package ai

import (
	"context"
	"encoding/json"
	"errors"
	"strings"
	"testing"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgconn"

	"github.com/missionworkforce/missionmatch/internal/platform/scrub"
)

// TestAllowExternalRefusesForbiddenPayload proves the external lane will not carry a payload that still
// holds a private data marker, so a misclassified candidate fact is caught before it leaves the machine.
func TestAllowExternalRefusesForbiddenPayload(t *testing.T) {
	if _, err := AllowExternal("openai", []scrub.Provenance{scrub.ProvenancePublicCache}, scrub.ClassRequirementNormalize, []byte("normalize scope for candidate 11111111-1111-1111-1111-111111111111")); err == nil {
		t.Fatal("a payload with a private data marker must be refused before it can leave for an external backend")
	}
}

// TestAllowExternalRefusesUnknownClass proves the external lane fails closed on any class outside the
// four public classes, for example an attempt to route slate contents.
func TestAllowExternalRefusesUnknownClass(t *testing.T) {
	if _, err := AllowExternal("openai", []scrub.Provenance{scrub.ProvenancePublicCache}, scrub.EgressClass("SLATE_CONTENTS"), []byte("clean public text")); err == nil {
		t.Fatal("a class outside the public allow list must be refused")
	}
}

// TestAllowExternalReturnsAuditMetadataNeverContent proves a permitted call yields the audit metadata the
// orchestrator records: backend, payload class, byte count, and content hash, and never the content.
func TestAllowExternalReturnsAuditMetadataNeverContent(t *testing.T) {
	payload := []byte("Public solicitation notice, analyst support services, clearance intelligence indicated.")
	meta, err := AllowExternal("openai", []scrub.Provenance{scrub.ProvenancePublicCache}, scrub.ClassRequirementNormalize, payload)
	if err != nil {
		t.Fatalf("clean public text under a permitted class must be allowed: %v", err)
	}
	if meta["backend"] != "openai" {
		t.Errorf("expected backend openai, got %v", meta["backend"])
	}
	if meta["payload_class"] != string(scrub.ClassRequirementNormalize) {
		t.Errorf("expected the payload class recorded, got %v", meta["payload_class"])
	}
	if meta["byte_count"] != len(payload) {
		t.Errorf("expected byte_count %d, got %v", len(payload), meta["byte_count"])
	}
	if meta["content_sha256"] != scrub.ContentHash(payload) {
		t.Errorf("expected the content hash recorded, got %v", meta["content_sha256"])
	}
	blob, _ := json.Marshal(meta)
	if strings.Contains(string(blob), "solicitation") || strings.Contains(string(blob), "analyst") {
		t.Fatal("audit metadata must record backend, class, bytes, and hash, never the content itself")
	}
}

// Gate 2: the audit metadata must record the PROVENANCE alongside the class, because the provenance is now
// the primary control and an audit that omits it cannot answer the question an assessor will actually ask,
// which is where the data that left came from.
func TestExternalAuditRecordsProvenance(t *testing.T) {
	meta, err := AllowExternal("openai", []scrub.Provenance{scrub.ProvenancePublicCache}, scrub.ClassRequirementNormalize, []byte("public notice text"))
	if err != nil {
		t.Fatalf("a public payload was refused: %v", err)
	}
	if len(meta["provenance"].([]string)) != 1 || meta["provenance"].([]string)[0] != string(scrub.ProvenancePublicCache) {
		t.Fatalf("the audit metadata does not record the provenance: %v", meta)
	}
	if _, ok := meta["content_sha256"]; !ok {
		t.Fatal("the audit metadata lost its content hash")
	}
	if _, ok := meta["content"]; ok {
		t.Fatal("the audit metadata carries CONTENT, which it must never do")
	}
}

