package projectinstance

import (
	"errors"

	"chat-agent-system/internal/workflowdef"
)

var (
	ErrNotAvailable                = errors.New("project instance store not available")
	ErrProjectNotFound             = errors.New("project not found")
	ErrForbiddenNotCreator         = errors.New("forbidden: only project creator can configure workflow")
	ErrPlanFrozen                  = errors.New("plan frozen: workflow already active")
	ErrWorkflowSwitchFrozen        = errors.New("workflow switch frozen: definition cannot change after activation")
	ErrWorkflowAlreadyActive       = errors.New("workflow already active for project")
	ErrPlanChangedReconfirm        = errors.New("plan changed: reconfirm required")
	ErrInvalidPlan                 = errors.New("invalid workflow plan")
	ErrValidationFailed            = errors.New("workflow plan validation failed")
	ErrTokenInvalid                = errors.New("activation token invalid or expired")
	ErrConcurrentConflict          = errors.New("conflict: project version mismatch")
	ErrPlanRevisionConflict        = errors.New("conflict: plan revision mismatch")
	ErrWorkflowVersionNotFound     = errors.New("workflow version not found or not published")
	ErrLegacySwitchBlocked         = errors.New("legacy workflow switch blocked: use project settings activation")
	ErrInstanceNotFound            = errors.New("workflow instance not found")
	ErrStageGateNotReady           = errors.New("stage gate not ready: required documents not approved")
	ErrStageNotActive              = errors.New("stage is not the active stage")
	ErrStageNotCompleted           = errors.New("stage is not completed")
	ErrRecheckAckRequired          = errors.New("recheck acknowledgement required")
	ErrInvalidStage                = errors.New("invalid stage key for instance")
	ErrInstanceRevisionConflict    = errors.New("conflict: instance config revision mismatch")
	ErrEmptyWorkflow               = errors.New("empty workflow: at least one enabled document required to activate")
	ErrTerminationNotAllowed       = errors.New("termination not allowed for instance state")
	ErrAuthorOnlyPolicyDisabled    = errors.New("author-only approval policy disabled")
	ErrAuthorOnlyPolicyUnavailable = errors.New("author-only approval policy store unavailable")
	ErrAuthorOnlyPolicyChanged     = errors.New("author-only approval policy changed since preview")
	ErrForbiddenDutyReassign       = errors.New("forbidden: not allowed to reassign document duties")
	ErrDocTaskNotFound             = errors.New("document task not found or disabled")
)

// DocTaskBusyError 文档小队任务运行中，禁止改派。
type DocTaskBusyError struct {
	TaskKey string
	Reason  string
}

func (e *DocTaskBusyError) Error() string {
	if e == nil {
		return "document task busy"
	}
	if e.Reason != "" {
		return e.Reason
	}
	return "document task busy: squad run in progress"
}

func (e *DocTaskBusyError) ErrorCode() string { return "DOC_TASK_BUSY" }

func (e *DocTaskBusyError) Is(target error) bool {
	_, ok := target.(*DocTaskBusyError)
	return ok
}

var ErrDocTaskBusy = &DocTaskBusyError{}

// ValidationError 保留具体校验问题，供 HTTP 层返回可操作的错误信息。
type ValidationError struct {
	Issues []workflowdef.ValidationIssue
}

func (e *ValidationError) Error() string {
	return ErrValidationFailed.Error()
}

func (e *ValidationError) Unwrap() error {
	return ErrValidationFailed
}

func newValidationError(result workflowdef.ValidationResult) error {
	return &ValidationError{Issues: result.Issues}
}