// Copyright 2022 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package runner

import (
	"context"
	"errors"
	"net/http"

	actions_model "code.gitea.io/gitea/models/actions"
	"code.gitea.io/gitea/modules/actions"
	"code.gitea.io/gitea/modules/json"
	"code.gitea.io/gitea/modules/log"
	actions_service "code.gitea.io/gitea/services/actions"

	runnerv1 "code.gitea.io/actions-proto-go/runner/v1"
	"code.gitea.io/actions-proto-go/runner/v1/runnerv1connect"
	"github.com/bufbuild/connect-go"
	gouuid "github.com/google/uuid"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
)

func NewRunnerServiceHandler() (string, http.Handler) {
	return runnerv1connect.NewRunnerServiceHandler(
		&Service{},
		connect.WithCompressMinBytes(1024),
		withRunner,
	)
}

var _ runnerv1connect.RunnerServiceClient = (*Service)(nil)

type Service struct {
	runnerv1connect.UnimplementedRunnerServiceHandler
}

// Register for new runner.
func (s *Service) Register(
	ctx context.Context,
	req *connect.Request[runnerv1.RegisterRequest],
) (*connect.Response[runnerv1.RegisterResponse], error) {
	if req.Msg.Token == "" || req.Msg.Name == "" {
		return nil, errors.New("missing runner token, name")
	}

	runnerToken, err := actions_model.GetRunnerToken(ctx, req.Msg.Token)
	if err != nil {
		return nil, errors.New("runner token not found")
	}

	if runnerToken.IsActive {
		return nil, errors.New("runner token has already activated")
	}

	// create new runner
	runner := &actions_model.ActionRunner{
		UUID:         gouuid.New().String(),
		Name:         req.Msg.Name,
		OwnerID:      runnerToken.OwnerID,
		RepoID:       runnerToken.RepoID,
		AgentLabels:  req.Msg.AgentLabels,
		CustomLabels: req.Msg.CustomLabels,
	}
	if err := runner.GenerateToken(); err != nil {
		return nil, errors.New("can't generate token")
	}

	// create new runner
	if err := actions_model.CreateRunner(ctx, runner); err != nil {
		return nil, errors.New("can't create new runner")
	}

	// update token status
	runnerToken.IsActive = true
	if err := actions_model.UpdateRunnerToken(ctx, runnerToken, "is_active"); err != nil {
		return nil, errors.New("can't update runner token status")
	}

	res := connect.NewResponse(&runnerv1.RegisterResponse{
		Runner: &runnerv1.Runner{
			Id:           runner.ID,
			Uuid:         runner.UUID,
			Token:        runner.Token,
			Name:         runner.Name,
			AgentLabels:  runner.AgentLabels,
			CustomLabels: runner.CustomLabels,
		},
	})

	return res, nil
}

// FetchTask assigns a task to the runner
func (s *Service) FetchTask(
	ctx context.Context,
	req *connect.Request[runnerv1.FetchTaskRequest],
) (*connect.Response[runnerv1.FetchTaskResponse], error) {
	runner := GetRunner(ctx)

	var task *runnerv1.Task
	if t, ok, err := pickTask(ctx, runner); err != nil {
		log.Error("pick task failed: %v", err)
		return nil, status.Errorf(codes.Internal, "pick task: %v", err)
	} else if ok {
		task = t
	}

	res := connect.NewResponse(&runnerv1.FetchTaskResponse{
		Task: task,
	})
	return res, nil
}

// UpdateTask updates the task status.
func (s *Service) UpdateTask(
	ctx context.Context,
	req *connect.Request[runnerv1.UpdateTaskRequest],
) (*connect.Response[runnerv1.UpdateTaskResponse], error) {
	{
		// to debug strange runner behaviors, it could be removed if all problems have been solved.
		stateMsg, _ := json.Marshal(req.Msg.State)
		log.Trace("update task with state: %s", stateMsg)
	}

	// Get Task first
	task, err := actions_model.GetTaskByID(ctx, req.Msg.State.Id)
	if err != nil {
		return nil, status.Errorf(codes.Internal, "can't find the task: %v", err)
	}
	if task.Status.IsCancelled() {
		return connect.NewResponse(&runnerv1.UpdateTaskResponse{
			State: &runnerv1.TaskState{
				Id:     req.Msg.State.Id,
				Result: task.Status.AsResult(),
			},
		}), nil
	}

	task, err = actions_model.UpdateTaskByState(ctx, req.Msg.State)
	if err != nil {
		return nil, status.Errorf(codes.Internal, "update task: %v", err)
	}

	if err := task.LoadJob(ctx); err != nil {
		return nil, status.Errorf(codes.Internal, "load job: %v", err)
	}

	if err := actions_service.CreateCommitStatus(ctx, task.Job); err != nil {
		log.Error("Update commit status failed: %v", err)
		// go on
	}

	if req.Msg.State.Result != runnerv1.Result_RESULT_UNSPECIFIED {
		if err := actions_service.EmitJobsIfReady(task.Job.RunID); err != nil {
			log.Error("Emit ready jobs of run %d: %v", task.Job.RunID, err)
		}
	}

	return connect.NewResponse(&runnerv1.UpdateTaskResponse{
		State: &runnerv1.TaskState{
			Id:     req.Msg.State.Id,
			Result: task.Status.AsResult(),
		},
	}), nil
}

// UpdateLog uploads log of the task.
func (s *Service) UpdateLog(
	ctx context.Context,
	req *connect.Request[runnerv1.UpdateLogRequest],
) (*connect.Response[runnerv1.UpdateLogResponse], error) {
	res := connect.NewResponse(&runnerv1.UpdateLogResponse{})

	task, err := actions_model.GetTaskByID(ctx, req.Msg.TaskId)
	if err != nil {
		return nil, status.Errorf(codes.Internal, "get task: %v", err)
	}
	ack := task.LogLength

	if len(req.Msg.Rows) == 0 || req.Msg.Index > ack || int64(len(req.Msg.Rows))+req.Msg.Index <= ack {
		res.Msg.AckIndex = ack
		return res, nil
	}

	if task.LogInStorage {
		return nil, status.Errorf(codes.AlreadyExists, "log file has been archived")
	}

	rows := req.Msg.Rows[ack-req.Msg.Index:]
	ns, err := actions.WriteLogs(ctx, task.LogFilename, task.LogSize, rows)
	if err != nil {
		return nil, status.Errorf(codes.Internal, "write logs: %v", err)
	}
	task.LogLength += int64(len(rows))
	for _, n := range ns {
		task.LogIndexes = append(task.LogIndexes, task.LogSize)
		task.LogSize += int64(n)
	}

	res.Msg.AckIndex = task.LogLength

	var remove func()
	if req.Msg.NoMore {
		task.LogInStorage = true
		remove, err = actions.TransferLogs(ctx, task.LogFilename)
		if err != nil {
			return nil, status.Errorf(codes.Internal, "transfer logs: %v", err)
		}
	}

	if err := actions_model.UpdateTask(ctx, task, "log_indexes", "log_length", "log_size", "log_in_storage"); err != nil {
		return nil, status.Errorf(codes.Internal, "update task: %v", err)
	}
	if remove != nil {
		remove()
	}

	return res, nil
}