// A tenant sourced payload is refused before any audit metadata is produced, so a caller cannot record a
// call it was not permitted to make.
func TestTenantProvenanceIsRefusedAtTheWrapper(t *testing.T) {
	for _, p := range []scrub.Provenance{scrub.ProvenanceTenantUpload, scrub.ProvenanceTenantRecord} {
		meta, err := AllowExternal("openai", []scrub.Provenance{p}, scrub.ClassRequirementNormalize, []byte("harmless looking text"))
		if err == nil {
			t.Fatalf("provenance %s was allowed to egress", p)
		}
		if meta != nil {
			t.Fatalf("audit metadata was produced for a refused call: %v", meta)
		}
	}
}

// ============================================================================
// THE PERSISTED AUDIT ROW. Added 29 July 2026 closing finding three.
// ============================================================================
//
// The tests above assert the SHAPE OF A MAP. They passed for two days while no row was ever written,
// because the only caller logged the map and persisted nothing. A test that proves metadata is produced is
// not a test that proves it is recorded, and the difference is the whole finding.

// auditDB is a DBTX whose one insert either succeeds or fails, so the fail closed path is proven rather
// than argued. It also CAPTURES the arguments, which is how the never content promise is checked.
type auditDB struct {
	fail     bool
	rows     int
	captured []any
}

func (d *auditDB) Exec(context.Context, string, ...interface{}) (pgconn.CommandTag, error) {
	return pgconn.CommandTag{}, nil
}

func (d *auditDB) Query(context.Context, string, ...interface{}) (pgx.Rows, error) {
	return nil, errors.New("audit tests never Query")
}

func (d *auditDB) QueryRow(_ context.Context, _ string, args ...interface{}) pgx.Row {
	d.rows++
	d.captured = args
	return auditRow{fail: d.fail}
}

type auditRow struct{ fail bool }

func (r auditRow) Scan(...any) error {
	if r.fail {
		return errors.New("audit_logs is unavailable")
	}
	return nil
}

func publicProvs() []scrub.Provenance { return []scrub.Provenance{scrub.ProvenancePublicCache} }

const noticePayload = "Elevator maintenance services. Department: VA. NAICS: 238290."

// AN EXTERNAL CALL THAT CANNOT BE AUDITED MUST NOT HAPPEN. This is the fail closed assertion, and it is the
// reason the gate and the row are one function: a caller that got metadata back and sent anyway would be
// making an unrecorded egress, which is worse than a refused one because a refusal is visible.
func TestExternalEgressIsRefusedWhenItsAuditRowCannotBeWritten(t *testing.T) {
	db := &auditDB{fail: true}
	meta, err := AllowExternalAudited(context.Background(), db, nil, "megamind-gateway",
		publicProvs(), scrub.ClassRequirementNormalize, []byte(noticePayload))
	if err == nil {
		t.Fatal("egress was PERMITTED while its audit row could not be written, so an unrecorded external call is possible")
	}
	if meta != nil {
		t.Error("metadata was returned alongside the refusal, which invites a caller to send anyway")
	}
	if db.rows != 1 {
		t.Errorf("the insert was attempted %d times, want 1: this test would pass while measuring nothing if the audit write were never reached", db.rows)
	}
	if !strings.Contains(err.Error(), "audit") {
		t.Errorf("the refusal does not say the audit was the cause: %v", err)
	}
}

// THE ROW IS WRITTEN, IT CARRIES THE FOUR REQUIRED FIELDS, AND IT CARRIES NO CONTENT.
func TestExternalEgressWritesOneAuditRowCarryingMetadataAndNeverContent(t *testing.T) {
	db := &auditDB{}
	meta, err := AllowExternalAudited(context.Background(), db, nil, "megamind-gateway",
		publicProvs(), scrub.ClassRequirementNormalize, []byte(noticePayload))
	if err != nil {
		t.Fatalf("a permitted payload with a writable audit was refused: %v", err)
	}
	if db.rows != 1 {
		t.Fatalf("wrote %d audit rows, want exactly 1", db.rows)
	}

