package pipeline

// oracle_test.go: the cold-run-A oracle, IN THE TREE.
//
// ⛔ WHY IT IS HERE AND NOT IN A REPORT. The pack's own rule is that what must survive a restart lives in
// the repository; the comparison against the polygon's hand-built table (docs/experiments/24-door-to-file.md
// §7) existed only in a written report, so the single number the whole instrument was accepted on — «it
// reproduces the oracle» — could not be re-checked by anyone, ever. The TABLE is committed
// (testdata/oracle-run-a.json); the paid artifacts it is measured against are not, so the test skips when
// they are absent, exactly as the labelled-corpus harness next door does.
//
// ⚠ IT SKIPS UNDER A COPY-BASED WORKFLOW (tmmutate), because standdata.Root walks to the repo root and the
// books tree is not copied with the module. Named rather than implied: this pin is held by the battery and
// not by the mutation gate.

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

	"textmachine/backend/internal/lang"
	"textmachine/backend/internal/membank"
	"textmachine/backend/internal/standdata"
	"textmachine/backend/internal/store"
)

var runADir = standdata.EnvOr("TM_RUN_A_DIR", standdata.StandFile("gu-zhenren", "door-to-file"))

type oracleTerm struct {
	Src        string `json:"src"`
	BankDst    string `json:"bank_dst"`
	Population string `json:"population"`
	Oracle     string `json:"oracle"`
	Instrument string `json:"instrument"`
	Agrees     bool   `json:"agrees"`
}

type oracleDoc struct {
	Agree int          `json:"agree"`
	Terms []oracleTerm `json:"terms"`
}

// frozenBank builds the bank as it stood at the mining stop of 04:39, from the projection that IS the
// frozen evidence. The stand database is a DIFFERENT revision — 12 rows were re-consolidated at 04:42 —
// so judging the oracle against it would be judging a different bank.
func frozenBank(t *testing.T) *membank.Bank {
	t.Helper()
	raw, err := os.ReadFile(filepath.Join(runADir, "bankstop-paid", "project.db.bank.json"))
	if err != nil {
		t.Skipf("run-A evidence absent (%v) — set TM_RUN_A_DIR to force", err)
	}
	var doc struct {
		Proposed []struct{ Src, Dst string } `json:"proposed"`
	}
	if err := json.Unmarshal(raw, &doc); err != nil {
		t.Fatalf("parse the frozen bank projection: %v", err)
	}
	rows := make([]store.GlossaryEntry, 0, len(doc.Proposed))
	for _, p := range doc.Proposed {
		rows = append(rows, store.GlossaryEntry{BookID: "runA", Src: p.Src, Dst: p.Dst, Status: "draft", Source: "seed"})
	}
	if len(rows) == 0 {
		t.Fatalf("the frozen bank projection carries no proposals")
	}
	return membank.MaterializeBank(membank.BankInput{
		Rows: rows, TargetStemmer: lang.NewTargetStemmer(lang.TargetChecksFor("ru")),
	}, false)
}

// TestTheInstrumentAgainstTheColdRunOracle re-runs the comparison the pack was accepted on, over the same
// shipped units, and pins BOTH halves: which terms agree and which do not. A disagreement is not a failure
// here — three of them are properties this engine documents — but a disagreement that CHANGES is, because
// it means the instrument's verdict moved without anyone deciding that it should.
func TestTheInstrumentAgainstTheColdRunOracle(t *testing.T) {
	raw, err := os.ReadFile(filepath.Join("testdata", "oracle-run-a.json"))
	if err != nil {
		t.Fatalf("the oracle table is part of the repository: %v", err)
	}
	var want oracleDoc
	if err := json.Unmarshal(raw, &want); err != nil {
		t.Fatalf("parse the oracle table: %v", err)
	}
	bank := frozenBank(t) // skips when the paid artifacts are absent

	pairs, err := os.ReadFile(filepath.Join(runADir, "pairs.json"))
	if err != nil {
		t.Skipf("run-A shipped units absent (%v) — set TM_RUN_A_DIR to force", err)
	}
	var exp struct {
		Chunks []struct {
			Chapter   int    `json:"chapter"`
			Source    string `json:"source"`
			FinalText string `json:"final_text"`
		} `json:"chunks"`
	}
	if err := json.Unmarshal(pairs, &exp); err != nil {
		t.Fatalf("parse the shipped units: %v", err)
	}
	c := newConsistencyScan(bank)
	for _, u := range exp.Chunks {
		c.add(u.Chapter, u.Source, u.FinalText)
	}
	// The denominator is the bank the scan actually ran over, so the partition below is about the same rows.
	rows := make([]store.GlossaryEntry, 0)
	for _, term := range want.Terms {
		rows = append(rows, store.GlossaryEntry{BookID: "runA", Src: term.Src, Dst: term.BankDst, Status: "draft"})
	}
	got := c.finish(rows)

	verdict := map[string]string{}
	for _, term := range got.Terms {
		verdict[term.Src] = term.Verdict
	}
	agree := 0
	for _, term := range want.Terms {
		v := verdict[term.Src]
		if v == "" {
			v = "covered"
		}
		if v != term.Instrument {
			t.Errorf("%s: the instrument now says %q where the table records %q (the oracle says %q) — a verdict moved without anyone deciding it should",
				term.Src, v, term.Instrument, term.Oracle)
		}
		if v == term.Oracle {
			agree++
		}
	}
	if agree != want.Agree {
		t.Errorf("agreement with the hand-built oracle is %d of %d; the table records %d", agree, len(want.Terms), want.Agree)
	}
	t.Logf("oracle agreement: %d of %d terms (the table's recorded disagreements are documented properties, not defects)", agree, len(want.Terms))
}