package processing

import (
	"context"
	"encoding/json"
	"strings"
	"testing"

	"github.com/descrybe/descrybe-v2/apps/api/internal/aiprompts"
	"github.com/descrybe/descrybe-v2/apps/api/internal/company"
)

// A categorised product with no formula of its own enhances through the English
// platform default rather than the generic "1-3 paragraphs" rule.
func TestWithDefaultCategoryFormula_appliesToCategorisedProduct(t *testing.T) {
	t.Parallel()
	got := withDefaultCategoryFormula(ProductInput{
		CategoryUniqueID:    "high-chairs",
		CategoryDisplayName: "High chairs",
	})
	if got.CategoryEnhancePrompt == "" {
		t.Fatal("expected the platform default overlay")
	}
	if FormatTitleFormulaConstraint(got.TitleTemplate) == "" {
		t.Fatalf("expected a default title formula, got %#v", got.TitleTemplate)
	}
	if FormatDescriptionFormulaConstraint(got.DescriptionTemplate) == "" {
		t.Fatalf("expected a default description formula, got %#v", got.DescriptionTemplate)
	}
}

func TestWithDefaultCategoryFormula_doesNotOverride(t *testing.T) {
	t.Parallel()
	cases := map[string]ProductInput{
		"no category at all": {},
		"category prompt already set": {
			CategoryUniqueID:      "high-chairs",
			CategoryEnhancePrompt: "--- Title ---\nKeep the supplier title.\n--- End Title ---",
		},
		"tenant-authored enhance template": {
			CategoryUniqueID:    "high-chairs",
			EnhanceUserTemplate: "Write a haiku about {{name}}",
		},
		"category has its own title formula": {
			CategoryUniqueID: "high-chairs",
			TitleTemplate: map[string]any{"separator": " ", "elements": []any{
				map[string]any{"type": "variable", "value": "product_type"},
				map[string]any{"type": "variable", "value": "brand"},
			}},
		},
	}
	for name, in := range cases {
		t.Run(name, func(t *testing.T) {
			got := withDefaultCategoryFormula(in)
			if got.CategoryEnhancePrompt != in.CategoryEnhancePrompt {
				t.Fatalf("platform default overrode an explicit choice: %q", got.CategoryEnhancePrompt)
			}
		})
	}
}

// A1's Slovenian formulas keep the Slovenian scaffolding and system prompt they had
// in generator.php; the English defaults get an English frame. Output language is
// set by {{language}} in both cases.
func TestResolveProductPromptTemplates_scaffoldingFollowsFormulaLanguage(t *testing.T) {
	t.Parallel()
	slovenian := aiprompts.SplitLegacyCombinedEnhancePrompt(a1StolckiLegacyPrompt)
	sysSL, userSL := resolveProductPromptTemplates(ProductInput{
		CategoryUniqueID:      "stolcki",
		CategoryDisplayName:   "Stolčki",
		CategoryEnhancePrompt: slovenian,
		Language:              "sl",
	})
	if !strings.Contains(sysSL, "Si tekstopisec") {
		t.Fatalf("Slovenian formula must keep the Slovenian system prompt:\n%s", sysSL)
	}
	for _, want := range []string{"GPT predloga:", "Staro_ime_izdelka: {{name}}", "<name>{"} {
		if !strings.Contains(userSL, want) {
			t.Fatalf("Slovenian scaffolding missing %q:\n%s", want, userSL)
		}
	}

	sysEN, userEN := resolveProductPromptTemplates(ProductInput{
		CategoryUniqueID:    "high-chairs",
		CategoryDisplayName: "High chairs",
	})
	if !strings.Contains(sysEN, "You are a copywriter") {
		t.Fatalf("English default must use the English system prompt:\n%s", sysEN)
	}
	for _, want := range []string{"Product template:", "Old_product_name: {{name}}", "<name>{"} {
		if !strings.Contains(userEN, want) {
			t.Fatalf("English scaffolding missing %q:\n%s", want, userEN)
		}
	}
	if strings.Contains(userEN, "GPT predloga") || strings.Contains(userEN, "Staro_ime_izdelka") {
		t.Fatalf("English default leaked Slovenian scaffolding:\n%s", userEN)
	}
}

// End to end through RunSteps: a category with no stored formula still produces
// formula-shaped HTML and a rebuilt name, and the feed is only used as evidence.
func TestRunSteps_defaultFormulaDrivesGeneration(t *testing.T) {
	t.Parallel()
	reply, _ := json.Marshal(map[string]any{
		"name": "BRUNNER folding chair ONE SHOT 0404164N.C20",
		"description": "<h2>BRUNNER folding chair for life on the road</h2><p>" +
			strings.Repeat("A light aluminium frame opens in one motion and stays steady on uneven ground. ", 4) +
			"</p><h2>Built to last a season outdoors</h2><p>" +
			strings.Repeat("Reinforced joints take the load where it matters and wipe clean in seconds. ", 4) +
			"</p><b>Technical specifications</b><ul><li>Brand: BRUNNER</li><li>Material: aluminium</li></ul>",
		"attrs": map[string]any{"brand": "BRUNNER", "product_model": "ONE SHOT 0404164N.C20"},
	})
	c := &formulaRegressionCompleter{reply: string(reply)}
	feedName := "BRUNNER folding camping chair ONE SHOT grey black 0404164N.C20"
	feedDesc := "An elegant and very light chair designed for art directors. Folding aluminium frame and armrests."

	out, err := (&Engine{Completer: c}).RunSteps(context.Background(), "co", ProductInput{
		GTIN:        "8022068075495",
		Name:        feedName,
		Description: feedDesc,
		Mapped: map[string]any{
			"name": feedName, "description": feedDesc,
			"brand": "BRUNNER", "category": "high-chairs",
			"specifications": map[string]any{"Material": "aluminium"},
		},
		Language:           "en",
		ContentLanguages:   []string{"en"},
		CategoryNamesByUID: map[string]string{"high-chairs": "High chairs"},
	}, "full", []string{"high-chairs"}, StepPolicy{AllowAI: true})
	if err != nil {
		t.Fatal(err)
	}
	if c.calls != 1 {
		t.Fatalf("a compliant reply must not need a retry, calls=%d", c.calls)
	}
	if !strings.Contains(c.user, "Product template:") || !strings.Contains(c.user, "<H2>{") {
		t.Fatalf("default formula never reached the prompt:\n%s", c.user)
	}
	if out.ProcessedName == out.Name || out.ProcessedDescription == out.Description {
		t.Fatal("enriched output must differ from the feed")
	}
	if !strings.Contains(out.ProcessedDescription, "<h2>") || !strings.Contains(out.ProcessedDescription, "<ul>") {
		t.Fatalf("processed description is not formula HTML: %q", out.ProcessedDescription)
	}
	if out.Name != feedName || out.Description != feedDesc {
		t.Fatalf("Original must stay the feed: name=%q desc=%q", out.Name, out.Description)
	}
	if h, _ := out.FieldSources[FieldEnhanceInputHash].(string); h == "" {
		t.Fatal("quality enhance under the default formula must persist a hash")
	}
	_ = company.DefaultLanguage
}