// Package lexicon_meta_cover holds the Cover lexicon firewall (REQ-055,
// D-088) — the 4th lexicon meta-test.
//
// It is a NEW sibling meta-test created in v0.7 P1 that MIRRORS the v0.6
// web firewall (lexicon_meta_web/lexicon_meta_web_test.go, package
// lexicon_meta_web) but scans the Cover module surface (x/cover/**/*.go)
// for BOTH the 10 project-wide banned terms (lexicon.FindBannedTerm) AND
// the 4 Cover-specific banned terms (lexicon.FindCoverBannedTerm — D-088).
// It uses the SAME lexicon.FindBannedTerm + lexicon.FindCoverBannedTerm
// (word-boundary, case-insensitive) — NO detection reimplementation — so
// the four firewalls (x/*.go project-wide, docs, web, cover) share a
// single source of truth for the banned terms. The Cover-specific 4 terms
// (insurance, premium, claim, policy — assembled from fragments by
// lexicon.CoverBannedTerms) are the Cover-module superset layer: the
// project-wide 10 terms ALSO apply to x/cover; this firewall adds the 4
// Cover-specific terms on top.
//
// Placement: this file lives in lexicon_meta_cover/ (a subdirectory of the
// repo root) because Go does not permit two distinct packages in the same
// directory; the v0.2 firewall is package lexicon_meta at the repo root,
// the v0.3 firewall is package lexicon_meta_docs in lexicon_meta_docs/,
// and the v0.6 firewall is package lexicon_meta_web in lexicon_meta_web/.
// The invocation `go test ./lexicon_meta_cover/...` (PLANS v0.7 P1)
// resolves to this package. Run via `go test ./...` from the repo root.
//
// G-013 walk-coverage: TestLexiconMetaCoverWalkCoverage injects synthetic
// banned-term .go files into a temp x/cover/ subtree and asserts the walk
// FINDS them — one for a project-wide term, one for a Cover-specific term.
// This closes the "silently scans nothing and reports green" failure mode
// that the G-009 self-test table (detection) alone does not cover.
//
// G-014 self-test drift: the self-test tables reuse
// lexicon.SyntheticBannedStrings() (project-wide) +
// lexicon.SyntheticCoverBannedStrings() (Cover-specific) — the single
// sources of truth shared with the other three meta-tests.
//
// G-024: this test file stays stdlib + lexicon-only (no cosmos-sdk import).
package lexicon_meta_cover

import (
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"testing"

	"github.com/oy/openyield/lexicon"
)

// repoRoot returns the absolute path to the repo root by walking up from
// this test file (the test lives at <repoRoot>/lexicon_meta_cover/).
func repoRoot(t *testing.T) string {
	t.Helper()
	_, file, _, ok := runtime.Caller(0)
	if !ok {
		t.Fatal("runtime.Caller failed")
	}
	// file = .../oy/lexicon_meta_cover/lexicon_meta_cover_test.go
	// repo root = filepath.Dir(filepath.Dir(file))
	return filepath.Dir(filepath.Dir(file))
}

// coverRoot returns the absolute path to the repo's x/cover directory.
func coverRoot(t *testing.T) string {
	t.Helper()
	return filepath.Join(repoRoot(t), "x", "cover")
}

// thisFile returns the absolute path of this meta-test file (to exclude it
// from its own scan — it references banned terms via the lexicon package,
// whose source assembles terms from fragments, so no banned-term literal
// appears in the firewall's own code).
func thisFile(t *testing.T) string {
	t.Helper()
	_, file, _, ok := runtime.Caller(0)
	if !ok {
		t.Fatal("runtime.Caller failed")
	}
	return file
}

// isCoverTarget reports whether path (relative to repo root) is a .go file
// under x/cover/ (production + test). Non-.go files under x/cover/ are
// skipped.
func isCoverTarget(rel string) bool {
	prefix := strings.Join([]string{"x", "cover", ""}, string(filepath.Separator))
	if !strings.HasPrefix(rel, prefix) {
		return false
	}
	return strings.HasSuffix(rel, ".go")
}

