package server

import (
	"context"
	"database/sql"
	"fmt"
	"log"

	"github.com/juls0730/flux/pkg"
)

var (
	deploymentInsertStmt *sql.Stmt
	containerInsertStmt  *sql.Stmt
	volumeInsertStmt     *sql.Stmt
	updateVolumeStmt     *sql.Stmt
)

type Deployment struct {
	ID         int64            `json:"id"`
	Containers []Container      `json:"containers,omitempty"`
	Proxy      *DeploymentProxy `json:"-"`
	URL        string           `json:"url"`
	Port       uint16           `json:"port"`
}

// Creates a deployment and containers in the database
func CreateDeployment(container Container, port uint16, appUrl string, db *sql.DB) (Deployment, error) {
	var deployment Deployment
	var err error

	if deploymentInsertStmt == nil {
		deploymentInsertStmt, err = db.Prepare("INSERT INTO deployments (url, port) VALUES ($1, $2) RETURNING id, url, port")
		if err != nil {
			log.Printf("Failed to prepare statement: %v\n", err)
			return Deployment{}, err
		}
	}

	err = deploymentInsertStmt.QueryRow(appUrl, port).Scan(&deployment.ID, &deployment.URL, &deployment.Port)
	if err != nil {
		log.Printf("Failed to insert deployment: %v\n", err)
		return Deployment{}, err
	}

	if containerInsertStmt == nil {
		containerInsertStmt, err = db.Prepare("INSERT INTO containers (container_id, deployment_id, head) VALUES ($1, $2, $3) RETURNING id, container_id, deployment_id, head")
		if err != nil {
			log.Printf("Failed to prepare statement: %v\n", err)
			return Deployment{}, err
		}
	}

	var containerIDString string
	err = containerInsertStmt.QueryRow(container.ContainerID[:], deployment.ID, true).Scan(&container.ID, &containerIDString, &container.DeploymentID, &container.Head)
	if err != nil {
		log.Printf("Failed to get container id: %v\n", err)
		return Deployment{}, err
	}
	copy(container.ContainerID[:], containerIDString)

	for i, volume := range container.Volumes {
		if volumeInsertStmt == nil {
			volumeInsertStmt, err = db.Prepare("INSERT INTO volumes (volume_id, container_id) VALUES (?, ?) RETURNING id, volume_id, container_id")
			if err != nil {
				log.Printf("Failed to prepare statement: %v\n", err)
				return Deployment{}, err
			}
		}

		if err := volumeInsertStmt.QueryRow(volume.VolumeID, container.ID).Scan(&container.Volumes[i].ID, &container.Volumes[i].VolumeID, &container.Volumes[i].ContainerID); err != nil {
			log.Printf("Failed to insert volume: %v\n", err)
			return Deployment{}, err
		}
	}

	container.Deployment = &deployment
	deployment.Containers = append(deployment.Containers, container)

	return deployment, nil
}

func (deployment *Deployment) Upgrade(ctx context.Context, projectConfig pkg.ProjectConfig, imageName string, projectPath string) error {
	existingContainers, err := findExistingDockerContainers(ctx, projectConfig.Name)
	if err != nil {
		return fmt.Errorf("Failed to find existing containers: %v", err)
	}

	// Deploy new container before deleting old one
	c, err := CreateDockerContainer(ctx, imageName, projectPath, projectConfig)
	if err != nil || c == nil {
		log.Printf("Failed to create container: %v\n", err)
		return err
	}

	var container Container = *c
	if containerInsertStmt == nil {
		containerInsertStmt, err = Flux.db.Prepare("INSERT INTO containers (container_id, deployment_id, head) VALUES ($1, $2, $3) RETURNING id, container_id, deployment_id, head")
		if err != nil {
			log.Printf("Failed to prepare statement: %v\n", err)
			return err
		}
	}

	var containerIDString string
	err = containerInsertStmt.QueryRow(container.ContainerID[:], deployment.ID, true).Scan(&container.ID, &containerIDString, &container.DeploymentID, &container.Head)
	if err != nil {
		log.Printf("Failed to get container id: %v\n", err)
		return err
	}
	container.Deployment = deployment

