unzip_cmd)
    if not handle then
        logger.err("Fetch: Failed to execute unzip command")
        return false, 0
    end
    
    local output = handle:read("*a")
    local success = handle:close()
    
    logger.info("Fetch: Unzip output: " .. output)
    
    if not success then
        logger.err("Fetch: Failed to extract zip file")
        return false, 0
    end
    
    -- Count extracted files from output
    local file_count = 0
    for line in output:gmatch("[^\r\n]+") do
        if line:match("inflating:") or line:match("extracting:") then
            file_count = file_count + 1
        end
    end
    
    -- If count is 0, try counting files in directory
    if file_count == 0 then
        local lfs = require("libs/libkoreader-lfs")
        for file in lfs.dir(destination) do
            if file ~= "." and file ~= ".." then
                local attr = lfs.attributes(FFIUtil.joinPath(destination, file))
                if attr and attr.mode == "file" then
                    file_count = file_count + 1
                end
            end
        end
    end
    
    return true, file_count
end

function Fetch:cleanup(file_path)
    if file_path then
        os.remove(file_path)
        logger.dbg("Fetch: Cleaned up temporary file")
    end
end

function Fetch:onDispatcherRegisterActions()
    Dispatcher:registerAction("fetch_files", {
        category = "none",
        event = "FetchFiles",
        title = _("Fetch files from server"),
        general = true,
    })
end

function Fetch:onFetchFiles()
    self:fetchFiles()
end

return Fetch