package tasks

import (
	"database/sql"
	"encoding/json"
	"errors"
	"fmt"
	"io/ioutil"
	"os"
	"os/exec"
	"strconv"

	"github.com/ansible-semaphore/semaphore/database"
	"github.com/ansible-semaphore/semaphore/models"
	"github.com/ansible-semaphore/semaphore/util"
)

type task struct {
	task        models.Task
	template    models.Template
	sshKey      models.AccessKey
	inventory   models.Inventory
	repository  models.Repository
	environment models.Environment
	users       []int
	projectID   int
}

func (t *task) fail() {
	t.task.Status = "error"
	if _, err := database.Mysql.Exec("update task set status='error' where id=?", t.task.ID); err != nil {
		panic(err)
	}
}

func (t *task) run() {
	pool.running = t

	defer func() {
		fmt.Println("Stopped running tasks")
		pool.running = nil

		if _, err := database.Mysql.Exec("update task set end=NOW() where id=?", t.task.ID); err != nil {
			fmt.Println("Failed to update task end time")
			t.log("Fatal error with database!")
			panic(err)
		}

		objType := "task"
		desc := "Task ID " + strconv.Itoa(t.task.ID) + " finished"
		if err := (models.Event{
			ProjectID:   &t.projectID,
			ObjectType:  &objType,
			ObjectID:    &t.task.ID,
			Description: &desc,
		}.Insert()); err != nil {
			t.log("Fatal error inserting an event")
			panic(err)
		}
	}()

	if _, err := database.Mysql.Exec("update task set status='running', start=NOW() where id=?", t.task.ID); err != nil {
		fmt.Println("Failed to update task start time")
		t.log("Fatal error with database!")
		panic(err)
	}

	objType := "task"
	desc := "Task ID " + strconv.Itoa(t.task.ID) + " is running"
	if err := (models.Event{
		ProjectID:   &t.projectID,
		ObjectType:  &objType,
		ObjectID:    &t.task.ID,
		Description: &desc,
	}.Insert()); err != nil {
		t.log("Fatal error inserting an event")
		panic(err)
	}

	t.log("Started: " + strconv.Itoa(t.task.ID) + "\n")

	if err := t.populateDetails(); err != nil {
		t.log("Error: " + err.Error())
		t.fail()
		return
	}

	if err := t.installKey(t.repository.SshKey); err != nil {
		t.log("Failed installing ssh key for repository access: " + err.Error())
		t.fail()
		return
	}

	if err := t.updateRepository(); err != nil {
		t.log("Failed updating repository: " + err.Error())
		t.fail()
		return
	}

	if err := t.installInventory(); err != nil {
		t.log("Failed to install inventory: " + err.Error())
		t.fail()
		return
	}

	// todo: write environment

	if err := t.runPlaybook(); err != nil {
		t.log("Running playbook failed: " + err.Error())
		t.fail()
		return
	}

	t.task.Status = "success"
	if _, err := database.Mysql.Exec("update task set status='success' where id=?", t.task.ID); err != nil {
		panic(err)
	}
}

func (t *task) fetch(errMsg string, ptr interface{}, query string, args ...interface{}) error {
	err := database.Mysql.SelectOne(ptr, query, args...)
	if err == sql.ErrNoRows {
		t.log(errMsg)
		return err
	}

	if err != nil {
		t.fail()
		panic(err)
	}

	return nil
}

func (t *task) populateDetails() error {
	// get template
	if err := t.fetch("Template not found!", &t.template, "select * from project__template where id=?", t.task.TemplateID); err != nil {
		return err
	}

	// get project users
	var users []struct {
		ID int `db:"id"`
	}
	if _, err := database.Mysql.Select(&users, "select user_id as id from project__user where project_id=?", t.template.ProjectID); err != nil {
		return err
	}

	t.users = []int{}
	for _, user := range users {
		t.users = append(t.users, user.ID)
	}

	// get access key
	if err := t.fetch("Template Access Key not found!", &t.sshKey, "select * from access_key where id=?", t.template.SshKeyID); err != nil {
		return err
	}

	if t.sshKey.Type != "ssh" {
		t.log("Non ssh-type keys are currently not supported: " + t.sshKey.Type)
		return errors.New("Unsupported SSH Key")
	}

