package config

import (
	"fmt"
	"os"
	"regexp"

	"github.com/dokku/dokku/plugins/common"
)

// Get retrieves a value from a config. If appName is empty the global config is used.
func Get(appName string, key string) (value string, ok bool) {
	env, err := loadAppOrGlobalEnv(appName)
	if err != nil {
		return "", false
	}
	if err = validateKey(key); err != nil {
		return "", false
	}
	return env.Get(key)
}

// GetWithDefault gets a value from a config. If appName is empty the global config is used. If the appName or key do not exist defaultValue is returned.
func GetWithDefault(appName string, key string, defaultValue string) (value string) {
	value, ok := Get(appName, key)
	if !ok {
		return defaultValue
	}
	return value
}

// SetMany variables in the environment. If appName is empty the global config is used. If restart is true the app is restarted.
func SetMany(appName string, entries map[string]string, replace bool, restart bool) (err error) {
	global := appName == "" || appName == "--global"
	env, err := loadAppOrGlobalEnv(appName)
	if err != nil {
		return
	}
	keys := make([]string, 0, len(entries))
	for k := range entries {
		if err = validateKey(k); err != nil {
			return
		}
	}

	if replace {
		env.Clear()
	}
	for k, v := range entries {
		env.Set(k, v)
		keys = append(keys, k)
	}
	if len(entries) != 0 {
		common.LogInfo1Quiet("Setting config vars")
		if os.Getenv("DOKKU_QUIET_OUTPUT") == "" {
			fmt.Println(prettyPrintEnvEntries("       ", entries))
		}
		env.Write()
		common.SetPermissions(common.SetPermissionInput{
			Filename: env.Filename(),
			Mode:     os.FileMode(0600),
		})
		triggerUpdate(appName, "set", keys)
	}
	if !global && restart && shouldRestart(appName) {
		triggerRestart(appName)
	}
	return
}

// UnsetMany a value in a config. If appName is empty the global config is used. If restart is true the app is restarted.
func UnsetMany(appName string, keys []string, restart bool) (err error) {
	global := appName == "" || appName == "--global"
	env, err := loadAppOrGlobalEnv(appName)
	if err != nil {
		return
	}
	var changed = false
	for _, k := range keys {
		if err = validateKey(k); err != nil {
			return
		}
	}
	for _, k := range keys {
		if _, hasKey := env.Map()[k]; hasKey {
			common.LogInfo1Quiet(fmt.Sprintf("Unsetting %s", k))
			env.Unset(k)
			changed = true
		} else {
			common.LogInfo1Quiet(fmt.Sprintf("Skipping %s, it is not set in the environment", k))
		}
	}
	if changed {
		env.Write()
		common.SetPermissions(common.SetPermissionInput{
			Filename: env.Filename(),
			Mode:     os.FileMode(0600),
		})
		triggerUpdate(appName, "unset", keys)
	}
	if !global && restart && shouldRestart(appName) {
		triggerRestart(appName)
	}
	return
}

// UnsetAll removes all config keys
func UnsetAll(appName string, restart bool) (err error) {
	global := appName == "" || appName == "--global"
	env, err := loadAppOrGlobalEnv(appName)
	if err != nil {
		return
	}
	var changed = false
	for k := range env.Map() {
		common.LogInfo1Quiet(fmt.Sprintf("Unsetting %s", k))
		env.Unset(k)
		changed = true
	}
	if changed {
		env.Write()
		common.SetPermissions(common.SetPermissionInput{
			Filename: env.Filename(),
			Mode:     os.FileMode(0600),
		})
		triggerUpdate(appName, "clear", []string{})
	}
	if !global && restart && shouldRestart(appName) {
		triggerRestart(appName)
	}
	return
}

func shouldRestart(appName string) bool {
	results, _ := common.CallPlugnTrigger(common.PlugnTriggerInput{
		Trigger: "ps-get-property",
		Args:    []string{appName, "restore"},
	})
	return results.StdoutContents() != "false"
}

func triggerRestart(appName string) {
	if !common.IsDeployed(appName) {
		return
	}

	common.LogInfo1(fmt.Sprintf("Restarting app %s", appName))
	_, err := common.CallPlugnTrigger(common.PlugnTriggerInput{
		Trigger:     "release-and-deploy",
		Args:        []string{appName, "", "config-redeploy"},
		StreamStdio: true,
	})
	if err != nil {
		common.LogWarn(fmt.Sprintf("Failure while restarting app: %s", err))
	}
}

func triggerUpdate(appName string, operation string, args []string) {
	args = append([]string{appName, operation}, args...)
	_, err := common.CallPlugnTrigger(common.PlugnTriggerInput{
		Trigger:     "post-config-update",
		Args:        args,
		StreamStdio: true,
	})
	if err != nil {
		common.LogWarn(fmt.Sprintf("Failure while triggering post-config-update: %s", err))
	}
}

// getEnvironment for the given app (global config if appName is empty). Merge with global environment if merged is true.
func getEnvironment(appName string, merged bool) (env *Env) {
	var err error
	if appName != "" && merged {
		env, err = LoadMergedAppEnv(appName)
	} else {
		env, err = loadAppOrGlobalEnv(appName)
	}

	if err != nil {
		common.LogFailWithError(err)
	}

	return env
}

func getAppNameOrGlobal(appName string, global bool) (string, error) {
	if global {
		return appName, nil
	}

	if err := common.VerifyAppName(appName); err != nil {
		return appName, err
	}

	return appName, nil
}

func loadAppOrGlobalEnv(appName string) (env *Env, err error) {
	if appName == "" || appName == "--global" {
		return LoadGlobalEnv()
	}
	return LoadAppEnv(appName)
}

func validateKey(key string) error {
	r, _ := regexp.Compile("^[a-zA-Z_][a-zA-Z0-9_]*$")
	if !r.MatchString(key) {
		return fmt.Errorf("Invalid key name: '%s'", key)
	}
	return nil
}