package api

import (
	"context"
	"encoding/json"
	"net/http"
	"sync"

	"github.com/rs/zerolog"

	"git.omukk.dev/wrenn/sandbox/envd/internal/execcontext"
	"git.omukk.dev/wrenn/sandbox/envd/internal/host"
	"git.omukk.dev/wrenn/sandbox/envd/internal/utils"
)

// MMDSClient provides access to MMDS metadata.
type MMDSClient interface {
	GetAccessTokenHash(ctx context.Context) (string, error)
}

// DefaultMMDSClient is the production implementation that calls the real MMDS endpoint.
type DefaultMMDSClient struct{}

func (c *DefaultMMDSClient) GetAccessTokenHash(ctx context.Context) (string, error) {
	return host.GetAccessTokenHashFromMMDS(ctx)
}

type API struct {
	isNotFC     bool
	logger      *zerolog.Logger
	accessToken *SecureToken
	defaults    *execcontext.Defaults

	mmdsChan      chan *host.MMDSOpts
	hyperloopLock sync.Mutex
	mmdsClient    MMDSClient

	lastSetTime *utils.AtomicMax
	initLock    sync.Mutex
}

func New(l *zerolog.Logger, defaults *execcontext.Defaults, mmdsChan chan *host.MMDSOpts, isNotFC bool) *API {
	return &API{
		logger:      l,
		defaults:    defaults,
		mmdsChan:    mmdsChan,
		isNotFC:     isNotFC,
		mmdsClient:  &DefaultMMDSClient{},
		lastSetTime: utils.NewAtomicMax(),
		accessToken: &SecureToken{},
	}
}

func (a *API) GetHealth(w http.ResponseWriter, r *http.Request) {
	defer r.Body.Close()

	a.logger.Trace().Msg("Health check")

	w.Header().Set("Cache-Control", "no-store")
	w.Header().Set("Content-Type", "")

	w.WriteHeader(http.StatusNoContent)
}

func (a *API) GetMetrics(w http.ResponseWriter, r *http.Request) {
	defer r.Body.Close()

	a.logger.Trace().Msg("Get metrics")

	w.Header().Set("Cache-Control", "no-store")
	w.Header().Set("Content-Type", "application/json")

	metrics, err := host.GetMetrics()
	if err != nil {
		a.logger.Error().Err(err).Msg("Failed to get metrics")
		w.WriteHeader(http.StatusInternalServerError)

		return
	}

	w.WriteHeader(http.StatusOK)
	if err := json.NewEncoder(w).Encode(metrics); err != nil {
		a.logger.Error().Err(err).Msg("Failed to encode metrics")
	}
}

func (a *API) getLogger(err error) *zerolog.Event {
	if err != nil {
		return a.logger.Error().Err(err) //nolint:zerologlint // this is only prep
	}

	return a.logger.Info() //nolint:zerologlint // this is only prep
}