	// get inventory
	if err := t.fetch("Template Inventory not found!", &t.inventory, "select * from project__inventory where id=?", t.template.InventoryID); err != nil {
		return err
	}

	// get inventory services key
	if t.inventory.KeyID != nil {
		if err := t.fetch("Inventory AccessKey not found!", &t.inventory.Key, "select * from access_key where id=?", *t.inventory.KeyID); err != nil {
			return err
		}
	}

	// get inventory ssh key
	if t.inventory.SshKeyID != nil {
		if err := t.fetch("Inventory Ssh Key not found!", &t.inventory.SshKey, "select * from access_key where id=?", *t.inventory.SshKeyID); err != nil {
			return err
		}
	}

	// get repository
	if err := t.fetch("Repository not found!", &t.repository, "select * from project__repository where id=?", t.template.RepositoryID); err != nil {
		return err
	}

	// get repository access key
	if err := t.fetch("Repository Access Key not found!", &t.repository.SshKey, "select * from access_key where id=?", t.repository.SshKeyID); err != nil {
		return err
	}
	if t.repository.SshKey.Type != "ssh" {
		t.log("Repository Access Key is not 'SSH': " + t.repository.SshKey.Type)
		return errors.New("Unsupported SSH Key")
	}

	// get environment
	if len(t.task.Environment) == 0 && t.template.EnvironmentID != nil {
		err := t.fetch("Environment not found", &t.environment, "select * from project__environment where id=?", *t.template.EnvironmentID)
		if err != nil {
			return err
		}
	} else if len(t.task.Environment) > 0 {
		t.environment.JSON = t.task.Environment
	}

	return nil
}

func (t *task) installKey(key models.AccessKey) error {
	t.log("access key " + key.Name + " installed")
	err := ioutil.WriteFile(key.GetPath(), []byte(*key.Secret), 0600)

	return err
}

func (t *task) updateRepository() error {
	repoName := "repository_" + strconv.Itoa(t.repository.ID)
	_, err := os.Stat(util.Config.TmpPath + "/" + repoName)

	cmd := exec.Command("git")
	cmd.Dir = util.Config.TmpPath + "/" + repoName
	cmd.Env = []string{
		"HOME=" + util.Config.TmpPath,
		"PWD=" + util.Config.TmpPath,
		"GIT_SSH_COMMAND=ssh -o StrictHostKeyChecking=no -i " + t.repository.SshKey.GetPath(),
		// "GIT_FLUSH=1",
	}

	if err != nil && os.IsNotExist(err) {
		t.log("Cloning repository")
		cmd.Args = append(cmd.Args, "clone", t.repository.GitUrl, repoName)
	} else if err != nil {
		return err
	} else {
		t.log("Updating repository")
		cmd.Args = append(cmd.Args, "pull", "origin", "master")
	}

	t.logCmd(cmd)
	return cmd.Run()
}

func (t *task) runPlaybook() error {
	playbookName := t.task.Playbook
	if len(playbookName) == 0 {
		playbookName = t.template.Playbook
	}

	args := []string{
		"-i", util.Config.TmpPath + "/inventory_" + strconv.Itoa(t.task.ID),
	}

	if t.inventory.SshKeyID != nil {
		args = append(args, "--private-key="+t.inventory.SshKey.GetPath())
	}

	if t.task.Debug {
		args = append(args, "-vvvv")
	}

	if len(t.environment.JSON) > 0 {
		args = append(args, "--extra-vars", t.environment.JSON)
	}

	var extraArgs []string
	if t.template.Arguments != nil {
		err := json.Unmarshal([]byte(*t.template.Arguments), &extraArgs)
		if err != nil {
			t.log("Could not unmarshal arguments to []string")
			return err
		}
	}

	if t.template.OverrideArguments {
		args = extraArgs
	} else {
		args = append(args, extraArgs...)
		args = append(args, playbookName)
	}

	cmd := exec.Command("ansible-playbook", args...)
	cmd.Dir = util.Config.TmpPath + "/repository_" + strconv.Itoa(t.repository.ID)
	cmd.Env = []string{
		"HOME=" + util.Config.TmpPath,
		"PWD=" + cmd.Dir,
		"PYTHONUNBUFFERED=1",
		// "GIT_FLUSH=1",
	}

	t.logCmd(cmd)
	return cmd.Run()
}