// TestLexiconMetaCoverNoBannedTerms is the Cover firewall (D-088). It walks
// x/cover/**/*.go (production + test), reads each file's source, and
// asserts no banned term (project-wide OR Cover-specific) is present
// (word-boundary, case-insensitive). Excludes this test file itself
// (self-exclusion via runtime.Caller(0) — though this file lives outside
// x/cover/, the exclusion is belt-and-suspenders in case the walk root is
// ever broadened).
//
// Passes at P1 with the x/cover module lexicon-clean by construction. The
// x/cover/types/types_test.go per-package lexicon assertion
// (TestLexiconNoBannedTermsInCover) is the in-module firewall; this
// meta-test is the repo-wide Cover firewall (run via `go test ./...`).
func TestLexiconMetaCoverNoBannedTerms(t *testing.T) {
	root := coverRoot(t)
	this := thisFile(t)
	hits := []string{}
	err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if info.IsDir() {
			// Skip the walk-coverage fixture dir (G-013):
			// TestLexiconMetaCoverWalkCoverage creates
			// x/cover/.lexicon_fixture/ with synthetic banned-term .go
			// files. Those fixtures are test artifacts, NOT production
			// code; skip the dir to avoid a self-trip if cleanup is
			// delayed.
			if info.Name() == ".lexicon_fixture" {
				return filepath.SkipDir
			}
			return nil
		}
		if !strings.HasSuffix(path, ".go") {
			return nil
		}
		// Self-exclusion: skip this meta-test file (belt-and-suspenders;
		// this file lives outside x/cover/ so the walk would not reach it
		// anyway, but the exclusion is robust to a future walk-root change).
		if path == this {
			return nil
		}
		bz, rerr := os.ReadFile(path)
		if rerr != nil {
			return rerr
		}
		src := string(bz)
		// Project-wide 10 terms.
		if found, ok := lexicon.FindBannedTerm(src); ok {
			rel, _ := filepath.Rel(root, path)
			hits = append(hits, rel+" contains project-wide banned term "+found)
		}
		// Cover-specific 4 terms.
		if found, ok := lexicon.FindCoverBannedTerm(src); ok {
			rel, _ := filepath.Rel(root, path)
			hits = append(hits, rel+" contains Cover-specific banned term "+found)
		}
		return nil
	})
	if err != nil {
		t.Fatalf("walk: %v", err)
	}
	if len(hits) > 0 {
		t.Errorf("REQ-055/D-088 Cover lexicon firewall violations:\n  %s",
			strings.Join(hits, "\n  "))
	}
}

// TestLexiconMetaCoverSelfTestTable (G-009 for cover) is the firewall's own
// detection-coverage guard. Each synthetic string embeds exactly one
// banned term in a plausible sentence context and is asserted to trigger
// detection, so the firewall's detection logic is durably verified — if
// detection ever breaks, this test fails before the firewall silently
// passes a real violation in a Cover source file.
//
// This test exercises BOTH the project-wide terms (lexicon.SyntheticBannedStrings
// + lexicon.FindBannedTerm) AND the Cover-specific terms
// (lexicon.SyntheticCoverBannedStrings + lexicon.FindCoverBannedTerm),
// so both layers of the Cover firewall are durably verified.
func TestLexiconMetaCoverSelfTestTable(t *testing.T) {
	// Project-wide layer.
	terms := lexicon.BannedTerms()
	if len(terms) != 10 {
		t.Fatalf("BannedTerms() len = %d, want 10", len(terms))
	}
	synthetic := lexicon.SyntheticBannedStrings()
	if len(synthetic) != len(terms) {
		t.Fatalf("SyntheticBannedStrings() len = %d, want %d", len(synthetic), len(terms))
	}
	for i, s := range synthetic {
		found, ok := lexicon.FindBannedTerm(s)
		if !ok {
			t.Errorf("G-009 cover self-test (project-wide) [%d]: synthetic string did not trigger detection: %q", i, s)
			continue
		}
		if found != terms[i] {
			t.Errorf("G-009 cover self-test (project-wide) [%d]: detected %q, want %q (in %q)", i, found, terms[i], s)
		}
	}

