package contracts_test

import (
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/santhosh-tekuri/jsonschema/v6"
)

const v1Dir = "upstream/v1"
const v1Base = "https://go-sip.local/contracts/v1/"

type offlineLoader struct{}

func (offlineLoader) Load(url string) (any, error) {
	return nil, fmt.Errorf("schema is not in the immutable local bundle: %s", url)
}

func compileV1(t *testing.T, name string) *jsonschema.Schema {
	t.Helper()
	compiler := jsonschema.NewCompiler()
	compiler.AssertFormat()
	compiler.UseLoader(offlineLoader{})
	paths, err := filepath.Glob(filepath.Join(v1Dir, "*.schema.json"))
	if err != nil || len(paths) == 0 {
		t.Fatalf("contract bundle missing: %v", err)
	}
	for _, path := range paths {
		var schema any
		if err := json.Unmarshal(readV1(t, path), &schema); err != nil {
			t.Fatal(err)
		}
		if err := compiler.AddResource(v1Base+filepath.Base(path), schema); err != nil {
			t.Fatal(err)
		}
	}
	schema, err := compiler.Compile(v1Base + name)
	if err != nil {
		t.Fatal(err)
	}
	return schema
}

func readV1(t *testing.T, path string) []byte {
	t.Helper()
	raw, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	return raw
}

func objectV1(t *testing.T, path string) map[string]any {
	t.Helper()
	var value map[string]any
	if err := json.Unmarshal(readV1(t, path), &value); err != nil {
		t.Fatal(err)
	}
	return value
}

func TestV1BundleFixtures(t *testing.T) {
	for _, name := range []string{"mq.schema.json", "event-payloads.schema.json", "dispatcher-config.schema.json"} {
		t.Run(name, func(t *testing.T) { compileV1(t, name) })
	}
	var cases []struct {
		File   string `json:"file"`
		Schema string `json:"schema"`
		Valid  bool   `json:"valid"`
	}
	if err := json.Unmarshal(readV1(t, filepath.Join(v1Dir, "fixtures.json")), &cases); err != nil {
		t.Fatal(err)
	}
	if len(cases) < 16 {
		t.Fatal("missing bounded positive and negative message/config fixtures")
	}
	for _, tc := range cases {
		t.Run(tc.File, func(t *testing.T) {
			schema := compileV1(t, tc.Schema)
			value := objectV1(t, filepath.Join(v1Dir, tc.File))
			err := schema.Validate(value)
			if (err == nil) != tc.Valid {
				t.Fatalf("valid=%v, validation=%v", tc.Valid, err)
			}
		})
	}
}

func TestV1ExecuteIdentityAndTenantConstraints(t *testing.T) {
	schema := compileV1(t, "mq.schema.json")
	for _, tc := range []struct {
		name string
		edit func(map[string]any)
	}{
		{"missing dispatcher", func(m map[string]any) { delete(m, "dispatcher_id") }},
		{"non UUID dispatcher", func(m map[string]any) { m["dispatcher_id"] = "dispatcher-a" }},
		{"uppercase dispatcher", func(m map[string]any) { m["dispatcher_id"] = strings.ToUpper(m["dispatcher_id"].(string)) }},
		{"wildcard tenant", func(m map[string]any) { m["tenant_key"] = "tenant.#" }},
		{"old version", func(m map[string]any) { m["schema_version"] = "1.0" }},
		{"extra root", func(m map[string]any) { m["metadata"] = map[string]any{} }},
		{"extra payload", func(m map[string]any) { m["payload"].(map[string]any)["mode"] = "full_ai" }},
	} {
		t.Run(tc.name, func(t *testing.T) {
			value := objectV1(t, filepath.Join(v1Dir, "examples/call-execute.json"))
			tc.edit(value)
			if err := schema.Validate(value); err == nil {
				t.Fatal("invalid envelope accepted")
			}
		})
	}
}

