package workphase

import (
	"strings"
	"testing"
)

func research() Research {
	return Research{
		Findings:   []Finding{{ID: "r1", Confidence: Fact, Claim: "attribution runs per figure", Evidence: "internal/attr/attr.go:88"}},
		Code:       []CodePath{{Path: "internal/attr/attr.go", Why: "aggregation happens here"}},
		Invariants: []string{"identity semantics must not change"},
		DeadEnds:   []DeadEnd{{Tried: "figure plurality", WhyFailed: "no measured gain"}},
	}
}

func plan() Plan {
	return Plan{
		Changes:      []Change{{Target: "internal/attr/attr.go", Intent: "aggregate per person"}},
		Verification: []string{"go test ./internal/attr/"},
	}
}

func TestRoundTrip(t *testing.T) {
	b, err := Encode(research())
	if err != nil {
		t.Fatal(err)
	}
	got, err := DecodeResearch(b)
	if err != nil {
		t.Fatal(err)
	}
	if got.Findings[0].Claim != "attribution runs per figure" || got.DeadEnds[0].Tried != "figure plurality" {
		t.Fatalf("round trip lost content: %+v", got)
	}
	pb, err := Encode(plan())
	if err != nil {
		t.Fatal(err)
	}
	gotPlan, err := DecodePlan(pb)
	if err != nil {
		t.Fatal(err)
	}
	if gotPlan.Changes[0].Target != "internal/attr/attr.go" {
		t.Fatalf("round trip lost content: %+v", gotPlan)
	}
}

// The bound is the point. An artifact that can hold a transcript is a
// transcript, and the next phase pays for reading it.
func TestBoundsRejectUnboundedArtifacts(t *testing.T) {
	cases := map[string]func() error{
		"no findings":     func() error { return Research{}.Validate() },
		"no evidence":     func() error { return Research{Findings: []Finding{{Claim: "x"}}}.Validate() },
		"multiline claim": func() error { return Research{Findings: []Finding{{Claim: "a\nb", Evidence: "e"}}}.Validate() },
		"long claim": func() error {
			return Research{Findings: []Finding{{Claim: strings.Repeat("x", 501), Evidence: "e"}}}.Validate()
		},
		"too many findings": func() error {
			r := Research{}
			for i := 0; i < 65; i++ {
				r.Findings = append(r.Findings, Finding{ID: "r1", Confidence: Fact, Claim: "c", Evidence: "e"})
			}
			return r.Validate()
		},
		"absolute path": func() error {
			r := research()
			r.Code = []CodePath{{Path: "/etc/passwd", Why: "no"}}
			return r.Validate()
		},
		"blank invariant": func() error {
			r := research()
			r.Invariants = []string{"  "}
			return r.Validate()
		},
		"no changes":       func() error { return Plan{}.Validate() },
		"no change intent": func() error { return Plan{Changes: []Change{{Target: "x"}}}.Validate() },
		"multiline risk": func() error {
			p := plan()
			p.Risks = []string{"a\nb"}
			return p.Validate()
		},
	}
	for name, fn := range cases {
		if err := fn(); err == nil {
			t.Fatalf("%s: expected rejection", name)
		}
	}
}

func TestEncodeRejectsInvalid(t *testing.T) {
	if _, err := Encode(Research{}); err == nil {
		t.Fatal("Encode must validate before sealing")
	}
	if _, err := DecodeResearch([]byte(`{"findings":[]}`)); err == nil {
		t.Fatal("Decode must validate")
	}
	if _, err := DecodePlan([]byte(`not json`)); err == nil {
		t.Fatal("Decode must reject non-JSON")
	}
}

// The advertised schema promised findings[].id and findings[].confidence while
// the struct carried neither, so both were dropped silently on every seal. A
// plan cannot cite what was never stored.
func TestFindingIdentityIsRequiredAndUnique(t *testing.T) {
	cases := map[string]Research{
		"no id":          {Findings: []Finding{{Confidence: Fact, Claim: "c", Evidence: "e"}}},
		"upper case id":  {Findings: []Finding{{ID: "R1", Confidence: Fact, Claim: "c", Evidence: "e"}}},
		"spaced id":      {Findings: []Finding{{ID: "r 1", Confidence: Fact, Claim: "c", Evidence: "e"}}},
		"no confidence":  {Findings: []Finding{{ID: "r1", Claim: "c", Evidence: "e"}}},
		"bad confidence": {Findings: []Finding{{ID: "r1", Confidence: "certain", Claim: "c", Evidence: "e"}}},
		"duplicate id": {Findings: []Finding{
			{ID: "r1", Confidence: Fact, Claim: "c", Evidence: "e"},
			{ID: "r1", Confidence: Inference, Claim: "d", Evidence: "f"},
		}},
	}
	for name, r := range cases {
		if err := r.Validate(); err == nil {
			t.Errorf("%s: accepted, want a refusal", name)
		}
	}
}

// Research sealed before ids existed must stay readable. Refusing it would
// block every task whose research predates the change, including at rotation,
// where the agent that could fix it is already gone.
func TestStoredResearchWithoutIdentityStillDecodes(t *testing.T) {
	legacy := []byte(`{"findings":[{"claim":"c","evidence":"e"},{"claim":"d","evidence":"f"}]}`)
	if _, err := DecodeResearch(legacy); err == nil {
		t.Fatal("a new seal without ids must be refused")
	}
	r, err := DecodeStoredResearch(legacy)
	if err != nil {
		t.Fatalf("stored decode: %v", err)
	}
	if r.Findings[0].ID != "legacy-1" || r.Findings[1].ID != "legacy-2" {
		t.Fatalf("backfilled ids are not stable: %+v", r.Findings)
	}
	// Inference, not fact: the old schema required evidence and made no
	// verification claim, so calling it fact would upgrade it on the way in.
	if r.Findings[0].Confidence != Inference {
		t.Fatalf("backfilled confidence is %q, want inference", r.Findings[0].Confidence)
	}
}