package persona

import (
	"context"
	"errors"
	"time"
)

// ErrNotFound is returned when an agent lookup fails. Callers compare
// with errors.Is(err, ErrNotFound).
var ErrNotFound = errors.New("agent not found")

// Storage is the persistence interface for the agents system.
//
// Why: tests substitute fake implementations; production wires
// through pkg/logic/storage's Grand Storage which embeds this
// interface. Mirrors the three-layer pattern in
// pkg/logic/storage/CLAUDE.md (domain → GORM → DB).
//
// What: Phase 1 CRUD plus Phase 3 trigger queries
// (ListDueScheduled, GetAgentByWebhookSecret,
// ListAgentsByChatbotChannelFilter, MarkScheduledRun). Trigger
// queries are read by the agentsched runner, webhook router, and
// chatbot tool provider; all are gated behind the
// agents.triggers.enabled convar so old skill-driven paths keep
// running until the convar flips.
//
// Test: see storage_round_trip_test.go for round-trip coverage.
type Storage interface {
	// (Mort's Discord command-binding CRUD — the CommandBindingStorage
	// embedding — stays a host concern and is NOT part of the executus
	// persona Storage seam.)

	// InitializeAgentStorage prepares storage (e.g. AutoMigrate)
	// and is idempotent. Called from the grand storage's
	// InitializeAll path.
	InitializeAgentStorage(ctx context.Context) error

	// SaveAgent creates or updates an Agent by ID. ID must be
	// non-empty (Phase 1 admin commands mint a UUID).
	SaveAgent(ctx context.Context, a *Agent) error

	// GetAgent returns the agent with the given ID, or ErrNotFound.
	GetAgent(ctx context.Context, id string) (*Agent, error)

	// GetAgentByName resolves (owner_id, name) → agent. ownerID
	// must match exactly (Phase 1 has no shared/public visibility
	// yet; every agent is owned).
	GetAgentByName(ctx context.Context, ownerID, name string) (*Agent, error)

	// ListAgents returns every agent owned by the given member ID,
	// sorted by Name ASC.
	ListAgents(ctx context.Context, ownerID string) ([]*Agent, error)

	// ListAllAgents returns every agent across all owners, sorted by
	// (OwnerID ASC, Name ASC) so builtin rows (OwnerID="builtin")
	// group together, then numeric Discord-ID owners in lexical order,
	// then chatbot-shadow rows whose OwnerID is the chatbot owner's
	// Discord ID but whose Name carries the "chatbot:" prefix.
	//
	// Why: Phase 1 admin commands ran owner-scoped (a steve-owned
	// agent list shows ONLY steve's rows), which hid builtin and
	// shadow Agents from the admin view. `.agent list` for admins now
	// uses this method to surface every row. Non-admin invocations
	// (or `.agent list --mine`) keep using ListAgents.
	//
	// Storage MAY back this with a single full-table scan — admin
	// row counts are small (dozens to low hundreds), so no need for
	// pagination at this phase.
	ListAllAgents(ctx context.Context) ([]*Agent, error)

	// DeleteAgent removes an agent by ID. Idempotent — deleting a
	// missing row returns nil.
	DeleteAgent(ctx context.Context, id string) error

	// GetAgentByWebhookSecret resolves a posted /webhooks/<secret> URL
	// to the matching agent. Returns ErrNotFound when no agent has
	// the secret. Phase 3 webhook router consults this AFTER the
	// existing Skill lookup falls through, but only when
	// agents.triggers.enabled is true.
	//
	// Empty secret is rejected with ErrNotFound (empty WebhookSecret
	// rows are NOT webhook-enabled — the application layer guards
	// this, the lookup defends against accidental match).
	GetAgentByWebhookSecret(ctx context.Context, secret string) (*Agent, error)

	// ListAgentsByChatbotChannelFilter returns every agent with a
	// non-empty ChatbotChannelFilter. Phase 3 chatbot tool provider
	// uses this on every chatbot turn to assemble the per-channel
	// tool list (gated by agents.triggers.enabled). The result is
	// not channel-filtered here — the provider applies the channel
	// filter predicate (registered in skills.ChannelFilterRegistry)
	// to each row.
	//
	// Why no channel filter at the storage layer: the filter is a
	// runtime predicate (e.g. dm_only depends on the live Discord
	// channel kind cache), not a static column we can index on.
	ListAgentsByChatbotChannelFilter(ctx context.Context) ([]*Agent, error)

	// ListScheduledAgents returns every agent with a non-empty
	// Schedule whose NextRunAt is at or before `dueBefore`. Result
	// is ordered by NextRunAt ASC so the scheduler runner can drain
	// in oldest-due-first order. Mirrors skills.Storage.ListDueScheduled.
	//
	// Phase 3 scheduler reads this on every tick when
	// agents.triggers.enabled is true. The (Schedule, NextRunAt)
	// composite index backs the query — see gorm tags on gormAgent.
	ListScheduledAgents(ctx context.Context, dueBefore time.Time) ([]*Agent, error)

	// MarkAgentScheduledRun atomically updates LastScheduledRunAt
	// and NextRunAt for the given agent. Called by the agentsched
	// runner after each scheduled invocation. Mirrors
	// skills.Storage.MarkScheduledRun semantics.
	MarkAgentScheduledRun(ctx context.Context, agentID string, ranAt, nextAt time.Time) error
}