package model

import (
	"encoding/json"
	"time"

	"gorm.io/gorm"
)

// Task status constants.
const (
	TaskStatusSubmitted   = "submitted"
	TaskStatusPreparing   = "preparing"
	TaskStatusDownloading = "downloading"
	TaskStatusReady       = "ready"
	TaskStatusQueued      = "queued"
	TaskStatusRunning     = "running"
	TaskStatusCompleted   = "completed"
	TaskStatusFailed      = "failed"
)

// Task step constants for step-level retry tracking.
const (
	TaskStepPreparing   = "preparing"
	TaskStepDownloading = "downloading"
	TaskStepSubmitting  = "submitting"
)

// Task represents an HPC task submitted through the application framework.
type Task struct {
	ID           int64           `gorm:"primaryKey;autoIncrement" json:"id"`
	TaskName     string          `gorm:"size:255" json:"task_name"`
	AppID        int64           `json:"app_id"`
	AppName      string          `gorm:"size:255" json:"app_name"`
	Status       string          `json:"status"`
	CurrentStep  string          `json:"current_step"`
	RetryCount   int             `json:"retry_count"`
	Values       json.RawMessage `gorm:"type:text" json:"values,omitempty"`
	InputFileIDs json.RawMessage `json:"input_file_ids" gorm:"column:input_file_ids;type:text"`
	Script       string          `json:"script,omitempty"`
	SlurmJobID   *int32          `json:"slurm_job_id,omitempty"`
	WorkDir      string          `json:"work_dir,omitempty"`
	Partition    string          `json:"partition,omitempty"`
	ErrorMessage string          `json:"error_message,omitempty"`
	UserID       string          `json:"user_id"`
	SubmittedAt  time.Time       `json:"submitted_at"`
	StartedAt    *time.Time      `json:"started_at,omitempty"`
	FinishedAt   *time.Time      `json:"finished_at,omitempty"`
	CreatedAt    time.Time       `json:"created_at"`
	UpdatedAt    time.Time       `json:"updated_at"`
	DeletedAt    gorm.DeletedAt  `gorm:"index" json:"deleted_at,omitempty"`
}

func (Task) TableName() string {
	return "hpc_tasks"
}

// CreateTaskRequest is the DTO for creating a new task.
type CreateTaskRequest struct {
	AppID        int64             `json:"app_id" binding:"required"`
	TaskName     string            `json:"task_name"`
	Values       map[string]string `json:"values"`
	InputFileIDs []int64           `json:"file_ids"`
}

// TaskResponse is the DTO returned in API responses.
type TaskResponse struct {
	ID           int64     `json:"id"`
	TaskName     string    `json:"task_name"`
	AppID        int64     `json:"app_id"`
	AppName      string    `json:"app_name"`
	Status       string    `json:"status"`
	CurrentStep  string    `json:"current_step"`
	RetryCount   int       `json:"retry_count"`
	SlurmJobID   *int32    `json:"slurm_job_id"`
	WorkDir      string    `json:"work_dir"`
	ErrorMessage string    `json:"error_message"`
	CreatedAt    time.Time `json:"created_at"`
	UpdatedAt    time.Time `json:"updated_at"`
}

// TaskListResponse is the paginated response for listing tasks.
type TaskListResponse struct {
	Items []TaskResponse `json:"items"`
	Total int64          `json:"total"`
}

// TaskListQuery contains query parameters for listing tasks.
type TaskListQuery struct {
	Page     int    `form:"page" json:"page,omitempty"`
	PageSize int    `form:"page_size" json:"page_size,omitempty"`
	Status   string `form:"status" json:"status,omitempty"`
}