package main

import (
	"encoding/json"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func TestClusterFindingsAgreementAndTolerance(t *testing.T) {
	models := []modelFindings{
		{Model: "m1", Verdict: "Blocking issues found", Findings: []outFinding{
			{Lens: "security", File: "a.go", Line: 10, Severity: "high", Title: "auth bypass"},
			{Lens: "perf", File: "b.go", Line: 5, Severity: "trivial", Title: "tiny nit"},
		}},
		{Model: "m2", Verdict: "Minor issues", Findings: []outFinding{
			{Lens: "security", File: "a.go", Line: 11, Severity: "critical", Title: "auth bypass (crit)"}, // within tolerance of a.go:10
		}},
		{Model: "m3", Verdict: "Minor issues", Findings: []outFinding{
			{Lens: "correctness", File: "a.go", Line: 10, Severity: "medium", Title: "auth bypass"},
		}},
	}
	clusters := clusterFindings(models)
	if len(clusters) != 2 {
		t.Fatalf("want 2 clusters (a.go:10±, b.go:5), got %d: %+v", len(clusters), clusters)
	}
	// First cluster (highest agreement) is the a.go auth one: 3 models, severity
	// escalated to critical, representative line the smallest (10).
	c := clusters[0]
	if len(c.models) != 3 {
		t.Errorf("want 3 models on the top cluster, got %d", len(c.models))
	}
	if c.severity != "critical" {
		t.Errorf("want escalated severity critical, got %q", c.severity)
	}
	if c.line != 10 {
		t.Errorf("want representative line 10, got %d", c.line)
	}
	if !c.lenses["security"] || !c.lenses["correctness"] {
		t.Errorf("want union of lenses, got %v", c.lenses)
	}
}

func TestRenderConsensusFoldsSingleModelNits(t *testing.T) {
	models := []modelFindings{
		{Model: "m1", Provider: "p", Verdict: "Blocking issues found", Markdown: "m1 detail", Findings: []outFinding{
			{Lens: "security", File: "a.go", Line: 10, Severity: "high", Title: "auth bypass"},
			{Lens: "perf", File: "b.go", Line: 5, Severity: "trivial", Title: "tiny nit"},
		}},
		{Model: "m2", Provider: "p", Verdict: "Minor issues", Markdown: "m2 detail", Findings: []outFinding{
			{Lens: "security", File: "a.go", Line: 10, Severity: "high", Title: "auth bypass"},
		}},
	}
	out := renderConsensus(models, clusterFindings(models))
	// Headline table: the agreed finding with a 2/2 badge.
	if !strings.Contains(out, "2/2") {
		t.Errorf("expected a 2/2 agreement badge in headline:\n%s", out)
	}
	if !strings.Contains(out, "auth bypass") || !strings.Contains(out, "a.go:10") {
		t.Errorf("headline missing the consensus finding:\n%s", out)
	}
	// The lone trivial finding is folded, not in the headline table.
	if !strings.Contains(out, "single-model finding") {
		t.Errorf("expected a folded single-model section:\n%s", out)
	}
	// Per-model detail is preserved (folded).
	if !strings.Contains(out, "m1 detail") || !strings.Contains(out, "m2 detail") {
		t.Errorf("per-model detail not preserved:\n%s", out)
	}
}

func TestRenderConsensusHighSeverityLoneFindingStaysHeadline(t *testing.T) {
	// A single model, single critical finding must still surface in the headline
	// (not be folded as "low confidence").
	models := []modelFindings{
		{Model: "solo", Verdict: "Blocking issues found", Markdown: "x", Findings: []outFinding{
			{Lens: "security", File: "a.go", Line: 1, Severity: "critical", Title: "rce"},
		}},
	}
	out := renderConsensus(models, clusterFindings(models))
	headline := out
	if i := strings.Index(out, "single-model finding"); i >= 0 {
		headline = out[:i]
	}
	if !strings.Contains(headline, "rce") {
		t.Errorf("lone critical should be in the headline, not folded:\n%s", out)
	}
}

func TestClusterSlidingWindowMergesChain(t *testing.T) {
	// Findings at 10, 13, 16 (each 3 apart) from three models must merge into ONE
	// cluster — the window slides with the span instead of anchoring at line 10.
	models := []modelFindings{
		{Model: "m1", Findings: []outFinding{{Lens: "x", File: "a.go", Line: 10, Severity: "medium", Title: "t"}}},
		{Model: "m2", Findings: []outFinding{{Lens: "x", File: "a.go", Line: 13, Severity: "medium", Title: "t"}}},
		{Model: "m3", Findings: []outFinding{{Lens: "x", File: "a.go", Line: 16, Severity: "medium", Title: "t"}}},
	}
	clusters := clusterFindings(models)
	if len(clusters) != 1 {
		t.Fatalf("chain 10/13/16 should merge into 1 cluster, got %d", len(clusters))
	}
	if len(clusters[0].models) != 3 {
		t.Errorf("want 3 models in the merged cluster, got %d", len(clusters[0].models))
	}
}

