package httpapp

import (
	"net/http"
	"strings"

	"gitea.avt.data-center.id/othman.suseno/atlas/internal/errors"
)

// methodHandler routes requests based on HTTP method
func methodHandler(get, post, put, delete, patch http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		switch r.Method {
		case http.MethodGet:
			if get != nil {
				get(w, r)
			} else {
				http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
			}
		case http.MethodPost:
			if post != nil {
				post(w, r)
			} else {
				http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
			}
		case http.MethodPut:
			if put != nil {
				put(w, r)
			} else {
				http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
			}
		case http.MethodDelete:
			if delete != nil {
				delete(w, r)
			} else {
				http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
			}
		case http.MethodPatch:
			if patch != nil {
				patch(w, r)
			} else {
				http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
			}
		default:
			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		}
	}
}

// pathParam extracts the last segment from a path
func pathParam(r *http.Request, prefix string) string {
	path := strings.TrimPrefix(r.URL.Path, prefix)
	path = strings.Trim(path, "/")
	parts := strings.Split(path, "/")
	if len(parts) > 0 {
		return parts[len(parts)-1]
	}
	return ""
}

// handlePoolOps routes pool operations by method
func (a *App) handlePoolOps(w http.ResponseWriter, r *http.Request) {
	// Extract pool name from path like /api/v1/pools/tank
	name := pathParam(r, "/api/v1/pools/")
	if name == "" {
		writeError(w, errors.ErrBadRequest("pool name required"))
		return
	}

	if strings.HasSuffix(r.URL.Path, "/scrub") {
		if r.Method == http.MethodPost {
			a.handleScrubPool(w, r)
		} else if r.Method == http.MethodGet {
			a.handleGetScrubStatus(w, r)
		} else {
			writeError(w, errors.NewAPIError(errors.ErrCodeBadRequest, "method not allowed", http.StatusMethodNotAllowed))
		}
		return
	}

	if strings.HasSuffix(r.URL.Path, "/export") {
		if r.Method == http.MethodPost {
			a.handleExportPool(w, r)
		} else {
			writeError(w, errors.NewAPIError(errors.ErrCodeBadRequest, "method not allowed", http.StatusMethodNotAllowed))
		}
		return
	}

	methodHandler(
		func(w http.ResponseWriter, r *http.Request) { a.handleGetPool(w, r) },
		nil,
		nil,
		func(w http.ResponseWriter, r *http.Request) { a.handleDeletePool(w, r) },
		nil,
	)(w, r)
}

// handleDatasetOps routes dataset operations by method
func (a *App) handleDatasetOps(w http.ResponseWriter, r *http.Request) {
	methodHandler(
		func(w http.ResponseWriter, r *http.Request) { a.handleGetDataset(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleCreateDataset(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleUpdateDataset(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleDeleteDataset(w, r) },
		nil,
	)(w, r)
}

// handleZVOLOps routes ZVOL operations by method
func (a *App) handleZVOLOps(w http.ResponseWriter, r *http.Request) {
	methodHandler(
		func(w http.ResponseWriter, r *http.Request) { a.handleGetZVOL(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleCreateZVOL(w, r) },
		nil,
		func(w http.ResponseWriter, r *http.Request) { a.handleDeleteZVOL(w, r) },
		nil,
	)(w, r)
}

// handleSnapshotOps routes snapshot operations by method
func (a *App) handleSnapshotOps(w http.ResponseWriter, r *http.Request) {
	methodHandler(
		func(w http.ResponseWriter, r *http.Request) { a.handleGetSnapshot(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleCreateSnapshot(w, r) },
		nil,
		func(w http.ResponseWriter, r *http.Request) { a.handleDeleteSnapshot(w, r) },
		nil,
	)(w, r)
}

// handleSnapshotPolicyOps routes snapshot policy operations by method
func (a *App) handleSnapshotPolicyOps(w http.ResponseWriter, r *http.Request) {
	methodHandler(
		func(w http.ResponseWriter, r *http.Request) { a.handleGetSnapshotPolicy(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleCreateSnapshotPolicy(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleUpdateSnapshotPolicy(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleDeleteSnapshotPolicy(w, r) },
		nil,
	)(w, r)
}

