// 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)
	warning := fmt.Sprintf("%s%s : Site config warning : ", Circles["orange"], site.getName())
	// Make sure config file exists
	if exists, _ := fileExists(path); !exists {
		return false, nil
	}
	log.Printf("Loading per-site config %s", path)
	// 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
	if table.Type().String() != "table" { // Make sure 'config' is of type 'table'
		err := fmt.Sprintf("Value returned by config is of type '%s', not 'table'", table.Type().String())
		sendMessage(MatrixMessage{text: warning + err})
		return false, errors.New(err)
	}

	// Parse the config
	config := SiteConfig{}

	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")) // git
	if gitt, ok := L.GetTable(table, lua.LString("git")).(*lua.LTable); ok {
		if _, err := getStringFromTable(L, gitt, "branch", &config.git.branch); err != nil { // git.branch
			sendMessage(MatrixMessage{text: warning + fmt.Sprint(err)})
		}
	} 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, error) {
	sites_dir := configuration.sites_dir
	files, err := os.ReadDir(sites_dir)
	var sites []Site
	if err != nil {
		return sites, errors.New(fmt.Sprintf("Failed to read sites: %s", err))
	}
	for _, file := range files {
		if !file.IsDir() {
			continue
		}
		site, exists, err := getSite(file.Name())
		if err != nil || !exists {
			return sites, errors.New(fmt.Sprintf("Failed to read sites: %s", err))
		}
		sites = append(sites, site)
	}
	return sites, nil
}

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

// Start attempts to start a Lapis server in the given repository.
func (site *Site) Start() error {
	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 errors.New(fmt.Sprintf("Failed to start Lapis server in '%s': %s", site.getName(), err))
	}
	go func() {
		cmd.Wait()
	}()

	return nil
}

// Stop attempts to stop a Lapis server in the given repository.
func (site *Site) Stop() error {
	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 errors.New(fmt.Sprintf("Failed to stop Lapis server in '%s': %s", site.getName(), err))
	}
	go func() {
		cmd.Wait()
	}()
	return nil
}

// Restart attempts to restart the Lapis server in the given repository.
func (site *Site) Restart() error {
	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 errors.New(fmt.Sprintf("Failed to run 'lapis build' in '%s': %s", site.getName(), err))
	}
	log.Printf("[lapis build] %s", out)
	if !strings.Contains(string(out), "HUP") {
		return errors.New(fmt.Sprintf("Failed to restart Lapis server! (Lapis not running?): %s", string(out)))
	}
	return nil
}

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

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