// Package openapi registers anchorage's HTTP surface on a huma API instance.
//
// Handlers are grouped by domain (pins, tokens, orgs, audit) and registered
// via huma's code-first operations. The generated OpenAPI 3.1 spec lives at
// GET /openapi.json; Scalar UI is served at GET /docs.
package openapi

import (
	"context"

	"github.com/danielgtaylor/huma/v2"
	"github.com/danielgtaylor/huma/v2/adapters/humafiber"
	"github.com/gofiber/fiber/v2"
)

// New creates a huma.API configured to match the anchorage spec.
//
// The returned huma.API is not yet populated with routes — callers
// (see internal/app/anchorage) wire in domain handlers via Register*
// functions exported by their respective packages.
func New(app *fiber.App) huma.API {
	cfg := huma.DefaultConfig("anchorage", "0.1.0")
	cfg.OpenAPI.Info.Description = "Highly-available IPFS Pinning Service API. Wire-compatible with the IPFS Pinning Services API spec, plus org/admin extensions."
	cfg.Servers = []*huma.Server{
		{URL: "/v1", Description: "Default v1 endpoint"},
	}
	cfg.Components.SecuritySchemes = map[string]*huma.SecurityScheme{
		"accessToken": {
			Type:         "http",
			Scheme:       "bearer",
			BearerFormat: "JWT",
		},
	}
	return humafiber.New(app, cfg)
}

// HealthResponse is the body of /health (liveness probe).
type HealthResponse struct {
	Body struct {
		Status string `json:"status" example:"ok"`
	}
}

// ReadyResponse is the body of /ready (readiness probe). Includes the
// Reconciler drift count so operators can alert on out-of-sync nodes
// without scraping /metrics.
type ReadyResponse struct {
	Body struct {
		Status string `json:"status" example:"ok"`
		// Drift is the current reconciler drift count (pins the store
		// believes this node holds vs. pins actually in Kubo's pinset).
		// 0 on a healthy node. Non-zero is not inherently "not ready" —
		// a drifted node still serves requests fine — but operators
		// alert on sustained non-zero values.
		Drift int64 `json:"drift"`
	}
}

// ReadyState is the signal the readyz callback returns to
// RegisterHealth. Ready controls the HTTP status (true → 200, false →
// 503). Drift is surfaced in the body regardless.
type ReadyState struct {
	Ready  bool
	Reason string
	Drift  int64
}

// RegisterHealth registers /health and /ready.
//
// /health is a liveness probe: the process is alive and the API is
// reachable. /ready is a readiness probe: returns 503 while the node
// is drained or while mandatory dependencies (Postgres, NATS) are
// unavailable. The readyz callback receives the per-request context so
// dependency probes are scoped to the request (not the app's root
// ctx, which would stall health-checks mid-shutdown).
func RegisterHealth(api huma.API, readyz func(ctx context.Context) ReadyState) {
	huma.Register(api, huma.Operation{
		OperationID: "getHealth",
		Method:      "GET",
		Path:        "/health",
		Summary:     "Liveness probe",
	}, func(_ context.Context, _ *struct{}) (*HealthResponse, error) {
		out := &HealthResponse{}
		out.Body.Status = "ok"
		return out, nil
	})

	huma.Register(api, huma.Operation{
		OperationID: "getReady",
		Method:      "GET",
		Path:        "/ready",
		Summary:     "Readiness probe (also reports reconciler drift)",
	}, func(ctx context.Context, _ *struct{}) (*ReadyResponse, error) {
		state := readyz(ctx)
		out := &ReadyResponse{}
		out.Body.Drift = state.Drift
		if state.Ready {
			out.Body.Status = "ok"
			return out, nil
		}
		out.Body.Status = "not-ready: " + state.Reason
		return out, huma.Error503ServiceUnavailable("not ready: " + state.Reason)
	})
}