package creator

import (
	"context"
	"errors"
	"testing"
	"time"
)

func TestCreatorPureCoverageGuards(t *testing.T) {
	if got, err := selectCandidate(nil); err != nil || got != "" {
		t.Fatalf("empty candidate: %q %v", got, err)
	}
	if got, err := selectCandidate([]string{"one"}); err != nil || got != "one" {
		t.Fatalf("single candidate: %q %v", got, err)
	}
	got, err := selectCandidate([]string{"one", "two"})
	if err != nil || (got != "one" && got != "two") {
		t.Fatalf("multiple candidates: %q %v", got, err)
	}
	for _, input := range []StrategyInput{
		{},
		{Position: 1, Action: "invalid", EventTypes: []string{"comment"}},
		{Position: 1, Action: ActionLikeComment, TargetType: "work", EventTypes: []string{"comment"}},
		{Position: 1, Action: ActionLikeWork, TargetType: "comment", EventTypes: []string{"comment"}},
		{Position: 1, Action: ActionReplyComment, EventTypes: []string{"dm"}},
		{Position: 1, Action: ActionReplyComment, EventTypes: []string{"comment"}, CandidateTexts: []string{""}},
	} {
		if _, err := validateStrategyInput(input); !errors.Is(err, ErrInvalid) {
			t.Fatalf("invalid strategy input accepted: %+v -> %v", input, err)
		}
	}
	valid, err := validateStrategyInput(StrategyInput{Position: 1, Action: ActionReplyComment, EventTypes: []string{" comment "}, CandidateTexts: []string{" reply "}})
	if err != nil || valid.TargetType != "user" || valid.EventTypes[0] != "comment" || valid.CandidateTexts[0] != "reply" {
		t.Fatalf("valid strategy normalization: %+v %v", valid, err)
	}
	if result := actionPreconditionResult(ErrConflict, "blocked"); result.State != "blocked" || result.Reason != "blocked" {
		t.Fatalf("blocked precondition: %+v", result)
	}
	if result := actionPreconditionResult(errors.New("database down"), "ignored"); result.State != "uncertain" {
		t.Fatalf("uncertain precondition: %+v", result)
	}
	for _, result := range []ActionResult{{State: "succeeded"}, {State: "failed"}, {State: "blocked"}, {State: "uncertain"}, {}} {
		normalized := normalizeActionResult(result, nil)
		if normalized.State == "" {
			t.Fatalf("empty action result was not normalized: %+v", normalized)
		}
	}
	if result := normalizeActionResult(ActionResult{}, errors.New("executor failed")); result.State != "uncertain" || result.Reason != "executor failed" {
		t.Fatalf("executor error normalization: %+v", result)
	}
	if title, script, err := parseGeneratedRewrite(`{"title":" title ","script":" script "}`); err != nil || title != "title" || script != "script" {
		t.Fatalf("generated rewrite parse: %q %q %v", title, script, err)
	}
	for _, value := range []string{"not-json", `{"title":"","script":"script"}`, `{"title":"title","script":""}`} {
		if _, _, err := parseGeneratedRewrite(value); err == nil {
			t.Fatalf("invalid generated rewrite accepted: %s", value)
		}
	}
	if _, err := decodeCommentCheckpoint(`{"cursor":"missing-work-key"}`); !errors.Is(err, ErrInvalid) {
		t.Fatalf("invalid empty checkpoint: %v", err)
	}
	if value, err := decodeCommentCheckpoint(`{"work_key":"work","cursor":"cursor"}`); err != nil || value.WorkKey != "work" || value.Cursor != "cursor" {
		t.Fatalf("valid checkpoint: %+v %v", value, err)
	}
}

func TestCreatorSchedulingAndActionPredicates(t *testing.T) {
	now := time.Now().UTC()
	if next, reason := NextMetricAtValue(nil, now, SettingsUpdate{}); !next.IsZero() || reason != "published_at_pending_verification" {
		t.Fatalf("pending metric schedule: %v %q", next, reason)
	}
	published := now.Add(-time.Hour)
	input := SettingsUpdate{MetricInitialIntervalSeconds: 60, MetricMaxIntervalSeconds: 3600, MetricMultiplier: 2, MetricAgeSeconds: 7200}
	if next, reason := NextMetricAtValue(&published, now, input); next.IsZero() || reason != "" {
		t.Fatalf("metric schedule: %v %q", next, reason)
	}
	if coalesceReason("value", "fallback") != "value" || coalesceReason("", "fallback") != "fallback" {
		t.Fatal("coalesceReason did not choose the expected value")
	}
	for _, test := range []struct {
		action, interactor, comment, work string
		valid                             bool
	}{
		{ActionDM, "peer", "", "", true},
		{ActionFollow, "peer", "", "", true},
		{ActionReplyComment, "peer", "comment", "", true},
		{ActionLikeComment, "peer", "", "", false},
		{ActionLikeWork, "peer", "", "work", true},
		{ActionRepost, "peer", "", "", false},
		{ActionDM, "", "comment", "work", false},
		{"unknown", "peer", "comment", "work", false},
	} {
		if got := ActionTargetValid(test.action, test.interactor, test.comment, test.work, ""); got != test.valid {
			t.Fatalf("ActionTargetValid(%+v) = %v", test, got)
		}
	}
}

func TestCreatorPaginationGuards(t *testing.T) {
	items, err := collectPagesFromCursor(context.Background(), "", func(_ context.Context, cursor string) ([]string, string, bool, error) {
		if cursor != "" {
			t.Fatalf("unexpected cursor %q", cursor)
		}
		return []string{"one"}, "", false, nil
	}, nil)
	if err != nil || len(items) != 1 {
		t.Fatalf("single page: %v %v", items, err)
	}
	for name, fetch := range map[string]func(context.Context, string) ([]string, string, bool, error){
		"missing cursor":  func(context.Context, string) ([]string, string, bool, error) { return nil, "", true, nil },
		"repeated cursor": func(context.Context, string) ([]string, string, bool, error) { return nil, "same", true, nil },
	} {
		_, err := collectPagesFromCursor(context.Background(), "same", fetch, nil)
		if !errors.Is(err, ErrInvalid) {
			t.Fatalf("%s: %v", name, err)
		}
	}
	_, err = collectPagesFromCursor(context.Background(), "", func(context.Context, string) ([]string, string, bool, error) {
		return nil, "next", true, errors.New("fetch failed")
	}, nil)
	if err == nil || err.Error() != "fetch failed" {
		t.Fatalf("fetch failure: %v", err)
	}
	_, err = collectPagesFromCursor(context.Background(), "", func(context.Context, string) ([]string, string, bool, error) {
		return []string{"one"}, "next", true, nil
	}, func([]string, string, bool) error { return errors.New("save failed") })
	if err == nil || err.Error() != "save failed" {
		t.Fatalf("after-page failure: %v", err)
	}
}

func TestConfiguredBailianWithoutStore(t *testing.T) {
	var client *ConfiguredBailian
	if _, err := client.Generate(context.Background(), "instruction", "input"); !errors.Is(err, ErrUnavailable) {
		t.Fatalf("nil Generate: %v", err)
	}
	if _, _, err := client.MatchTheme(context.Background(), "title", "body", "topic"); !errors.Is(err, ErrUnavailable) {
		t.Fatalf("nil MatchTheme: %v", err)
	}
	if _, _, err := client.MatchLead(context.Background(), "work", "comment", "requirement"); !errors.Is(err, ErrUnavailable) {
		t.Fatalf("nil MatchLead: %v", err)
	}
}