package app

import (
	"context"
	"fmt"
	"io"
	"net/http"
	"strings"
	"sync/atomic"
	"time"

	"github.com/gochat/gochat/internal/config"
	"github.com/gochat/gochat/internal/database"
	basehandler "github.com/gochat/gochat/internal/handler"
	"github.com/gochat/gochat/internal/search"
	"github.com/redis/go-redis/v9"
	"gorm.io/gorm"
)

func newReadinessChecks(cfg *config.Config, db *gorm.DB, rdb redis.UniversalClient, ready *atomic.Bool) []basehandler.DependencyCheck {
	latestMigration, latestMigrationErr := database.LatestVersion(cfg.Database.GetMigrationsPath())
	checks := []basehandler.DependencyCheck{
		{Name: "redis", Check: func(ctx context.Context) error { return rdb.Ping(ctx).Err() }},
		{Name: "migrations", Check: func(ctx context.Context) error {
			if latestMigrationErr != nil {
				return latestMigrationErr
			}
			return database.CheckVersion(ctx, db, latestMigration)
		}},
		{Name: "draining", Check: func(context.Context) error {
			if !ready.Load() {
				return fmt.Errorf("shutdown in progress")
			}
			return nil
		}},
	}
	if !strings.EqualFold(cfg.Search.Engine, search.EngineMeilisearch) {
		return checks
	}
	searchClient := &http.Client{Timeout: time.Duration(cfg.Search.TimeoutSeconds) * time.Second}
	return append(checks, basehandler.DependencyCheck{Name: "search", Check: func(ctx context.Context) error {
		request, err := http.NewRequestWithContext(ctx, http.MethodGet, strings.TrimRight(cfg.Search.Host, "/")+"/health", nil)
		if err != nil {
			return err
		}
		response, err := searchClient.Do(request)
		if err != nil {
			return err
		}
		defer response.Body.Close()
		_, _ = io.Copy(io.Discard, response.Body)
		if response.StatusCode != http.StatusOK {
			return fmt.Errorf("search health returned %s", response.Status)
		}
		return nil
	}})
}