package validators

import (
	"context"
	"strings"
	"testing"

	"gitea.maximumdirect.net/eric/audita/internal/core/config"
	"gitea.maximumdirect.net/eric/audita/internal/core/schema"
	"gitea.maximumdirect.net/eric/audita/internal/framework/proposals"
)

func mkCandidate(index int, segID int, orig, corr string, conf float64) proposals.EnrichedCorrectionProposal {
	return proposals.EnrichedCorrectionProposal{
		CorrectionProposal: proposals.CorrectionProposal{TargetSegmentID: segID, OriginalText: orig, CorrectedText: corr, Confidence: conf},
		ProposalMetadata:   proposals.ProposalMetadata{ProposalIndex: index, ModuleKey: "grammar", ModuleInstance: "grammar_1"},
	}
}

func TestEnforceDecisionCardinalitySuccess(t *testing.T) {
	candidates := []proposals.EnrichedCorrectionProposal{mkCandidate(0, 1, "teh", "the", 0.9), mkCandidate(1, 1, "recieve", "receive", 0.9)}
	decisions := []Decision{{ProposalIndex: 0, Approved: true}, {ProposalIndex: 1, Approved: false}}
	if err := EnforceDecisionCardinality(candidates, decisions); err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
}

func TestEnforceDecisionCardinalityMissingDecision(t *testing.T) {
	candidates := []proposals.EnrichedCorrectionProposal{mkCandidate(0, 1, "teh", "the", 0.9), mkCandidate(1, 1, "recieve", "receive", 0.9)}
	err := EnforceDecisionCardinality(candidates, []Decision{{ProposalIndex: 0, Approved: true}})
	if err == nil || !strings.Contains(err.Error(), "missing decision") {
		t.Fatalf("expected missing decision error, got %v", err)
	}
}

func TestEnforceDecisionCardinalityDuplicateDecision(t *testing.T) {
	candidates := []proposals.EnrichedCorrectionProposal{mkCandidate(0, 1, "teh", "the", 0.9)}
	err := EnforceDecisionCardinality(candidates, []Decision{{ProposalIndex: 0, Approved: true}, {ProposalIndex: 0, Approved: false}})
	if err == nil || !strings.Contains(err.Error(), "duplicate decision") {
		t.Fatalf("expected duplicate decision error, got %v", err)
	}
}

func TestEnforceDecisionCardinalityUnknownDecision(t *testing.T) {
	candidates := []proposals.EnrichedCorrectionProposal{mkCandidate(0, 1, "teh", "the", 0.9)}
	err := EnforceDecisionCardinality(candidates, []Decision{{ProposalIndex: 99, Approved: true}})
	if err == nil || !strings.Contains(err.Error(), "unknown decision") {
		t.Fatalf("expected unknown decision error, got %v", err)
	}
}

func TestConfidenceThresholdValidator(t *testing.T) {
	cfg := config.Default()
	cfg.Thresholds.Grammar = 0.8
	req := Request{ModuleKey: "grammar", Config: &cfg, CandidateProposal: []proposals.EnrichedCorrectionProposal{
		mkCandidate(0, 1, "teh", "the", 0.9),
		mkCandidate(1, 1, "recieve", "receive", 0.7),
	}}
	res, err := (ConfidenceThresholdValidator{}).Validate(context.Background(), req)
	if err != nil {
		t.Fatalf("Validate error: %v", err)
	}
	if !res.Decisions[0].Approved || res.Decisions[0].ReasonCode != ReasonApproved {
		t.Fatalf("expected first decision approved, got %+v", res.Decisions[0])
	}
	if res.Decisions[1].Approved || res.Decisions[1].ReasonCode != ReasonLowConfidence {
		t.Fatalf("expected second decision low confidence reject, got %+v", res.Decisions[1])
	}
}

func TestProposalShapeValidator(t *testing.T) {
	req := Request{CandidateProposal: []proposals.EnrichedCorrectionProposal{
		mkCandidate(0, 1, "teh", "the", 0.9),
		mkCandidate(1, 0, "teh", "the", 0.9),
		mkCandidate(2, 1, "   ", "the", 0.9),
		mkCandidate(3, 1, "teh", "the", 1.5),
	}}
	res, err := (ProposalShapeValidator{}).Validate(context.Background(), req)
	if err != nil {
		t.Fatalf("Validate error: %v", err)
	}
	if !res.Decisions[0].Approved {
		t.Fatalf("expected proposal 0 approved")
	}
	if res.Decisions[1].ReasonCode != ReasonInvalidTargetSegment {
		t.Fatalf("expected invalid target segment rejection, got %+v", res.Decisions[1])
	}
	if res.Decisions[2].ReasonCode != ReasonEmptyOriginalText {
		t.Fatalf("expected empty original rejection, got %+v", res.Decisions[2])
	}
	if res.Decisions[3].ReasonCode != ReasonInvalidConfidence {
		t.Fatalf("expected invalid confidence rejection, got %+v", res.Decisions[3])
	}
}

