package server

import (
	"bytes"
	"context"
	"encoding/json"
	"log"
	"os"
	"strconv"

	"github.com/cncd/logging"
	"github.com/cncd/pipeline/pipeline/rpc"
	"github.com/cncd/pubsub"
	"github.com/cncd/queue"
	"github.com/gin-gonic/gin"

	"github.com/drone/drone/model"
	"github.com/drone/drone/remote"
	"github.com/drone/drone/store"
)

// This file is a complete disaster because I'm trying to wedge in some
// experimental code. Please pardon our appearance during renovations.

var config = struct {
	pubsub pubsub.Publisher
	queue  queue.Queue
	logger logging.Log
	secret string
	host   string
}{
	pubsub.New(),
	queue.New(),
	logging.New(),
	os.Getenv("DRONE_SECRET"),
	os.Getenv("DRONE_HOST"),
}

func init() {
	config.pubsub.Create(context.Background(), "topic/events")
}

// func SetupRPC() gin.HandlerFunc {
// 	return func(c *gin.Context) {
// 		c.Next()
// 	}
// }

func RPCHandler(c *gin.Context) {

	if secret := c.Request.Header.Get("Authorization"); secret != "Bearer "+config.secret {
		log.Printf("Unable to connect agent. Invalid authorization token %q does not match %q", secret, config.secret)
		c.String(401, "Unable to connect agent. Invalid authorization token")
		return
	}
	peer := RPC{
		remote: remote.FromContext(c),
		store:  store.FromContext(c),
		queue:  config.queue,
		pubsub: config.pubsub,
		logger: config.logger,
		host:   config.host,
	}
	rpc.NewServer(&peer).ServeHTTP(c.Writer, c.Request)
}

type RPC struct {
	remote remote.Remote
	queue  queue.Queue
	pubsub pubsub.Publisher
	logger logging.Log
	store  store.Store
	host   string
}

// Next implements the rpc.Next function
func (s *RPC) Next(c context.Context, filter rpc.Filter) (*rpc.Pipeline, error) {
	fn := func(task *queue.Task) bool {
		for k, v := range filter.Labels {
			if task.Labels[k] != v {
				return false
			}
		}
		return true
	}
	task, err := s.queue.Poll(c, fn)
	if err != nil {
		return nil, err
	} else if task == nil {
		return nil, nil
	}
	pipeline := new(rpc.Pipeline)
	err = json.Unmarshal(task.Data, pipeline)
	return pipeline, err
}

// Wait implements the rpc.Wait function
func (s *RPC) Wait(c context.Context, id string) error {
	return s.queue.Wait(c, id)
}

// Extend implements the rpc.Extend function
func (s *RPC) Extend(c context.Context, id string) error {
	return s.queue.Extend(c, id)
}

// Update implements the rpc.Update function
func (s *RPC) Update(c context.Context, id string, state rpc.State) error {
	procID, err := strconv.ParseInt(id, 10, 64)
	if err != nil {
		return err
	}

	pproc, err := s.store.ProcLoad(procID)
	if err != nil {
		log.Printf("error: rpc.update: cannot find pproc with id %d: %s", procID, err)
		return err
	}

	build, err := s.store.GetBuild(pproc.BuildID)
	if err != nil {
		log.Printf("error: cannot find build with id %d: %s", pproc.BuildID, err)
		return err
	}

	proc, err := s.store.ProcChild(build, pproc.PID, state.Proc)
	if err != nil {
		log.Printf("error: cannot find proc with name %s: %s", state.Proc, err)
		return err
	}

	repo, err := s.store.GetRepo(build.RepoID)
	if err != nil {
		log.Printf("error: cannot find repo with id %d: %s", build.RepoID, err)
		return err
	}

	if state.Exited {
		proc.Stopped = state.Finished
		proc.ExitCode = state.ExitCode
		proc.Error = state.Error
		proc.State = model.StatusSuccess
		if state.ExitCode != 0 || state.Error != "" {
			proc.State = model.StatusFailure
		}
	} else {
		proc.Started = state.Started
		proc.State = model.StatusRunning
	}

	if err := s.store.ProcUpdate(proc); err != nil {
		log.Printf("error: rpc.update: cannot update proc: %s", err)
	}

	build.Procs, _ = s.store.ProcList(build)
	message := pubsub.Message{
		Labels: map[string]string{
			"repo":    repo.FullName,
			"private": strconv.FormatBool(repo.IsPrivate),
		},
	}
	message.Data, _ = json.Marshal(model.Event{
		Repo:  *repo,
		Build: *build,
	})
	s.pubsub.Publish(c, "topic/events", message)

	return nil
}

// Upload implements the rpc.Upload function
func (s *RPC) Upload(c context.Context, id string, file *rpc.File) error {
	procID, err := strconv.ParseInt(id, 10, 64)
	if err != nil {
		return err
	}

	pproc, err := s.store.ProcLoad(procID)
	if err != nil {
		log.Printf("error: cannot find parent proc with id %d: %s", procID, err)
		return err
	}

	build, err := s.store.GetBuild(pproc.BuildID)
	if err != nil {
		log.Printf("error: cannot find build with id %d: %s", pproc.BuildID, err)
		return err
	}

	proc, err := s.store.ProcChild(build, pproc.PID, file.Proc)
	if err != nil {
		log.Printf("error: cannot find child proc with name %s: %s", file.Proc, err)
		return err
	}

	if file.Mime == "application/json+logs" {
		return s.store.LogSave(
			proc,
			bytes.NewBuffer(file.Data),
		)
	}

	return s.store.FileCreate(&model.File{
		BuildID: proc.BuildID,
		ProcID:  proc.ID,
		Mime:    file.Mime,
		Name:    file.Name,
		Size:    file.Size,
		Time:    file.Time,
	},
		bytes.NewBuffer(file.Data),
	)
}

