package main

import (
	"path/filepath"
	"sort"
	"strings"
)

// coreSDKModulePath is the shared Go SDK that carries the canonical proto
// definitions (blockninja.v1, orchestrator.v1, helpdesk.v1) consumed by the
// serving backends. It has no connect server and no RBAC interceptor of its
// own — RBAC is enforced in the repos that actually serve these procedures
// (cms for blockninja.v1, orchestrator for orchestrator.v1), where check 2
// runs against their interceptors. Scanning the SDK in isolation would flag
// every shared procedure as "missing"; that is a not-applicable result, not a
// finding.
const coreSDKModulePath = "git.dev.alexdunmow.com/block/core"

// definitionsOnlyModulePaths are Go modules that carry proto service/rpc
// definitions but serve NONE of them — RBAC is enforced in the repos that
// actually serve the procedures (cms for blockninja.v1, orchestrator for
// orchestrator.v1). Scanning them in isolation would flag every procedure as
// "missing from MethodRoles", a not-applicable result rather than a finding.
//
//   - core: the shared proto SDK.
//   - cli:  the ninja developer CLI (WO-WZ-023). It vendors
//     orchestrator/v1/plugin_registry.proto to generate a CLIENT for the
//     registry; it has no server and no RBAC interceptor.
var definitionsOnlyModulePaths = map[string]bool{
	coreSDKModulePath:                  true,
	"git.dev.alexdunmow.com/block/cli": true,
}

// isDefinitionsOnlySDKTarget reports whether the backend target carries proto
// but serves nothing, so it has neither an RBAC interceptor nor a designated
// serving package prefix. Such a target is out of scope for check 2 — see
// definitionsOnlyModulePaths.
func isDefinitionsOnlySDKTarget(target backendScanTarget) bool {
	if len(target.allowedPackagePrefixes) > 0 {
		return false // a designated serving backend (cms/orchestrator)
	}
	if fileExists(filepath.Join(target.root, "internal/rbac/interceptor.go")) {
		return false // has a serving RBAC interceptor
	}
	modPath, err := readModulePath(target.root)
	if err != nil {
		return false
	}
	return definitionsOnlyModulePaths[modPath]
}

func init() {
	register(Check{
		Seq:   20,
		ID:    "2",
		Title: "RPC methods registered in RBAC interceptor",
		Run: func(ctx *ScanContext, rep *Reporter) {
			protoMethods := make([]string, 0)
			rbacMethods := make(map[string]string)
			protoMethodSet := make(map[string]bool)
			// protoMethodSetAll holds every declared proto procedure (unfiltered
			// by served-surface). Stale detection compares RBAC entries against
			// this full set so an RBAC role for a real-but-unmounted proto method
			// (e.g. orchestrator.v1.DNSService, declared + roled but not served)
			// is not mistaken for a dangling entry.
			protoMethodSetAll := make(map[string]bool)
			requiresRPCDiscovery := false
			var rbacSummaries []rbacTargetSummary
			var definitionsOnlySDKLabels []string

			for _, target := range ctx.backendTargets {
				// The shared proto SDK (core) serves nothing — RBAC is enforced
				// in the consuming repos, where this check runs. Don't fold its
				// procedures into the missing-set; check 2 is not applicable.
				if isDefinitionsOnlySDKTarget(target) {
					definitionsOnlySDKLabels = append(definitionsOnlySDKLabels, target.displayOrRoot())
					continue
				}

				rbacFile := filepath.Join(target.root, "internal/rbac/interceptor.go")
				hasCoreRBAC := fileExists(rbacFile)
				summary := rbacTargetSummary{
					label:        target.displayOrRoot(),
					roleByMethod: make(map[string]string),
				}