// handleSMBShareOps routes SMB share operations by method
func (a *App) handleSMBShareOps(w http.ResponseWriter, r *http.Request) {
	methodHandler(
		func(w http.ResponseWriter, r *http.Request) { a.handleGetSMBShare(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleCreateSMBShare(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleUpdateSMBShare(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleDeleteSMBShare(w, r) },
		nil,
	)(w, r)
}

// handleNFSExportOps routes NFS export operations by method
func (a *App) handleNFSExportOps(w http.ResponseWriter, r *http.Request) {
	methodHandler(
		func(w http.ResponseWriter, r *http.Request) { a.handleGetNFSExport(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleCreateNFSExport(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleUpdateNFSExport(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleDeleteNFSExport(w, r) },
		nil,
	)(w, r)
}

// handleISCSITargetOps routes iSCSI target operations by method
func (a *App) handleBackupOps(w http.ResponseWriter, r *http.Request) {
	backupID := pathParam(r, "/api/v1/backups/")
	if backupID == "" {
		writeError(w, errors.ErrBadRequest("backup id required"))
		return
	}

	switch r.Method {
	case http.MethodGet:
		// Check if it's a verify request
		if r.URL.Query().Get("verify") == "true" {
			a.handleVerifyBackup(w, r)
		} else {
			a.handleGetBackup(w, r)
		}
	case http.MethodPost:
		// Restore backup (POST /api/v1/backups/{id}/restore)
		if strings.HasSuffix(r.URL.Path, "/restore") {
			a.handleRestoreBackup(w, r)
		} else {
			writeError(w, errors.ErrBadRequest("invalid backup operation"))
		}
	case http.MethodDelete:
		a.handleDeleteBackup(w, r)
	default:
		writeError(w, errors.ErrBadRequest("method not allowed"))
	}
}

func (a *App) handleISCSITargetOps(w http.ResponseWriter, r *http.Request) {
	id := pathParam(r, "/api/v1/iscsi/targets/")
	if id == "" {
		writeError(w, errors.ErrBadRequest("target id required"))
		return
	}

	if strings.HasSuffix(r.URL.Path, "/connection") {
		if r.Method == http.MethodGet {
			a.handleGetISCSIConnectionInstructions(w, r)
		} else {
			writeError(w, errors.NewAPIError(errors.ErrCodeBadRequest, "method not allowed", http.StatusMethodNotAllowed))
		}
		return
	}

	if strings.HasSuffix(r.URL.Path, "/luns") {
		if r.Method == http.MethodPost {
			a.handleAddLUN(w, r)
			return
		}
		writeError(w, errors.NewAPIError(errors.ErrCodeBadRequest, "method not allowed", http.StatusMethodNotAllowed))
		return
	}

	if strings.HasSuffix(r.URL.Path, "/luns/remove") {
		if r.Method == http.MethodPost {
			a.handleRemoveLUN(w, r)
			return
		}
		writeError(w, errors.NewAPIError(errors.ErrCodeBadRequest, "method not allowed", http.StatusMethodNotAllowed))
		return
	}

	methodHandler(
		func(w http.ResponseWriter, r *http.Request) { a.handleGetISCSITarget(w, r) },
		nil,
		func(w http.ResponseWriter, r *http.Request) { a.handleUpdateISCSITarget(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleDeleteISCSITarget(w, r) },
		nil,
	)(w, r)
}

// handleJobOps routes job operations by method
func (a *App) handleJobOps(w http.ResponseWriter, r *http.Request) {
	if strings.HasSuffix(r.URL.Path, "/cancel") {
		if r.Method == http.MethodPost {
			a.handleCancelJob(w, r)
			return
		}
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}

	methodHandler(
		func(w http.ResponseWriter, r *http.Request) { a.handleGetJob(w, r) },
		nil,
		nil,
		nil,
		nil,
	)(w, r)
}

// handleUserOps routes user operations by method
func (a *App) handleUserOps(w http.ResponseWriter, r *http.Request) {
	methodHandler(
		func(w http.ResponseWriter, r *http.Request) { a.handleGetUser(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleCreateUser(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleUpdateUser(w, r) },
		func(w http.ResponseWriter, r *http.Request) { a.handleDeleteUser(w, r) },
		nil,
	)(w, r)
}