func TestOriginalTextPresenceValidator(t *testing.T) {
	req := Request{WorkingTranscript: &schema.Transcript{Segments: []schema.Segment{{ID: 1, Text: "hello world"}}}, CandidateProposal: []proposals.EnrichedCorrectionProposal{
		mkCandidate(0, 1, "hello", "hi", 0.9),
		mkCandidate(1, 1, "missing", "x", 0.9),
		mkCandidate(2, 5, "hello", "hi", 0.9),
	}}
	res, err := (OriginalTextPresenceValidator{}).Validate(context.Background(), req)
	if err != nil {
		t.Fatalf("Validate error: %v", err)
	}
	if !res.Decisions[0].Approved {
		t.Fatalf("expected proposal 0 approved")
	}
	if res.Decisions[1].ReasonCode != ReasonMissingOriginalText {
		t.Fatalf("expected missing_original_text, got %+v", res.Decisions[1])
	}
	if res.Decisions[2].ReasonCode != ReasonMissingTargetSegment {
		t.Fatalf("expected missing_target_segment, got %+v", res.Decisions[2])
	}
}

func TestNonEmptyCorrectionValidator(t *testing.T) {
	req := Request{
		WorkingTranscript: &schema.Transcript{Segments: []schema.Segment{{ID: 1, Text: "hello world"}}},
		ReplacementPolicy: proposals.ReplacementPolicyRequireUnique,
		CandidateProposal: []proposals.EnrichedCorrectionProposal{
			mkCandidate(0, 1, "hello", "hi", 0.9),
			mkCandidate(1, 1, "hello world", "   ", 0.9),
		}}
	res, err := (NonEmptyCorrectionValidator{}).Validate(context.Background(), req)
	if err != nil {
		t.Fatalf("Validate error: %v", err)
	}
	if !res.Decisions[0].Approved {
		t.Fatalf("expected proposal 0 approved")
	}
	if res.Decisions[1].ReasonCode != ReasonEmptyResultingText {
		t.Fatalf("expected empty_resulting_segment, got %+v", res.Decisions[1])
	}
}

func TestNoEffectValidator(t *testing.T) {
	req := Request{CandidateProposal: []proposals.EnrichedCorrectionProposal{
		mkCandidate(0, 1, "hello", "hello", 0.9),
		mkCandidate(1, 1, "hello", "hi", 0.9),
	}}
	res, err := (NoEffectValidator{}).Validate(context.Background(), req)
	if err != nil {
		t.Fatalf("Validate error: %v", err)
	}
	if res.Decisions[0].ReasonCode != ReasonNoEffect || res.Decisions[0].Approved {
		t.Fatalf("expected no_effect rejection, got %+v", res.Decisions[0])
	}
	if !res.Decisions[1].Approved {
		t.Fatalf("expected proposal 1 approved")
	}
}

func TestValidateProtectedTerms(t *testing.T) {
	glossary := &schema.Glossary{Entries: []schema.GlossaryEntry{{Name: "OpenAI", Aliases: []string{"Open AI"}, Plural: "OpenAIs", Category: "brand", Summary: "brand"}}}
	req := Request{
		Glossary:  glossary,
		ModuleKey: "grammar",
		CandidateProposal: []proposals.EnrichedCorrectionProposal{
			mkCandidate(0, 1, "OpenAI", "Open A I", 0.9),
			mkCandidate(1, 1, "teh", "the", 0.9),
		},
	}
	res, err := ValidateProtectedTerms(req, false)
	if err != nil {
		t.Fatalf("Validate error: %v", err)
	}
	if res.Decisions[0].ReasonCode != ReasonProtectedGlossaryTerm || res.Decisions[0].Approved {
		t.Fatalf("expected protected glossary rejection, got %+v", res.Decisions[0])
	}
	if !res.Decisions[1].Approved {
		t.Fatalf("expected non-glossary proposal approved")
	}
}

func TestStableReasonCodes(t *testing.T) {
	codes := []string{
		ReasonApproved,
		ReasonLowConfidence,
		ReasonMissingOriginalText,
		ReasonMissingTargetSegment,
		ReasonEmptyResultingText,
		ReasonNoEffect,
		ReasonProtectedGlossaryTerm,
		ReasonInvalidTargetSegment,
		ReasonEmptyOriginalText,
		ReasonInvalidConfidence,
		ReasonValidatorMalformed,
		ReasonValidatorInputTooLarge,
	}
	for _, code := range codes {
		if strings.TrimSpace(code) == "" {
			t.Fatalf("reason code must not be empty")
		}
	}
}