				if hasCoreRBAC {
					requiresRPCDiscovery = true
					summary.requiresRPCs = true
					targetProtoMethods, err := extractBufProcedures(target.protoRoot, target.allowedPackagePrefixes...)
					if err != nil {
						rep.Fatal("failed to parse proto files for %s: %v", target.displayOrRoot(), err)
					}
					// Record the FULL declared surface for stale detection, then
					// scope the missing-RBAC check to the procedures this target
					// actually SERVES. A serving backend may carry proto for
					// services it never mounts (for frontend codegen); those are
					// not real RBAC gaps. See extractServedServiceKeys.
					summary.protoMethodsAll = append(summary.protoMethodsAll, targetProtoMethods...)
					for _, pm := range targetProtoMethods {
						protoMethodSetAll[pm] = true
					}
					servedKeys, err := extractServedServiceKeys(target.root)
					if err != nil {
						rep.Fatal("failed to scan served handlers for %s: %v", target.displayOrRoot(), err)
					}
					targetProtoMethods = filterProceduresToServed(targetProtoMethods, servedKeys)
					summary.protoMethods = append(summary.protoMethods, targetProtoMethods...)
					for _, pm := range targetProtoMethods {
						if protoMethodSet[pm] {
							continue
						}
						protoMethodSet[pm] = true
						protoMethods = append(protoMethods, pm)
					}

					targetRBACMethods, err := extractRBACMethodRoles(rbacFile)
					if err != nil {
						rep.Fatal("failed to parse RBAC interceptor for %s: %v", target.displayOrRoot(), err)
					}
					for method, role := range targetRBACMethods {
						rbacMethods[method] = role
						summary.roleByMethod[method] = role
					}
					rbacSummaries = append(rbacSummaries, summary)
					continue
				}

				if len(target.allowedPackagePrefixes) > 0 {
					requiresRPCDiscovery = true
					summary.requiresRPCs = true
				}
				targetProtoMethods, err := extractBufProcedures(target.root)
				if err != nil {
					rep.Fatal("failed to parse proto files for %s: %v", target.displayOrRoot(), err)
				}
				// Same served-surface scoping as the interceptor branch above:
				// keep only procedures whose service this target actually mounts.
				// This is the case the orchestrator hits — its RBAC interceptor
				// lives under backend/ (so hasCoreRBAC is false at this root),
				// and it carries the full blockninja.v1 + helpdesk.v1 proto while
				// serving only orchestrator.v1. The full surface is retained for
				// stale detection.
				summary.protoMethodsAll = append(summary.protoMethodsAll, targetProtoMethods...)
				for _, pm := range targetProtoMethods {
					protoMethodSetAll[pm] = true
				}
				servedKeys, err := extractServedServiceKeys(target.root)
				if err != nil {
					rep.Fatal("failed to scan served handlers for %s: %v", target.displayOrRoot(), err)
				}
				targetProtoMethods = filterProceduresToServed(targetProtoMethods, servedKeys)
				summary.protoMethods = append(summary.protoMethods, targetProtoMethods...)
				for _, pm := range targetProtoMethods {
					if protoMethodSet[pm] {
						continue
					}
					protoMethodSet[pm] = true
					protoMethods = append(protoMethods, pm)
				}

				targetRoleMethods, err := extractPluginRoleMethods(target.root)
				if err != nil {
					rep.Fatal("failed to parse RBAC roles for %s: %v", target.displayOrRoot(), err)
				}
				for method, role := range targetRoleMethods {
					rbacMethods[method] = role
					summary.roleByMethod[method] = role
				}
				rbacSummaries = append(rbacSummaries, summary)
			}

			for _, target := range ctx.pluginTargets {
				summary := rbacTargetSummary{
					label:        target.display,
					roleByMethod: make(map[string]string),
				}
				pluginProtoMethods, err := extractBufProcedures(target.root)
				if err != nil {
					rep.Fatal("failed to parse plugin proto files for %s: %v", target.display, err)
				}
				// Plugins serve every procedure they declare — no served-surface
				// filtering. The full and served sets are identical here.
				summary.protoMethods = append(summary.protoMethods, pluginProtoMethods...)
				summary.protoMethodsAll = append(summary.protoMethodsAll, pluginProtoMethods...)
				for _, pm := range pluginProtoMethods {
					protoMethodSetAll[pm] = true
					if protoMethodSet[pm] {
						continue
					}
					protoMethodSet[pm] = true
					protoMethods = append(protoMethods, pm)
				}

