//go:build integration

package integration

import (
	"context"
	"testing"

	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"

	"github.com/missionworkforce/missionmatch/internal/modules/matching"
	"github.com/missionworkforce/missionmatch/internal/platform/database/dbgen"
)

// TestSharedCoreScoresIdenticalAcrossTools proves the central acceptance criterion of the three tool
// separation: the SAME candidate against the SAME requirement produces byte identical numbers no
// matter which tool path computed it. screenMATCH (ScreenCandidate and the Screen Mission Readiness
// view) and slateMATCH (GenerateSlate, which persists the frozen member score) both run the one shared
// engine, so the total and band must agree to the cent. This is the regression lock for Workstreams B,
// C, and D: when the flat handler is split across three routers, this test stays green or a number
// drifted.
//
// The candidate is deliberately partial (75.00, the Yellow boundary): Secret active meets the Secret
// requirement (100), no skills or certs are required (100), but there is no DISA customer history (0),
// only 5 of 10 required years (50), and a fixed work location the candidate neither matches nor will
// relocate to while still being available (50). 25 + 25 + 15 + 0 + 5 + 5 = 75.00.
func TestSharedCoreScoresIdenticalAcrossTools(t *testing.T) {
	ctx := context.Background()
	org := seedOrg(t)

	agency := "DISA"
	location := "Fort Meade, MD"
	req, err := dbgen.New(migrator).CreateRequirement(ctx, dbgen.CreateRequirementParams{
		OrganizationID: org, Title: "Cross Tool Role", RequiredLevel: "secret", RequiredPoly: "none",
		RequiredYears: 10, CustomerAgency: &agency, WorkLocation: &location, RemoteAllowed: false,
	})
	if err != nil {
		t.Fatalf("seed requirement: %v", err)
	}

	cand := seedCandidate(t, org, "secret", "active", true)
	if _, err := migrator.Exec(ctx,
		"UPDATE candidates SET years_experience=5 WHERE id=$1", cand.ID); err != nil {
		t.Fatalf("enrich candidate: %v", err)
	}

	svc := matching.NewService(appDB, nil, nil) // exact only matcher; the engine is the shared core

	// screenMATCH path 1: the raw explainable result.
	mr, err := svc.ScreenCandidate(ctxOrg(org), cand.ID, req.ID)
	if err != nil {
		t.Fatalf("ScreenCandidate: %v", err)
	}
	screenTotal := mr.Total.StringFixed(2)

	// screenMATCH path 2: the Mission Readiness view a recruiter sees.
	view, err := svc.Screen(ctxOrg(org), cand.ID, req.ID)
	if err != nil {
		t.Fatalf("Screen: %v", err)
	}

	// slateMATCH path: generate the slate, which scores and FREEZES the member at generation time.
	slate, err := svc.GenerateSlate(ctxOrg(org), matching.GenerateSlateInput{RequirementID: req.ID, Name: "Cross Tool Slate"})
	if err != nil {
		t.Fatalf("GenerateSlate: %v", err)
	}
	if len(slate.Members) != 1 || slate.Members[0].CandidateID != cand.ID.String() {
		t.Fatalf("expected one slate member for the candidate, got %+v", slate.Members)
	}
	slateTotal := slate.Members[0].Total

	// The persisted decision record (what missionMATCH rollups read, never recompute).
	var members []dbgen.SlateMember
	if err := readMembers(ctxOrg(org), slate.SlateID, &members); err != nil {
		t.Fatalf("read back slate members: %v", err)
	}
	if len(members) != 1 {
		t.Fatalf("expected one persisted member, got %d", len(members))
	}
	persistedTotal := members[0].TotalScore.StringFixed(2)

	// Every path must agree to the cent.
	const want = "75.00"
	for label, got := range map[string]string{
		"screenMATCH ScreenCandidate":     screenTotal,
		"screenMATCH Screen view":         view.MissionReadiness.Score,
		"slateMATCH generated member":     slateTotal,
		"slateMATCH persisted member row": persistedTotal,
	} {
		if got != want {
			t.Fatalf("%s scored %s, every tool must score %s for the same candidate", label, got, want)
		}
	}

	// The band must agree too: 75.00 is the Yellow lower bound.
	if mr.Band.String() != "Yellow" || slate.Members[0].Band != "yellow" {
		t.Fatalf("band disagreement: screen=%s slate=%s, want Yellow", mr.Band, slate.Members[0].Band)
	}
}

// readMembers reads the persisted slate member rows under the org tenant transaction.
func readMembers(ctx context.Context, slateID uuid.UUID, out *[]dbgen.SlateMember) error {
	return appDB.RunInTenantTx(ctx, func(ctx context.Context, tx pgx.Tx) error {
		rows, e := dbgen.New(tx).ListSlateMembers(ctx, slateID)
		if e != nil {
			return e
		}
		*out = rows
		return nil
	})
}