package materializer

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

// TestMaterializeAll_RoundTrip writes a fixture source jsonl, runs the
// materializer, and checks every contract: receipt, output rows,
// idempotency on second run.
func TestMaterializeAll_RoundTrip(t *testing.T) {
	root := t.TempDir()
	mustWriteFixture(t, root, "data/_kb/distilled_facts.jsonl",
		`{"run_id":"r1","source_label":"lab-a","created_at":"2026-04-26T00:00:00Z","extractor":"qwen3.5:latest","text":"first"}
{"run_id":"r2","source_label":"lab-b","created_at":"2026-04-26T01:00:00Z","extractor":"qwen3.5:latest","text":"second"}`)

	transforms := []TransformDef{
		{SourceFileRelPath: "data/_kb/distilled_facts.jsonl", Transform: extractorTransform},
	}

	first, err := MaterializeAll(MaterializeOptions{
		Root:       root,
		Transforms: transforms,
		RecordedAt: "2026-05-02T00:00:00Z",
	})
	if err != nil {
		t.Fatalf("first run: %v", err)
	}
	if !first.Receipt.ValidationPass {
		t.Errorf("first run should pass validation. errors=%v warnings=%v", first.Receipt.Errors, first.Receipt.Warnings)
	}
	if first.Totals.RowsRead != 2 || first.Totals.RowsWritten != 2 || first.Totals.RowsSkipped != 0 {
		t.Errorf("first run counts wrong: %+v", first.Totals)
	}
	if first.Totals.RowsDeduped != 0 {
		t.Errorf("first run should have 0 dedupes, got %d", first.Totals.RowsDeduped)
	}

	outPath := filepath.Join(root, "data/evidence/2026/05/02/distilled_facts.jsonl")
	rows := readJSONL(t, outPath)
	if len(rows) != 2 {
		t.Fatalf("expected 2 output rows, got %d", len(rows))
	}
	for _, r := range rows {
		if r["schema_version"].(float64) != 1 {
			t.Errorf("schema_version wrong: %v", r["schema_version"])
		}
		prov := r["provenance"].(map[string]any)
		if prov["source_file"] != "data/_kb/distilled_facts.jsonl" {
			t.Errorf("provenance.source_file: %v", prov["source_file"])
		}
		if prov["recorded_at"] != "2026-05-02T00:00:00Z" {
			t.Errorf("provenance.recorded_at: %v", prov["recorded_at"])
		}
	}

	// Second run with identical input + RecordedAt → all rows should
	// dedup, nothing newly written.
	second, err := MaterializeAll(MaterializeOptions{
		Root:       root,
		Transforms: transforms,
		RecordedAt: "2026-05-02T00:00:00Z",
	})
	if err != nil {
		t.Fatalf("second run: %v", err)
	}
	if second.Totals.RowsRead != 2 || second.Totals.RowsWritten != 0 || second.Totals.RowsDeduped != 2 {
		t.Errorf("idempotency broken; second run counts: %+v", second.Totals)
	}
	rows2 := readJSONL(t, outPath)
	if len(rows2) != 2 {
		t.Fatalf("output file grew on idempotent rerun: %d rows", len(rows2))
	}
}

func TestMaterializeAll_BadJSONLineGoesToSkips(t *testing.T) {
	root := t.TempDir()
	mustWriteFixture(t, root, "data/_kb/distilled_facts.jsonl",
		`{"run_id":"r1","source_label":"a","created_at":"2026-04-26T00:00:00Z","extractor":"q","text":"t"}
not-json
{"run_id":"r2","source_label":"b","created_at":"2026-04-26T01:00:00Z","extractor":"q","text":"t2"}`)

	transforms := []TransformDef{
		{SourceFileRelPath: "data/_kb/distilled_facts.jsonl", Transform: extractorTransform},
	}
	res, err := MaterializeAll(MaterializeOptions{
		Root:       root,
		Transforms: transforms,
		RecordedAt: "2026-05-02T00:00:00Z",
	})
	if err != nil {
		t.Fatalf("run: %v", err)
	}
	if res.Totals.RowsWritten != 2 {
		t.Errorf("good rows should still pass through; written=%d", res.Totals.RowsWritten)
	}
	if res.Totals.RowsSkipped != 1 {
		t.Errorf("bad-json row should be in skipped bucket; got %d", res.Totals.RowsSkipped)
	}
	if res.Receipt.ValidationPass {
		t.Errorf("validation_pass should be false when any row was skipped")
	}