// Init implements the rpc.Init function
func (s *RPC) Init(c context.Context, id string, state rpc.State) error {
	procID, err := strconv.ParseInt(id, 10, 64)
	if err != nil {
		return err
	}

	proc, err := s.store.ProcLoad(procID)
	if err != nil {
		log.Printf("error: cannot find proc with id %d: %s", procID, err)
		return err
	}

	build, err := s.store.GetBuild(proc.BuildID)
	if err != nil {
		log.Printf("error: cannot find build with id %d: %s", proc.BuildID, err)
		return err
	}

	repo, err := s.store.GetRepo(build.RepoID)
	if err != nil {
		log.Printf("error: cannot find repo with id %d: %s", build.RepoID, err)
		return err
	}

	if build.Status == model.StatusPending {
		build.Status = model.StatusRunning
		build.Started = state.Started
		if err := s.store.UpdateBuild(build); err != nil {
			log.Printf("error: init: cannot update build_id %d state: %s", build.ID, err)
		}
	}

	defer func() {
		build.Procs, _ = s.store.ProcList(build)
		message := pubsub.Message{
			Labels: map[string]string{
				"repo":    repo.FullName,
				"private": strconv.FormatBool(repo.IsPrivate),
			},
		}
		message.Data, _ = json.Marshal(model.Event{
			Repo:  *repo,
			Build: *build,
		})
		s.pubsub.Publish(c, "topic/events", message)
	}()

	proc.Started = state.Started
	proc.State = model.StatusRunning
	return s.store.ProcUpdate(proc)
}

// Done implements the rpc.Done function
func (s *RPC) Done(c context.Context, id string, state rpc.State) error {
	procID, err := strconv.ParseInt(id, 10, 64)
	if err != nil {
		return err
	}

	proc, err := s.store.ProcLoad(procID)
	if err != nil {
		log.Printf("error: cannot find proc with id %d: %s", procID, err)
		return err
	}

	build, err := s.store.GetBuild(proc.BuildID)
	if err != nil {
		log.Printf("error: cannot find build with id %d: %s", proc.BuildID, err)
		return err
	}

	repo, err := s.store.GetRepo(build.RepoID)
	if err != nil {
		log.Printf("error: cannot find repo with id %d: %s", build.RepoID, err)
		return err
	}

	proc.Stopped = state.Finished
	proc.Error = state.Error
	proc.ExitCode = state.ExitCode
	proc.State = model.StatusSuccess
	if proc.ExitCode != 0 || proc.Error != "" {
		proc.State = model.StatusFailure
	}
	if err := s.store.ProcUpdate(proc); err != nil {
		log.Printf("error: done: cannot update proc_id %d state: %s", procID, err)
	}

	if err := s.queue.Done(c, id); err != nil {
		log.Printf("error: done: cannot ack proc_id %d: %s", procID, err)
	}

	done := false
	status := model.StatusSuccess
	// TODO handle this error
	procs, _ := s.store.ProcList(build)
	for _, p := range procs {
		if p.Running() && p.PPID == proc.PID {
			p.State = model.StatusSkipped
			if p.Started != 0 {
				p.State = model.StatusKilled
				p.Stopped = proc.Stopped
			}
			if err := s.store.ProcUpdate(p); err != nil {
				log.Printf("error: done: cannot update proc_id %d child state: %s", p.ID, err)
			}
		}
		if !p.Running() && p.PPID == 0 {
			done = true
			if p.Failing() {
				status = model.StatusFailure
			}
		}
	}
	if done {
		build.Status = status
		build.Finished = proc.Stopped
		if err := s.store.UpdateBuild(build); err != nil {
			log.Printf("error: done: cannot update build_id %d final state: %s", build.ID, err)
		}
	}

	if err := s.logger.Close(c, id); err != nil {
		log.Printf("error: done: cannot close build_id %d logger: %s", proc.ID, err)
	}

	build.Procs = procs
	message := pubsub.Message{
		Labels: map[string]string{
			"repo":    repo.FullName,
			"private": strconv.FormatBool(repo.IsPrivate),
		},
	}
	message.Data, _ = json.Marshal(model.Event{
		Repo:  *repo,
		Build: *build,
	})
	s.pubsub.Publish(c, "topic/events", message)

	return nil
}

// Log implements the rpc.Log function
func (s *RPC) Log(c context.Context, id string, line *rpc.Line) error {
	entry := new(logging.Entry)
	entry.Data, _ = json.Marshal(line)
	s.logger.Write(c, id, entry)
	return nil
}