feat(examples): add p/moul/udao package

Signed-off-by: moul <[email protected]>

examples/gno.land/p/moul/udao/udao.gno

@@ -0,0 +1,77 @@
+// Package udao defines minimal interfaces for Decentralized Autonomous Organizations (DAOs).
+// It intentionally does not expose members and votes, as these details are implementation-specific.
+// Instead, it focuses on providing an external view of proposals and their statuses,
+// which is what non-members and non-voters typically care about.
+//
+// The package is designed to allow for composable DAO patterns, enabling flexible
+// and modular implementations of various DAO structures and behaviors.
+package udao
+
+// DAO defines a minimal interface for a Decentralized Autonomous Organization
+// from an external point of view, hiding the internal details of members and voting.
+type DAO interface {
+	// Propose submits a new proposal to the DAO
+	Propose(proposal Proposal) (uint64, error)
+
+	// GetProposalStatus retrieves the current status and metrics of a specific proposal
+	GetProposalStatus(proposalID uint64) (ProposalStatus, error)
+
+	// Execute attempts to execute a proposal if it has passed
+	Execute(proposalID uint64) error
+
+	// GetProposal retrieves the details of a specific proposal
+	GetProposal(proposalID uint64) (Proposal, error)
+
+	// XXX: find a smart way to list proposals
+	// // ListProposalss retrieves a list of Proposals with pagination and optional filters
+	// ListDAOs(offset, limit int, filters ...ProposalFilter) ([]DAO, error)
+}
+
+// Proposal defines the interface for a DAO proposal
+type Proposal interface {
+	Title() string
+	Body() string
+	Constraints() []Constraint
+}
+
+// ProposalStatus represents the current status and metrics of a proposal
+type ProposalStatus struct {
+	// status
+	State ProposalState
+
+	// metrics
+	YayPercentage      float64
+	NayPercentage      float64
+	NonVoterPercentage float64
+	// XXX: other metrics?
+}
+
+// ProposalState represents the current state of a proposal
+type ProposalState int
+
+const (
+	Pending ProposalState = iota
+	Active
+	Passed
+	Rejected
+	Executed
+	Expired // XXX: better name for when it's expired but not because of time?
+)
+
+// Constraint defines an interface for proposal constraints
+type Constraint interface {
+	Validate() (bool, string)
+	Description() string
+}
+
+// ValidateConstraints checks if all constraints of a proposal are met
+func ValidateConstraints(p Proposal) (bool, []string) {
+	var unmetReasons []string
+	for _, constraint := range p.Constraints() {
+		valid, reason := constraint.Validate()
+		if !valid {
+			unmetReasons = append(unmetReasons, reason)
+		}
+	}
+	return len(unmetReasons) == 0, unmetReasons
+}