// Package layout defines Skiff's directory and dataset conventions in one
// place. Nothing else in the codebase should hardcode a path.
package layout

import (
	"fmt"
	"path/filepath"
)

const (
	DefaultHealthPort = 8080
	DefaultHealthPath = "/healthz"
	HealthTimeoutSecs = 10
	DefaultJailIface  = "vtnet0"
)

// Config is Skiff's host-wide configuration. Every field has a sane FreeBSD
// default; override via flags on the skiff binary if a host differs.
type Config struct {
	ZFSPool      string // e.g. "zroot"
	BaseDataset  string // template jail root, cloned per app
	ReposDir     string // bare git repos live here
	JailsMount   string // parent mountpoint for per-app datasets
	JailConfDir  string // /etc/jail.conf.d
	NginxConfDir string // nginx include dir regenerated on every deploy
	LocksDir     string // per-app flock files live here, outside any per-app dataset
}

func Default() Config {
	return Config{
		ZFSPool:      "zroot/skiff",
		BaseDataset:  "zroot/skiff/base",
		ReposDir:     "/skiff/repos",
		JailsMount:   "/skiff/apps",
		JailConfDir:  "/etc/jail.conf.d",
		NginxConfDir: "/usr/local/etc/nginx/skiff.d",
		LocksDir:     "/skiff/locks",
	}
}

func (c Config) AppDataset(app string) string {
	return fmt.Sprintf("%s/apps/%s", c.ZFSPool, app)
}

func (c Config) JailRoot(app string) string {
	return filepath.Join(c.JailsMount, app)
}

func (c Config) RepoPath(app string) string {
	return filepath.Join(c.ReposDir, app+".git")
}

// LockPath is the per-app flock file that serializes deploy, config change,
// and rollback against each other. It deliberately lives outside
// AppDataset(app): that dataset gets `zfs rollback`ed on a failed health
// check or a manual rollback, which would discard a lock file living inside
// it along with everything else written since the snapshot.
func (c Config) LockPath(app string) string {
	return filepath.Join(c.LocksDir, app+".lock")
}

func (c Config) JailConfPath(app string) string {
	return filepath.Join(c.JailConfDir, app+".conf")
}

func (c Config) NginxConfPath(app string) string {
	return filepath.Join(c.NginxConfDir, app+".conf")
}

func (c Config) PostReceiveHookPath(app string) string {
	return filepath.Join(c.RepoPath(app), "hooks", "post-receive")
}

// RCScriptPath, RCConfPath, and DMAConfPath are paths inside the jail's own
// chroot, not the host's rc.d/rc.conf/dma.conf.
func (c Config) RCScriptPath(app string) string {
	return filepath.Join(c.JailRoot(app), "usr", "local", "etc", "rc.d", app)
}

func (c Config) RCConfPath(app string) string {
	return filepath.Join(c.JailRoot(app), "etc", "rc.conf")
}

func (c Config) DMAConfPath(app string) string {
	return filepath.Join(c.JailRoot(app), "etc", "dma", "dma.conf")
}

// Everything below is Capistrano-style: each deploy gets its own immutable
// releases/<sha> checkout (built in place, inside the jail's own dataset),
// `current` is a symlink to whichever release is live, and data.db/env are
// persistent siblings that outlive any single release.
func (c Config) AppDir(app string) string {
	return filepath.Join(c.JailRoot(app), "app")
}

func (c Config) ReleasesDir(app string) string {
	return filepath.Join(c.AppDir(app), "releases")
}

func (c Config) ReleaseDir(app, sha string) string {
	return filepath.Join(c.ReleasesDir(app), sha)
}

func (c Config) CurrentRelease(app string) string {
	return filepath.Join(c.AppDir(app), "current")
}

// ReleaseDirInJail is releases/<sha> as seen from inside the jail's own
// chroot, not the host. The `current` symlink must be written with this
// form as its target: it's dereferenced by the jail's rc.d script (which
// execs /app/current/app, per internal/tmpl/rc.d.tmpl's command_args),
// where a host-absolute path like ReleaseDir's resolves relative to the
// jail root instead and never exists.
func (c Config) ReleaseDirInJail(sha string) string {
	return filepath.Join("/app", "releases", sha)
}

func (c Config) MetaPath(app string) string {
	return filepath.Join(c.AppDir(app), "meta.json")
}

func (c Config) EnvPath(app string) string {
	return filepath.Join(c.AppDir(app), "env")
}