	// Cover-specific layer.
	coverTerms := lexicon.CoverBannedTerms()
	if len(coverTerms) != 4 {
		t.Fatalf("CoverBannedTerms() len = %d, want 4 (D-088)", len(coverTerms))
	}
	coverSynthetic := lexicon.SyntheticCoverBannedStrings()
	if len(coverSynthetic) != len(coverTerms) {
		t.Fatalf("SyntheticCoverBannedStrings() len = %d, want %d (must match CoverBannedTerms())", len(coverSynthetic), len(coverTerms))
	}
	for i, s := range coverSynthetic {
		found, ok := lexicon.FindCoverBannedTerm(s)
		if !ok {
			t.Errorf("G-009 cover self-test (Cover-specific) [%d]: synthetic string did not trigger detection: %q", i, s)
			continue
		}
		if found != coverTerms[i] {
			t.Errorf("G-009 cover self-test (Cover-specific) [%d]: detected %q, want %q (in %q)", i, found, coverTerms[i], s)
		}
	}
}

// TestLexiconMetaCoverBannedTermsCount asserts exactly 10 project-wide
// banned terms + 4 Cover-specific banned terms are configured (locked-const
// for the firewall's scope). Derived from lexicon.BannedTerms() +
// lexicon.CoverBannedTerms() — the single sources — so a count change
// breaks the firewalls (G-014 drift prevention).
func TestLexiconMetaCoverBannedTermsCount(t *testing.T) {
	terms := lexicon.BannedTerms()
	if len(terms) != 10 {
		t.Errorf("BannedTerms() len = %d, want 10 (REQ-012)", len(terms))
	}
	coverTerms := lexicon.CoverBannedTerms()
	if len(coverTerms) != 4 {
		t.Errorf("CoverBannedTerms() len = %d, want 4 (D-088)", len(coverTerms))
	}
	seen := map[string]bool{}
	for _, tr := range terms {
		if seen[tr] {
			t.Errorf("duplicate project-wide banned term %q", tr)
		}
		seen[tr] = true
	}
	for _, tr := range coverTerms {
		if seen[tr] {
			t.Errorf("Cover-specific banned term %q duplicates a project-wide term", tr)
		}
		seen[tr] = true
	}
}

// TestLexiconMetaCoverNoFalsePositiveOnClaimant asserts the field name
// "ClaimantReachID" (used by types.CoverCall) does NOT trigger the
// Cover-specific banned term that looks like a substring of "Claimant"
// (word-boundary matching must not match substrings of identifiers). This
// is the regression firewall for the word-boundary detection design on the
// Cover-specific layer — mirrors the project-wide
// TestLexiconMetaNoFalsePositiveOnOpenYield.
func TestLexiconMetaCoverNoFalsePositiveOnClaimant(t *testing.T) {
	cases := []string{
		"ClaimantReachID",
		"ClaimantReachID string",
		"the ClaimantReachID field",
		"c.ClaimantReachID",
	}
	for _, s := range cases {
		if _, ok := lexicon.FindCoverBannedTerm(s); ok {
			t.Errorf("false positive: %q triggered a Cover-specific banned term (word-boundary must avoid this)", s)
		}
	}
}

// TestLexiconMetaCoverWalkCoverage (G-013) is the walk-coverage firewall
// for the Cover meta-test. The G-009 self-test table (above) verifies
// DETECTION (FindBannedTerm / FindCoverBannedTerm on synthetic strings)
// but NOT the WALK (which files are scanned). A walk bug — e.g. wrong path
// prefix, missing x/cover/ recursion — would silently scan nothing and
// report green on zero files. This test closes that gap by injecting
// synthetic banned-term .go files into a fixture dir under the real
// x/cover/ path the walk scans and asserting the walk FINDS them — one
// fixture for a project-wide term, one for a Cover-specific term.
//
// The fixtures are created under x/cover/.lexicon_fixture/ (a real x/cover/
// subtree the walk reaches) and removed via defer so they never leak into
// the repo. If the walk logic misses either fixture, this test fails loudly
// instead of letting a broken walk pass the firewall green on zero files
// scanned.
func TestLexiconMetaCoverWalkCoverage(t *testing.T) {
	root := coverRoot(t)