	// The action and the entity must be findable, because an audit row nobody can query is a row nobody reads.
	var sawAction, sawHash bool
	for _, a := range db.captured {
		s := argString(a)
		if s == ActionExternalInference {
			sawAction = true
		}
		if s == meta["content_sha256"] {
			sawHash = true
		}
		// THE NEVER CONTENT PROMISE. No argument may carry the payload text.
		if strings.Contains(s, "Elevator maintenance") || strings.Contains(s, "238290") {
			t.Error("an audit argument carries the payload CONTENT, which the boundary promises it never does")
		}
	}
	if !sawAction {
		t.Errorf("no argument held the action %q", ActionExternalInference)
	}
	if !sawHash {
		t.Error("no argument held the content hash, so the row cannot be tied to the payload it authorised")
	}

	// The four fields the recorded owner decision requires, by name.
	blob := findJSON(db.captured)
	if blob == nil {
		t.Fatal("no JSON payload was passed to the insert, so the metadata was not recorded at all")
	}
	var got map[string]any
	if err := json.Unmarshal(blob, &got); err != nil {
		t.Fatalf("the recorded metadata is not valid JSON: %v", err)
	}
	for _, field := range []string{"backend", "payload_class", "byte_count", "content_sha256"} {
		if _, ok := got[field]; !ok {
			t.Errorf("the audit row does not record %q", field)
		}
	}
	if got["payload_class"] != string(scrub.ClassRequirementNormalize) {
		t.Errorf("payload_class recorded as %v, want %s", got["payload_class"], scrub.ClassRequirementNormalize)
	}
}

// A REFUSED PAYLOAD WRITES NOTHING. The gate runs first, so a forbidden payload never reaches the audit
// table. Without this, a refusal would still leave a row implying an external call was authorised.
func TestARefusedPayloadWritesNoAuditRow(t *testing.T) {
	db := &auditDB{}
	if _, err := AllowExternalAudited(context.Background(), db, nil, "megamind-gateway",
		[]scrub.Provenance{scrub.ProvenanceTenantUpload}, scrub.ClassRequirementNormalize, []byte(noticePayload)); err == nil {
		t.Fatal("a tenant upload was permitted to the external lane")
	}
	if db.rows != 0 {
		t.Errorf("a refused payload wrote %d audit rows, want 0", db.rows)
	}
}

// WHICH BACKEND ACTUALLY SERVED IT. The gateway falls back to the local runtime on failure, so the served
// model is the only thing that distinguishes a real external call from a failure that became a local one.
func TestOutcomeRowRecordsTheModelThatActuallyServed(t *testing.T) {
	db := &auditDB{}
	if err := RecordExternalOutcome(context.Background(), db, nil, "abc123", "openai:gpt-4o-mini", 412); err != nil {
		t.Fatalf("recording the outcome failed: %v", err)
	}
	if db.rows != 1 {
		t.Fatalf("wrote %d rows, want 1", db.rows)
	}
	blob := findJSON(db.captured)
	if blob == nil {
		t.Fatal("no JSON payload recorded")
	}
	var got map[string]any
	if err := json.Unmarshal(blob, &got); err != nil {
		t.Fatalf("not valid JSON: %v", err)
	}
	if got["served_model"] != "openai:gpt-4o-mini" {
		t.Errorf("served_model recorded as %v, want openai:gpt-4o-mini", got["served_model"])
	}
	if got["content_sha256"] != "abc123" {
		t.Errorf("the outcome row is not tied to the egress row by content hash, got %v", got["content_sha256"])
	}
}

// argString renders an insert argument for inspection, following the pointer that sqlc uses for a nullable
// column. A nil pointer must not be dereferenced, and a non string argument is simply not a string.
func argString(a any) string {
	switch v := a.(type) {
	case string:
		return v
	case *string:
		if v == nil {
			return ""
		}
		return *v
	}
	return ""
}

func findJSON(args []any) []byte {
	for _, a := range args {
		if b, ok := a.([]byte); ok && len(b) > 0 && b[0] == '{' {
			return b
		}
	}
	return nil
}