// Package healthcheck provides health status reporting for the server.
package healthcheck

import (
	"context"
	"log/slog"
	"time"

	"git.eeqj.de/sneak/chat/internal/config"
	"git.eeqj.de/sneak/chat/internal/db"
	"git.eeqj.de/sneak/chat/internal/globals"
	"git.eeqj.de/sneak/chat/internal/logger"
	"go.uber.org/fx"
)

// Params defines the dependencies for creating a Healthcheck.
type Params struct {
	fx.In

	Globals  *globals.Globals
	Config   *config.Config
	Logger   *logger.Logger
	Database *db.Database
}

// Healthcheck tracks server uptime and provides health status.
type Healthcheck struct {
	// StartupTime records when the server started.
	StartupTime time.Time

	log    *slog.Logger
	params *Params
}

// New creates a new Healthcheck instance.
func New(
	lifecycle fx.Lifecycle, params Params,
) (*Healthcheck, error) {
	hcheck := &Healthcheck{ //nolint:exhaustruct // StartupTime set in OnStart
		params: &params,
		log:    params.Logger.Get(),
	}

	lifecycle.Append(fx.Hook{
		OnStart: func(_ context.Context) error {
			hcheck.StartupTime = time.Now()

			return nil
		},
		OnStop: func(_ context.Context) error {
			return nil
		},
	})

	return hcheck, nil
}

// Response is the JSON response returned by the health endpoint.
type Response struct {
	Status        string `json:"status"`
	Now           string `json:"now"`
	UptimeSeconds int64  `json:"uptimeSeconds"`
	UptimeHuman   string `json:"uptimeHuman"`
	Version       string `json:"version"`
	Appname       string `json:"appname"`
	Maintenance   bool   `json:"maintenanceMode"`
}

// Healthcheck returns the current health status of the server.
func (hcheck *Healthcheck) Healthcheck() *Response {
	return &Response{
		Status:        "ok",
		Now:           time.Now().UTC().Format(time.RFC3339Nano),
		UptimeSeconds: int64(hcheck.uptime().Seconds()),
		UptimeHuman:   hcheck.uptime().String(),
		Appname:       hcheck.params.Globals.Appname,
		Version:       hcheck.params.Globals.Version,
		Maintenance:   hcheck.params.Config.MaintenanceMode,
	}
}

func (hcheck *Healthcheck) uptime() time.Duration {
	return time.Since(hcheck.StartupTime)
}