package httpserver

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

	"solopm.com/solopm-server/internal/config"
)

// DBPinger is the subset of *pgxpool.Pool used for health checks.
type DBPinger interface {
	Ping(ctx context.Context) error
}

type healthResponse struct {
	Status      string `json:"status"`
	Version     string `json:"version"`
	Database    string `json:"database"`
	Meilisearch string `json:"meilisearch"`
	SMTP        string `json:"smtp"`
}

func healthzHandler(cfg *config.Config, db DBPinger, version string) http.HandlerFunc {
	httpClient := &http.Client{Timeout: 2 * time.Second}

	return func(w http.ResponseWriter, r *http.Request) {
		ctx, cancel := context.WithTimeout(r.Context(), 2*time.Second)
		defer cancel()

		resp := healthResponse{
			Status:      "ok",
			Version:     version,
			Meilisearch: "absent",
			SMTP:        "absent",
		}

		if err := db.Ping(ctx); err != nil {
			resp.Status = "error"
			resp.Database = "unreachable"
		} else {
			resp.Database = "ok"
		}

		if cfg.SearchEnabled() {
			req, err := http.NewRequestWithContext(ctx, http.MethodGet, cfg.MeiliURL+"/health", nil)
			if err == nil {
				if hr, err := httpClient.Do(req); err == nil {
					_ = hr.Body.Close()
					if hr.StatusCode == http.StatusOK {
						resp.Meilisearch = "ok"
					} else {
						resp.Meilisearch = "unreachable"
					}
				} else {
					resp.Meilisearch = "unreachable"
				}
			}
		}

		if cfg.EmailEnabled() {
			resp.SMTP = "ok"
		}

		status := http.StatusOK
		if resp.Status != "ok" {
			status = http.StatusServiceUnavailable
		}

		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(status)
		_ = json.NewEncoder(w).Encode(resp)
	}
}