package models

import (
	"time"

	"gorm.io/gorm"
)

type Task struct {
	ID        uint           `json:"id" gorm:"primaryKey"`
	CreatedAt time.Time      `json:"created_at"`
	UpdatedAt time.Time      `json:"updated_at"`
	DeletedAt gorm.DeletedAt `json:"deleted_at" gorm:"index"`

	Title       string     `json:"title" gorm:"not null"`
	Description string     `json:"description"`
	Status      string     `json:"status" gorm:"default:'todo'"`     // todo, in_progress, review, done
	Priority    string     `json:"priority" gorm:"default:'medium'"` // low, medium, high, urgent
	DueDate     *time.Time `json:"due_date"`
	CompletedAt *time.Time `json:"completed_at"`
	Position    int        `json:"position" gorm:"default:0"` // For ordering in kanban board

	// Foreign Keys
	ProjectID    uint  `json:"project_id" gorm:"not null"`
	AssignedToID *uint `json:"assigned_to_id"`
	CreatedByID  uint  `json:"created_by_id" gorm:"not null"`

	// Relationships
	Project    Project      `json:"project" gorm:"foreignKey:ProjectID"`
	AssignedTo *User        `json:"assigned_to" gorm:"foreignKey:AssignedToID"`
	CreatedBy  User         `json:"created_by" gorm:"foreignKey:CreatedByID"`
	Comments   []Comment    `json:"comments" gorm:"foreignKey:TaskID"`
	Files      []FileUpload `json:"files" gorm:"foreignKey:TaskID"`
	Subtasks   []Subtask    `json:"subtasks" gorm:"foreignKey:ParentTaskID"`
	Labels     []Label      `json:"labels" gorm:"many2many:task_labels"`
}

type Subtask struct {
	ID        uint           `json:"id" gorm:"primaryKey"`
	CreatedAt time.Time      `json:"created_at"`
	UpdatedAt time.Time      `json:"updated_at"`
	DeletedAt gorm.DeletedAt `json:"deleted_at" gorm:"index"`

	Title       string     `json:"title" gorm:"not null"`
	Description string     `json:"description"`
	Status      string     `json:"status" gorm:"default:'todo'"` // todo, in_progress, done
	Position    int        `json:"position" gorm:"default:0"`
	CompletedAt *time.Time `json:"completed_at"`

	// Foreign Keys
	ParentTaskID uint  `json:"parent_task_id" gorm:"not null"`
	AssignedToID *uint `json:"assigned_to_id"`

	// Relationships
	ParentTask Task  `json:"parent_task" gorm:"foreignKey:ParentTaskID"`
	AssignedTo *User `json:"assigned_to" gorm:"foreignKey:AssignedToID"`
}

type Label struct {
	ID        uint           `json:"id" gorm:"primaryKey"`
	CreatedAt time.Time      `json:"created_at"`
	UpdatedAt time.Time      `json:"updated_at"`
	DeletedAt gorm.DeletedAt `json:"deleted_at" gorm:"index"`

	Name  string `json:"name" gorm:"not null"`
	Color string `json:"color" gorm:"default:'#6b7280'"` // Hex color

	// Foreign Keys
	ProjectID uint `json:"project_id" gorm:"not null"`

	// Relationships
	Project Project `json:"project" gorm:"foreignKey:ProjectID"`
	Tasks   []Task  `json:"tasks" gorm:"many2many:task_labels"`
}

type Comment struct {
	ID        uint           `json:"id" gorm:"primaryKey"`
	CreatedAt time.Time      `json:"created_at"`
	UpdatedAt time.Time      `json:"updated_at"`
	DeletedAt gorm.DeletedAt `json:"deleted_at" gorm:"index"`

	Content string `json:"content" gorm:"not null"`

	// Foreign Keys
	TaskID uint `json:"task_id" gorm:"not null"`
	UserID uint `json:"user_id" gorm:"not null"`

	// Relationships
	Task Task `json:"task" gorm:"foreignKey:TaskID"`
	User User `json:"user" gorm:"foreignKey:UserID"`
}

// IsOverdue checks if the task is overdue
func (t *Task) IsOverdue() bool {
	if t.DueDate == nil {
		return false
	}
	return t.Status != "done" && t.DueDate.Before(time.Now())
}

// GetCompletionPercentage returns the completion percentage based on subtasks
func (t *Task) GetCompletionPercentage() int {
	if len(t.Subtasks) == 0 {
		if t.Status == "done" {
			return 100
		}
		return 0
	}

	completed := 0
	for _, subtask := range t.Subtasks {
		if subtask.Status == "done" {
			completed++
		}
	}

	return (completed * 100) / len(t.Subtasks)
}

// MarkAsCompleted marks the task as completed
func (t *Task) MarkAsCompleted() {
	t.Status = "done"
	now := time.Now()
	t.CompletedAt = &now
}