func TestRenderConsensusExcludesErroredFromDenominator(t *testing.T) {
	models := []modelFindings{
		{Model: "m1", Verdict: "Minor issues", Markdown: "a", Findings: []outFinding{
			{Lens: "security", File: "a.go", Line: 9, Severity: "medium", Title: "leak"}}},
		{Model: "m2", Verdict: "Minor issues", Markdown: "b", Findings: []outFinding{
			{Lens: "security", File: "a.go", Line: 9, Severity: "medium", Title: "leak"}}},
		{Model: "broken", Verdict: "reviewer failed", Errored: true, Markdown: "boom"},
	}
	out := renderConsensus(models, clusterFindings(models))
	// Denominator is the 2 effective models, not 3; the failure is noted.
	if !strings.Contains(out, "2/2") {
		t.Errorf("errored model must be excluded from the denominator (want 2/2):\n%s", out)
	}
	if !strings.Contains(out, "1 failed") {
		t.Errorf("expected a '1 failed' note:\n%s", out)
	}
	if !strings.Contains(out, "reviewer failed") {
		t.Errorf("errored model should still appear (folded) as failed:\n%s", out)
	}
}

func TestRenderConsensusLoneHighFolds(t *testing.T) {
	// A single-model HIGH (not critical) folds — only consensus or a lone CRITICAL
	// earns the headline, so a lone Blocking-lens finding doesn't reintroduce noise.
	models := []modelFindings{
		{Model: "solo", Verdict: "Blocking issues found", Markdown: "x", Findings: []outFinding{
			{Lens: "security", File: "a.go", Line: 1, Severity: "high", Title: "maybe-bug"}}},
	}
	out := renderConsensus(models, clusterFindings(models))
	head := out
	if i := strings.Index(out, "single-model finding"); i >= 0 {
		head = out[:i]
	}
	if strings.Contains(head, "maybe-bug") {
		t.Errorf("a lone HIGH should fold, not headline:\n%s", out)
	}
}

func TestWriteAndConsolidateRoundTrip(t *testing.T) {
	dir := t.TempDir()

	// Two model artifacts on disk.
	write := func(name string, mf modelFindings) {
		data, _ := json.Marshal(mf)
		if err := os.WriteFile(filepath.Join(dir, name), data, 0o644); err != nil {
			t.Fatal(err)
		}
	}
	write("m1.json", modelFindings{Model: "m1", Provider: "ollama", Verdict: "Minor issues", Markdown: "md1",
		Findings: []outFinding{{Lens: "security", File: "x.go", Line: 3, Severity: "medium", Title: "leak"}}})
	write("m2.json", modelFindings{Model: "m2", Provider: "ollama", Verdict: "Minor issues", Markdown: "md2",
		Findings: []outFinding{{Lens: "security", File: "x.go", Line: 3, Severity: "high", Title: "leak"}}})
	// A junk file must be skipped, not crash consolidation.
	if err := os.WriteFile(filepath.Join(dir, "notes.txt"), []byte("ignore me"), 0o644); err != nil {
		t.Fatal(err)
	}

	t.Setenv("GADFLY_CONSOLIDATE_DIR", dir)
	// runConsolidate prints to stdout; capture it.
	out := captureStdout(t, func() {
		if err := runConsolidate(); err != nil {
			t.Fatalf("runConsolidate: %v", err)
		}
	})
	if !strings.HasPrefix(strings.TrimSpace(out), consensusMarker) {
		t.Errorf("consolidated output must lead with the marker:\n%s", out)
	}
	if !strings.Contains(out, "2/2") || !strings.Contains(out, "x.go:3") {
		t.Errorf("expected the agreed x.go:3 finding at 2/2:\n%s", out)
	}
}

func TestRunConsolidateEmptyDirErrors(t *testing.T) {
	t.Setenv("GADFLY_CONSOLIDATE_DIR", t.TempDir())
	if err := runConsolidate(); err == nil {
		t.Error("want an error for an empty consolidate dir (entrypoint falls back)")
	}
}

// captureStdout redirects os.Stdout for the duration of fn and returns what was
// written.
func captureStdout(t *testing.T, fn func()) string {
	t.Helper()
	orig := os.Stdout
	r, w, err := os.Pipe()
	if err != nil {
		t.Fatal(err)
	}
	os.Stdout = w
	defer func() { os.Stdout = orig }() // restore even if fn panics
	done := make(chan string)
	go func() {
		var sb strings.Builder
		buf := make([]byte, 4096)
		for {
			n, err := r.Read(buf)
			if n > 0 {
				sb.Write(buf[:n])
			}
			if err != nil {
				break
			}
		}
		r.Close()
		done <- sb.String()
	}()
	fn()
	w.Close()
	return <-done
}