// package main is the main package for the LapisDeploy program
package main

import (
	"errors"
	"fmt"
	"log"
	"os"
	"os/exec"
	"strings"
	"syscall"

	"github.com/gogs/git-module"
	lua "github.com/yuin/gopher-lua"
)

// Site contains information and methods used for management of a Lapis site.
type Site struct {
	name   string
	config SiteConfig
}

// SiteConfig contains parsed data from a site's configuration file.
type SiteConfig struct {
	port int64
	name string
	git  struct {
		branch string
	}
}

// getSite gets a specific site and returns a Site struct and a bool indicating whether a site was found.
func getSite(name string) (Site, bool, error) {
	site_path := configuration.sites_dir + "/" + name
	exists, err := fileExists(site_path)
	if err != nil {
		return Site{}, false, errors.New(fmt.Sprintf("Failed to get site '%s'", name))
	}
	if exists {
		site := Site{name: name}
		site.getConfig() // Get per-site config
		return site, true, nil
	} else {
		return Site{}, false, nil
	}
}

// getConfig parses a site's configuration file.
func (site *Site) getConfig() (bool, error) {
	path := fmt.Sprintf("%s/%s/deploy_config.lua", configuration.sites_dir, site.name)
	// Make sure config file exists
	if exists, _ := fileExists(path); !exists {
		return false, nil
	}
	// Lua state setup
	L := lua.NewState()
	defer L.Close()

	L.DoFile(path)     // Load the config
	table := L.Get(-1) // Get the table returned by the config file

	// Parse the config
	config := SiteConfig{}
	log.Printf("Loading per-site config %s", path)

	warning := fmt.Sprintf("%s%s : Site config warning : ", Circles["orange"], site.getName())

	if _, err := getStringFromTable(L, table, "name", &config.name); err != nil { // Name
		sendMessage(MatrixMessage{text: warning + fmt.Sprint(err)})
	}
	if _, err := getIntFromTable(L, table, "port", &config.port); err != nil { // Port
		sendMessage(MatrixMessage{text: warning + fmt.Sprint(err)})
	}
	raw_gitt := L.GetTable(table, lua.LString("git")) // Attempt to get 'git' table
	if gitt, ok := raw_gitt.(*lua.LTable); ok {
		getStringFromTable(L, gitt, "branch", &config.git.branch)
	} else if _, ok := raw_gitt.(*lua.LNilType); !ok { // If 'git' is neither a table or nil (undefined),
		sendMessage(MatrixMessage{text: warning + "'git' is neither a table or nil!"})
	}
	site.config = config

	return true, nil
}

// getName gets a website's configured name (falls back to technical name if one isn't configured).
func (site *Site) getName() string {
	if site.config.name == "" {
		return site.name
	} else {
		return site.config.name
	}
}

// getAllSites gets every site installed.
func getAllSites() ([]Site, DeployError) {
	sites_dir := configuration.sites_dir
	files, err := os.ReadDir(sites_dir)
	var sites []Site
	if err != nil {
		return sites, newDeployError(1, "startAllSites",
			"Failed to read sites", fmt.Sprint(err))
	}
	for _, file := range files {
		if !file.IsDir() {
			continue
		}
		site, exists, err := getSite(file.Name())
		if err != nil || !exists {
			return sites, newDeployError(1, "getAllSites", "Failed to read sites", fmt.Sprint(err))
		}
		sites = append(sites, site)
	}
	return sites, DeployError{}
}

// startAllSites attempts to start every site
func startAllSites() DeployError {
	sites, err := getAllSites()
	if err.code != 0 {
		return err
	}
	for _, site := range sites {
		err = site.Start()
		if err.code != 0 {
			return err
		}
	}
	return DeployError{}
}

// Start attempts to start a Lapis server in the given repository.
func (site *Site) Start() DeployError {
	log.Printf("Starting Lapis server in %s...", site.getName())

	old_cwd, _ := os.Getwd()
	defer syscall.Chdir(old_cwd)
	syscall.Chdir(configuration.sites_dir + "/" + site.name)

	cmd := exec.Command("lapis", "serve")
	if err := cmd.Start(); err != nil {
		return newDeployError(1, "startSite",
			fmt.Sprintf("Failed to start Lapis server in '%s'", site.getName()), "")
	}
	go func() {
		cmd.Wait()
	}()

	return DeployError{}
}

// Stop attempts to stop a Lapis server in the given repository.
func (site *Site) Stop() DeployError {
	log.Printf("Stopping Lapis server %s...", site.getName())

	old_cwd, _ := os.Getwd()
	defer syscall.Chdir(old_cwd)
	syscall.Chdir(configuration.sites_dir + "/" + site.name)

	cmd := exec.Command("lapis", "term")
	if err := cmd.Start(); err != nil {
		return newDeployError(1, "stopSite",
			fmt.Sprintf("Failed to stop Lapis server in '%s'", site.getName()), "")
	}
	go func() {
		cmd.Wait()
	}()
	return DeployError{}
}

// Restart attempts to restart the Lapis server in the given repository.
func (site *Site) Restart() DeployError {
	log.Printf("Restarting Lapis server in %s...", site.getName())

	old_cwd, _ := os.Getwd()
	defer syscall.Chdir(old_cwd)
	syscall.Chdir(configuration.sites_dir + "/" + site.name)

	out, err := exec.Command("lapis", "build").CombinedOutput()
	if err != nil {
		return newDeployError(1, "restartSite",
			fmt.Sprintf("Failed to run 'lapis build' in '%s'", site.getName()), string(out))
	}
	log.Printf("[lapis build] %s", out)
	if !strings.Contains(string(out), "HUP") {
		return newDeployError(1, "restartSite",
			"Failed to restart Lapis server! (Lapis not running?)", string(out))
	}
	return DeployError{}
}

// Update attempts to pull or clone a repository using the given name and url
func (site *Site) Update() DeployError {
	log.Printf("Pulling down repository %s...", site.getName())
	repo, err := git.Open(configuration.sites_dir + "/" + site.name)
	if err != nil {
		return newDeployError(1, "updateSite",
			fmt.Sprintf("Failed to open git repository '%s'", site.name), fmt.Sprint(err))
	}
	if err = repo.Pull(); err != nil {
		return newDeployError(1, "updateSite",
			fmt.Sprintf("Failed to pull down git repository '%s'", site.getName()), fmt.Sprint(err))
	}
	return DeployError{}
}

// CloneSite will clone a site and put it in the configured 'sites_dir'
func CloneSite(url string, name string) DeployError {
	log.Printf("Cloning repository %s...", name)
	if err := git.Clone(url, configuration.sites_dir+"/"+name); err != nil {
		return newDeployError(1, "cloneSite",
			fmt.Sprintf("Failed to pull down repository '%s'", name), fmt.Sprint(err))
	}
	return DeployError{}
}