package server

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"log/slog"
	"net/http"

	"level3.git.onstackit.cloud/LEVEL3/gabriel/src/api"
	"level3.git.onstackit.cloud/LEVEL3/gabriel/src/config"
	"level3.git.onstackit.cloud/LEVEL3/gabriel/src/search"
)

type PagedbService interface {
	Create(ctx context.Context, instanceId, owner string) (api.Instance, error)
	Get(ctx context.Context, instanceId, owner string) (api.Instance, error)
	List(ctx context.Context, owner string) ([]api.Instance, error)
	Delete(ctx context.Context, instanceId, owner string) error
	ValidateInstanceOwner(ctx context.Context, instanceId, owner string) error
}

type SearchService interface {
	Index(ctx context.Context, instanceId, owner, text string, index *string) (search.IndexedDocument, error)
	Search(ctx context.Context, instanceId, owner string, params api.SearchDocsParams) ([]api.Document, error)
	Delete(ctx context.Context, instanceId, owner, docId string, params api.DeleteDocParams) error
	ListIndices(ctx context.Context, instanceId, owner string) ([]string, error)
}

type LogsStore interface {
	Add(instanceId string, operation api.LogEntryOperation, status api.LogEntryStatus, message string, username string)
	List(instanceId string) []api.LogEntry
}

type Server struct {
	pagedb     PagedbService
	search     SearchService
	logs       LogsStore
	inviteCode string
}

func NewServer(pagedbSvc PagedbService, searchSvc SearchService, logsStore LogsStore, inviteCode string) *Server {
	return &Server{
		pagedb:     pagedbSvc,
		search:     searchSvc,
		logs:       logsStore,
		inviteCode: inviteCode,
	}
}

func (s *Server) usernameFromCtx(r *http.Request) (string, bool) {
	u, ok := r.Context().Value(config.UsernameKey).(string)
	if !ok {
		slog.Error("Username not found in context")
		return "", false
	}
	return u, true
}

func writeJSONResponse(w http.ResponseWriter, statusCode int, data any) {
	slog.Debug("Writing JSON response", slog.Int("statusCode", statusCode))
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(statusCode)
	if err := json.NewEncoder(w).Encode(data); err != nil {
		slog.Error("failed to write JSON response", slog.String("error", err.Error()))
	}
}

func reqBody[T any](r io.Reader) (*T, error) {
	var t T
	if err := json.NewDecoder(r).Decode(&t); err != nil {
		return nil, fmt.Errorf("failed to parse %T: %w", t, err)
	}
	return &t, nil
}

func writeServiceError(w http.ResponseWriter, err error) {
	if se, ok := err.(*search.ServiceError); ok {
		writeJSONResponse(w, se.Code, map[string]string{"error": se.Msg})
		return
	}
	slog.Error("internal server error", "error", err)
	writeJSONResponse(w, http.StatusInternalServerError, map[string]string{"error": "internal server error"})
}