func TestV1ResponseCorrelationAndResultBranches(t *testing.T) {
	schema := compileV1(t, "mq.schema.json")
	for _, tc := range []struct {
		name string
		edit func(map[string]any)
	}{
		{"missing correlation", func(m map[string]any) { delete(m, "correlation_id") }},
		{"wrong result", func(m map[string]any) { m["status"] = "rejected"; m["reason_code"] = "ok" }},
		{"response deadline", func(m map[string]any) { m["not_after"] = "2026-09-21T00:00:30Z" }},
		{"missing command ID", func(m map[string]any) { delete(m["payload"].(map[string]any), "command_id") }},
		{"extra result", func(m map[string]any) { m["payload"].(map[string]any)["raw"] = map[string]any{} }},
	} {
		t.Run(tc.name, func(t *testing.T) {
			value := objectV1(t, filepath.Join(v1Dir, "examples/command-query-result.json"))
			tc.edit(value)
			if err := schema.Validate(value); err == nil {
				t.Fatal("invalid query response accepted")
			}
		})
	}
}

func TestV1UploadIsAFactNotASaaSHandshake(t *testing.T) {
	schema := compileV1(t, "mq.schema.json")
	for _, field := range []string{"oss_id", "verified", "token", "upload_url", "access_key_secret"} {
		t.Run(field, func(t *testing.T) {
			value := objectV1(t, filepath.Join(v1Dir, "examples/event-recording-uploaded.json"))
			value["payload"].(map[string]any)[field] = "not-a-real-value"
			if err := schema.Validate(value); err == nil {
				t.Fatal("uploaded fact accepted a credential or SaaS processing claim")
			}
		})
	}
	for _, kind := range []string{"recording.upload-session.request", "recording.upload-session.result", "recording.complete", "recording.verified"} {
		if strings.Contains(string(readV1(t, filepath.Join(v1Dir, "mq.schema.json"))), `"`+kind+`"`) {
			t.Errorf("removed upload handshake is still in the published schema: %s", kind)
		}
	}
}

func TestV1DispatcherConfigDoesNotAcceptSecretsOrTTLOverride(t *testing.T) {
	schema := compileV1(t, "dispatcher-config.schema.json")
	for _, field := range []string{"access_key_id", "access_key_secret", "grant_ttl_seconds", "token"} {
		t.Run(field, func(t *testing.T) {
			value := objectV1(t, filepath.Join(v1Dir, "examples/dispatcher-config.json"))
			value["oss"].(map[string]any)[field] = "not-a-real-value"
			if err := schema.Validate(value); err == nil {
				t.Fatal("unexpected secret/override field accepted")
			}
		})
	}
}

func TestV1ManifestPinsEveryBundleFile(t *testing.T) {
	var manifest struct {
		Version string            `json:"version"`
		Source  string            `json:"source"`
		Files   map[string]string `json:"files"`
	}
	if err := json.Unmarshal(readV1(t, filepath.Join(v1Dir, "manifest.json")), &manifest); err != nil {
		t.Fatal(err)
	}
	if manifest.Version != "v1" || manifest.Source != "project-development-v1" || len(manifest.Files) == 0 {
		t.Fatal("invalid project-local provenance")
	}
	err := filepath.WalkDir(v1Dir, func(path string, entry os.DirEntry, err error) error {
		if err != nil || entry.IsDir() {
			return err
		}
		rel, err := filepath.Rel(v1Dir, path)
		if err != nil || rel == "manifest.json" {
			return err
		}
		actual := sha256.Sum256(readV1(t, path))
		if manifest.Files[filepath.ToSlash(rel)] != hex.EncodeToString(actual[:]) {
			t.Errorf("missing/incorrect manifest hash: %s", rel)
		}
		return nil
	})
	if err != nil {
		t.Fatal(err)
	}
	for rel := range manifest.Files {
		if !filepath.IsLocal(rel) {
			t.Errorf("non-local manifest entry: %s", rel)
			continue
		}
		if _, err := os.Stat(filepath.Join(v1Dir, rel)); err != nil {
			t.Error(err)
		}
	}
}