package domain

import (
	"errors"

	"git.cin.su/m/Assistant/contracts/authority"
	contract "git.cin.su/m/Assistant/contracts/work"
)

var (
	ErrTaskNotFound       = errors.New("task not found")
	ErrTaskTargetMismatch = errors.New("task target does not match canonical task")
	ErrRevisionConflict   = errors.New("task revision conflict")
)

type Task struct {
	ID       contract.TaskID
	GoalID   contract.GoalID
	ScopeID  authority.ScopeID
	Revision contract.TaskRevision
}

// Store models owner-local task state for the walking skeleton. A caller must
// present all target integrity fields; no cross-owner lookup is performed.
type Store struct {
	tasks map[contract.TaskID]Task
}

func NewStore(tasks []Task) Store {
	stored := make(map[contract.TaskID]Task, len(tasks))
	for _, task := range tasks {
		stored[task.ID] = task
	}
	return Store{tasks: stored}
}

func (s *Store) Commit(target contract.TaskTarget) (Task, error) {
	task, ok := s.tasks[target.TaskID]
	if !ok {
		return Task{}, ErrTaskNotFound
	}
	if task.GoalID != target.GoalID || task.ScopeID != target.ScopeID {
		return Task{}, ErrTaskTargetMismatch
	}
	if task.Revision != target.Revision {
		return Task{}, ErrRevisionConflict
	}
	task.Revision++
	s.tasks[task.ID] = task
	return task, nil
}