	// Build synthetic banned terms from fragments so THIS file does not
	// contain banned-term literals.
	terms := lexicon.BannedTerms()
	if len(terms) == 0 {
		t.Fatal("BannedTerms() returned no terms — cannot run walk-coverage")
	}
	coverTerms := lexicon.CoverBannedTerms()
	if len(coverTerms) == 0 {
		t.Fatal("CoverBannedTerms() returned no terms — cannot run walk-coverage")
	}
	// Project-wide fixture: use the first banned term ("bank") reassembled.
	pwTerm := terms[0][:2] + terms[0][2:]
	// Cover-specific fixture: use the first Cover term reassembled.
	coverTerm := coverTerms[0][:len(coverTerms[0])/2] + coverTerms[0][len(coverTerms[0])/2:]

	fixtureDir := filepath.Join(root, ".lexicon_fixture")
	if err := os.MkdirAll(fixtureDir, 0o755); err != nil {
		t.Fatalf("mkdir fixture: %v", err)
	}
	defer os.RemoveAll(fixtureDir)

	// Project-wide fixture .go file.
	pwFixture := filepath.Join(fixtureDir, "bad_pw_fixture.go")
	pwContent := []byte("// fixture\n// this file contains a project-wide banned term: " + pwTerm + "\npackage lexicon_fixture\n")
	if err := os.WriteFile(pwFixture, pwContent, 0o644); err != nil {
		t.Fatalf("write pw fixture: %v", err)
	}
	// Cover-specific fixture .go file.
	coverFixture := filepath.Join(fixtureDir, "bad_cover_fixture.go")
	coverContent := []byte("// fixture\n// this file contains a Cover-specific banned term: " + coverTerm + "\npackage lexicon_fixture\n")
	if err := os.WriteFile(coverFixture, coverContent, 0o644); err != nil {
		t.Fatalf("write cover fixture: %v", err)
	}

	// Run the SAME walk logic as TestLexiconMetaCoverNoBannedTerms and
	// assert it FINDS both fixtures' banned terms. A walk that returns zero
	// hits here proves the walk logic is broken.
	pwHits := []string{}
	coverHits := []string{}
	err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if info.IsDir() {
			return nil
		}
		if !strings.HasSuffix(path, ".go") {
			return nil
		}
		bz, rerr := os.ReadFile(path)
		if rerr != nil {
			return rerr
		}
		src := string(bz)
		if found, ok := lexicon.FindBannedTerm(src); ok {
			rel, _ := filepath.Rel(root, path)
			pwHits = append(pwHits, rel+":"+found)
		}
		if found, ok := lexicon.FindCoverBannedTerm(src); ok {
			rel, _ := filepath.Rel(root, path)
			coverHits = append(coverHits, rel+":"+found)
		}
		return nil
	})
	if err != nil {
		t.Fatalf("walk: %v", err)
	}

	// Assert the project-wide fixture was found.
	foundPW := false
	for _, h := range pwHits {
		if strings.Contains(h, "bad_pw_fixture.go") && strings.Contains(h, pwTerm) {
			foundPW = true
			break
		}
	}
	if !foundPW {
		t.Errorf("G-013 walk-coverage (project-wide): the walk did NOT find the synthetic project-wide banned-term fixture at %s — the Cover firewall walk logic is broken (it would silently scan nothing and report green). pwHits=%v", pwFixture, pwHits)
	}

	// Assert the Cover-specific fixture was found.
	foundCover := false
	for _, h := range coverHits {
		if strings.Contains(h, "bad_cover_fixture.go") && strings.Contains(h, coverTerm) {
			foundCover = true
			break
		}
	}
	if !foundCover {
		t.Errorf("G-013 walk-coverage (Cover-specific): the walk did NOT find the synthetic Cover-specific banned-term fixture at %s — the Cover firewall walk logic is broken. coverHits=%v", coverFixture, coverHits)
	}
}