				pluginRoleMethods, err := extractPluginRoleMethods(target.root)
				if err != nil {
					rep.Fatal("failed to parse plugin RBAC roles for %s: %v", target.display, err)
				}
				for method, role := range pluginRoleMethods {
					rbacMethods[method] = role
					summary.roleByMethod[method] = role
				}
				rbacSummaries = append(rbacSummaries, summary)
			}

			if len(protoMethods) == 0 {
				if requiresRPCDiscovery {
					rep.Fatal("no RPC procedures found in proto sources or generated Connect files")
				}
				if len(definitionsOnlySDKLabels) > 0 {
					rep.Skip("%s — definitions-only proto SDK; RBAC enforced in the serving repos (cms/orchestrator), not here", strings.Join(definitionsOnlySDKLabels, ", "))
				} else {
					rep.Skip("no proto-backed RPC procedures found in scanned target(s)")
				}
			} else {
				var missing []string
				for _, m := range protoMethods {
					if isExcludedServiceMethod(m) {
						continue
					}
					if _, ok := rbacMethods[m]; !ok {
						missing = append(missing, m)
					}
				}

				// Stale = an RBAC entry that matches no DECLARED proto method at
				// all (compare against the full surface, not the served subset —
				// a role for a real-but-unmounted proto method is intentional, not
				// dangling).
				var stale []string
				for m := range rbacMethods {
					if !protoMethodSetAll[m] {
						if isExcludedServiceMethod(m) {
							continue
						}
						stale = append(stale, m)
					}
				}
				sort.Strings(stale)
				for i := range rbacSummaries {
					summary := &rbacSummaries[i]
					for _, method := range summary.protoMethods {
						if isExcludedServiceMethod(method) {
							continue
						}
						if _, ok := summary.roleByMethod[method]; !ok {
							summary.missingCount++
						}
					}
					for method := range summary.roleByMethod {
						if isExcludedServiceMethod(method) {
							continue
						}
						// Compare against the full declared surface (see the
						// global stale note above), not the served subset.
						if !containsString(summary.protoMethodsAll, method) {
							summary.staleCount++
						}
					}
				}

				for _, summary := range rbacSummaries {
					if len(summary.protoMethods) == 0 {
						if summary.requiresRPCs {
							rep.Fail("%s — no RPC procedures found", summary.label)
						} else {
							rep.OK("%s — no proto-backed RPC procedures", summary.label)
						}
						continue
					}
					rep.OK("%s — %d RPC methods discovered", summary.label, len(summary.protoMethods))
					if summary.missingCount > 0 {
						rep.Findingf("missing RBAC entries: %d", summary.missingCount)
					}
					if summary.staleCount > 0 {
						rep.Findingf("stale RBAC entries: %d", summary.staleCount)
					}
				}

				if len(missing) > 0 {
					rep.Fail("%d RPC method(s) NOT in MethodRoles (will get permission_denied)", len(missing))
					for _, m := range missing {
						rep.Findingf("- %s", m)
					}
				}

				if len(stale) > 0 {
					rep.Warn("%d RBAC entries have no matching proto method (stale?)", len(stale))
					for _, m := range stale {
						rep.Findingf("- %s", m)
					}
				}

				if len(missing) == 0 && len(stale) == 0 {
					rep.OK("All %d RPC methods are registered in MethodRoles", len(protoMethods))
				} else if len(missing) == 0 {
					rep.OK("All %d RPC methods are registered (but %d stale entries exist)", len(protoMethods), len(stale))
				}
			}
		},
	})
}