	// the space time complexity of this is pretty bad, but it works
	for _, existingContainer := range deployment.Containers {
		if !existingContainer.Head {
			continue
		}

		for _, volume := range existingContainer.Volumes {
			var targetVolume *Volume
			for i, volume := range container.Volumes {
				if volume.VolumeID == volume.VolumeID {
					targetVolume = &container.Volumes[i]
					break
				}
			}

			if updateVolumeStmt == nil {
				updateVolumeStmt, err = Flux.db.Prepare("UPDATE volumes SET container_id = ? WHERE id = ? RETURNING id, volume_id, container_id")
				if err != nil {
					log.Printf("Failed to prepare statement: %v\n", err)
					return err
				}
			}

			err := updateVolumeStmt.QueryRow(container.ID, volume.ID).Scan(&targetVolume.ID, &targetVolume.VolumeID, &targetVolume.ContainerID)
			if err != nil {
				log.Printf("Failed to update volume: %v\n", err)
				return err
			}
		}
	}

	copy(container.ContainerID[:], containerIDString)
	deployment.Containers = append(deployment.Containers, container)

	log.Printf("Starting container %s...\n", container.ContainerID[:12])
	err = container.Start(ctx)
	if err != nil {
		log.Printf("Failed to start container: %v\n", err)
		return err
	}

	if err := container.Wait(ctx, projectConfig.Port); err != nil {
		log.Printf("Failed to wait for container: %v\n", err)
		return err
	}

	if _, err := Flux.db.Exec("UPDATE deployments SET url = ?, port = ? WHERE id = ?", projectConfig.Url, projectConfig.Port, deployment.ID); err != nil {
		log.Printf("Failed to update deployment: %v\n", err)
		return err
	}

	// Create a new proxy that points to the new head, and replace the old one, but ensure that the old one is gracefully shutdown
	oldProxy := deployment.Proxy
	deployment.Proxy, err = NewDeploymentProxy(deployment, &container)
	if err != nil {
		log.Printf("Failed to create deployment proxy: %v\n", err)
		return err
	}

	tx, err := Flux.db.Begin()
	if err != nil {
		log.Printf("Failed to begin transaction: %v\n", err)
		return err
	}

	var containers []Container
	var oldContainers []*Container
	for _, container := range deployment.Containers {
		if existingContainers[string(container.ContainerID[:])] {
			log.Printf("Deleting container from db: %s\n", container.ContainerID[:12])

			_, err = tx.Exec("DELETE FROM containers WHERE id = ?", container.ID)
			oldContainers = append(oldContainers, &container)

			if err != nil {
				tx.Rollback()
				return err
			}

			continue
		}

		containers = append(containers, container)
	}

	if err := tx.Commit(); err != nil {
		log.Printf("Failed to commit transaction: %v\n", err)
		return err
	}

	if oldProxy != nil {
		go oldProxy.GracefulShutdown(oldContainers)
	} else {
		for _, container := range oldContainers {
			err := RemoveDockerContainer(context.Background(), string(container.ContainerID[:]))
			if err != nil {
				log.Printf("Failed to remove container: %v\n", err)
			}
		}
	}

	deployment.Containers = containers

	Flux.proxy.AddDeployment(deployment)

	return nil
}

func (d *Deployment) Remove(ctx context.Context) error {
	for _, container := range d.Containers {
		err := container.Remove(ctx)
		if err != nil {
			log.Printf("Failed to remove container (%s): %v\n", container.ContainerID[:12], err)
			return err
		}
	}

	_, err := Flux.db.Exec("DELETE FROM deployments WHERE id = ?", d.ID)
	if err != nil {
		log.Printf("Failed to delete deployment: %v\n", err)
		return err
	}

	return nil
}

func (d *Deployment) Start(ctx context.Context) error {
	for _, container := range d.Containers {
		err := container.Start(ctx)
		if err != nil {
			log.Printf("Failed to start container: %v\n", err)
			return err
		}
	}

	return nil
}

func (d *Deployment) Stop(ctx context.Context) error {
	for _, container := range d.Containers {
		err := container.Stop(ctx)
		if err != nil {
			log.Printf("Failed to start container: %v\n", err)
			return err
		}
	}

	return nil
}

func (d *Deployment) Status(ctx context.Context) (string, error) {
	var status string
	if d == nil {
		fmt.Printf("Deployment is nil\n")
		return "stopped", nil
	}

	if d.Containers == nil {
		fmt.Printf("Containers are nil\n")
		return "stopped", nil
	}

	for _, container := range d.Containers {
		containerStatus, err := container.Status(ctx)
		if err != nil {
			log.Printf("Failed to get container status: %v\n", err)
			return "", err
		}

		// if not all containers are in the same state
		if status != "" && status != containerStatus {
			return "", fmt.Errorf("Malformed deployment")
		}

		status = containerStatus
	}

	switch status {
	case "running":
		return "running", nil
	case "exited":
		return "stopped", nil
	default:
		return "pending", nil
	}
}