	skipsPath := filepath.Join(root, "data/_kb/distillation_skips.jsonl")
	skips := readJSONL(t, skipsPath)
	if len(skips) != 1 {
		t.Fatalf("expected 1 skip record, got %d", len(skips))
	}
	if !strings.Contains(toJSON(t, skips[0]), "JSON.parse failed") {
		t.Errorf("skip record should mention parse failure: %v", skips[0])
	}
}

func TestMaterializeAll_DryRunWritesNothing(t *testing.T) {
	root := t.TempDir()
	mustWriteFixture(t, root, "data/_kb/distilled_facts.jsonl",
		`{"run_id":"r1","source_label":"a","created_at":"2026-04-26T00:00:00Z","extractor":"q","text":"t"}`)

	transforms := []TransformDef{
		{SourceFileRelPath: "data/_kb/distilled_facts.jsonl", Transform: extractorTransform},
	}
	res, err := MaterializeAll(MaterializeOptions{
		Root:       root,
		Transforms: transforms,
		RecordedAt: "2026-05-02T00:00:00Z",
		DryRun:     true,
	})
	if err != nil {
		t.Fatalf("dry run: %v", err)
	}
	if res.Totals.RowsRead != 1 || res.Totals.RowsWritten != 1 {
		t.Errorf("dry run should still count, got %+v", res.Totals)
	}
	outPath := filepath.Join(root, "data/evidence/2026/05/02/distilled_facts.jsonl")
	if _, err := os.Stat(outPath); !os.IsNotExist(err) {
		t.Errorf("dry run wrote output file (should not): err=%v", err)
	}
	if _, err := os.Stat(res.ReceiptPath); !os.IsNotExist(err) {
		t.Errorf("dry run wrote receipt (should not): err=%v", err)
	}
}

func TestMaterializeAll_MissingSourceTalliedAsWarning(t *testing.T) {
	root := t.TempDir()
	transforms := []TransformDef{
		{SourceFileRelPath: "data/_kb/distilled_facts.jsonl", Transform: extractorTransform},
	}
	res, err := MaterializeAll(MaterializeOptions{
		Root:       root,
		Transforms: transforms,
		RecordedAt: "2026-05-02T00:00:00Z",
	})
	if err != nil {
		t.Fatalf("run: %v", err)
	}
	if res.Sources[0].RowsPresent {
		t.Errorf("expected rows_present=false")
	}
	if !res.Receipt.ValidationPass {
		t.Errorf("missing source ≠ validation failure; got pass=%v warnings=%v", res.Receipt.ValidationPass, res.Receipt.Warnings)
	}
	if len(res.Receipt.Warnings) == 0 {
		t.Errorf("missing source should produce a warning")
	}
}

// ─── Helpers ─────────────────────────────────────────────────────

func mustWriteFixture(t *testing.T, root, relpath, content string) {
	t.Helper()
	full := filepath.Join(root, relpath)
	if err := os.MkdirAll(filepath.Dir(full), 0o755); err != nil {
		t.Fatalf("mkdir: %v", err)
	}
	if err := os.WriteFile(full, []byte(content), 0o644); err != nil {
		t.Fatalf("write fixture: %v", err)
	}
}

func readJSONL(t *testing.T, path string) []map[string]any {
	t.Helper()
	f, err := os.Open(path)
	if err != nil {
		t.Fatalf("open %s: %v", path, err)
	}
	defer f.Close()
	var out []map[string]any
	sc := bufio.NewScanner(f)
	sc.Buffer(make([]byte, 0, 1<<16), 1<<24)
	for sc.Scan() {
		line := sc.Bytes()
		if len(line) == 0 {
			continue
		}
		var row map[string]any
		if err := json.Unmarshal(line, &row); err != nil {
			t.Fatalf("parse %s: %v", path, err)
		}
		out = append(out, row)
	}
	if err := sc.Err(); err != nil {
		t.Fatalf("scan %s: %v", path, err)
	}
	return out
}

func toJSON(t *testing.T, v any) string {
	t.Helper()
	b, err := json.Marshal(v)
	if err != nil {
		t.Fatalf("marshal: %v", err)
	}
	return string(b)
}