package runtimeconfig

import (
	"os"
	"path/filepath"
	"strings"
	"testing"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/config"
)

func envCfg() config.LLMConfig {
	return config.LLMConfig{
		Provider: ProviderOpenAI,
		BaseURL:  "https://api.openai.com/v1",
		APIKey:   "sk-env",
		Model:    "gpt-4o",
		Fallback: "gpt-4o-mini",
	}
}

func writeModelsFile(t *testing.T, content string) string {
	t.Helper()
	path := filepath.Join(t.TempDir(), "models.json")
	if err := os.WriteFile(path, []byte(content), 0o600); err != nil {
		t.Fatalf("write models.json: %v", err)
	}
	return path
}

func TestLoadModels_FileValid(t *testing.T) {
	path := writeModelsFile(t, `[
		{"id":"openai","provider":"openai","baseUrl":"https://api.openai.com/v1","apiKey":"sk-1","model":"gpt-4o","fallback":"gpt-4o-mini","multimodal":true}
	]`)
	groups, warn := LoadModels(path, envCfg())
	if warn != nil {
		t.Fatalf("warn = %v, want nil", warn)
	}
	if len(groups) != 1 {
		t.Fatalf("len(groups) = %d, want 1", len(groups))
	}
	g := groups[0]
	if g.ID != "openai" || g.Provider != ProviderOpenAI || g.Model != "gpt-4o" || !g.Multimodal {
		t.Fatalf("group = %+v, want openai/gpt-4o/multimodal", g)
	}
}

func TestLoadModels_MissingFileFallsBackEnv(t *testing.T) {
	path := filepath.Join(t.TempDir(), "nonexistent.json")
	groups, warn := LoadModels(path, envCfg())
	if warn != nil {
		t.Fatalf("warn = %v, want nil (missing file is the normal case)", warn)
	}
	if len(groups) != 1 || groups[0].Model != "gpt-4o" || groups[0].APIKey != "sk-env" {
		t.Fatalf("groups = %+v, want env fallback gpt-4o/sk-env", groups)
	}
}

func TestLoadModels_InvalidFallsBackEnvWithWarn(t *testing.T) {
	path := writeModelsFile(t, `{ not json`)
	groups, warn := LoadModels(path, envCfg())
	if warn == nil {
		t.Fatal("warn = nil, want a warning for an invalid file")
	}
	if len(groups) != 1 || groups[0].APIKey != "sk-env" {
		t.Fatalf("groups = %+v, want env fallback", groups)
	}
}

func TestLoadModels_EmptyArrayFallsBackEnv(t *testing.T) {
	path := writeModelsFile(t, `[]`)
	groups, warn := LoadModels(path, envCfg())
	if warn == nil {
		t.Fatal("warn = nil, want a warning for an empty file")
	}
	if len(groups) != 1 {
		t.Fatalf("groups = %+v, want env fallback single group", groups)
	}
}

func TestValidate(t *testing.T) {
	valid := Group{ID: "a", Provider: ProviderOpenAI, BaseURL: "https://x", Model: "m"}
	if err := valid.Validate(); err != nil {
		t.Fatalf("valid group: %v", err)
	}
	cases := []Group{
		{ID: "", Provider: ProviderOpenAI, BaseURL: "https://x", Model: "m"},
		{ID: "a", Provider: "bogus", BaseURL: "https://x", Model: "m"},
		{ID: "a", Provider: ProviderOpenAI, BaseURL: "", Model: "m"},
		{ID: "a", Provider: ProviderOpenAI, BaseURL: "https://x", Model: ""},
	}
	for i, c := range cases {
		if err := c.Validate(); err == nil {
			t.Fatalf("case %d failed to validate: %+v", i, c)
		}
	}
}

func TestToLLMConfig(t *testing.T) {
	g := Group{ID: "a", Provider: ProviderOpenAI, BaseURL: "https://x", APIKey: "sk", Model: "m", Fallback: "f"}
	cfg := g.ToLLMConfig()
	if cfg.Provider != ProviderOpenAI || cfg.BaseURL != "https://x" || cfg.APIKey != "sk" || cfg.Model != "m" || cfg.Fallback != "f" {
		t.Fatalf("ToLLMConfig = %+v", cfg)
	}
	ag := Group{ID: "b", Provider: ProviderAnthropic, BaseURL: "https://y", APIKey: "sk2", Model: "claude"}
	acfg := ag.ToLLMConfig()
	if acfg.Provider != ProviderAnthropic || acfg.AnthropicBaseURL != "https://y" || acfg.AnthropicModel != "claude" {
		t.Fatalf("anthropic ToLLMConfig = %+v", acfg)
	}
}

func TestMaskedKey(t *testing.T) {
	empty := Group{APIKey: ""}.MaskedKey()
	if empty != "" {
		t.Fatalf("empty key masked = %q, want empty", empty)
	}
	short := Group{APIKey: "abc"}.MaskedKey()
	if short != "****" {
		t.Fatalf("short key masked = %q, want ****", short)
	}
	long := Group{APIKey: "sk-abcdef1234"}.MaskedKey()
	if long != "****1234" || strings.Contains(long, "sk-") {
		t.Fatalf("masked = %q, want ****1234 without the prefix", long)
	}
}

func TestActivate(t *testing.T) {
	base := []Group{
		{ID: "openai", Provider: ProviderOpenAI, BaseURL: "https://a", Model: "gpt-4o"},
		{ID: "anthropic", Provider: ProviderAnthropic, BaseURL: "https://b", Model: "claude"},
	}
	// New group is prepended (becomes the active index 0).
	out := Activate(base, Group{ID: "deepseek", Provider: ProviderOpenAI, BaseURL: "https://c", Model: "ds"})
	if len(out) != 3 || out[0].ID != "deepseek" || out[1].ID != "openai" || out[2].ID != "anthropic" {
		t.Fatalf("Activate new = %+v", out)
	}
	// An existing group is replaced and promoted to the front.
	out2 := Activate(out, Group{ID: "openai", Provider: ProviderOpenAI, BaseURL: "https://a2", Model: "gpt-4o-new"})
	if len(out2) != 3 || out2[0].ID != "openai" || out2[0].Model != "gpt-4o-new" || out2[1].ID != "deepseek" {
		t.Fatalf("Activate existing = %+v", out2)
	}
}

func TestSaveLoadRoundTrip(t *testing.T) {
	path := filepath.Join(t.TempDir(), "models.json")
	in := []Group{
		{ID: "openai", Provider: ProviderOpenAI, BaseURL: "https://a", APIKey: "sk-secret", Model: "gpt-4o", Multimodal: true},
		{ID: "anthropic", Provider: ProviderAnthropic, BaseURL: "https://b", APIKey: "sk-ant", Model: "claude"},
	}
	if err := SaveModels(path, in); err != nil {
		t.Fatalf("SaveModels: %v", err)
	}
	groups, warn := LoadModels(path, envCfg())
	if warn != nil {
		t.Fatalf("warn = %v", warn)
	}
	if len(groups) != 2 || groups[0].APIKey != "sk-secret" || groups[1].APIKey != "sk-ant" {
		t.Fatalf("round trip = %+v", groups)
	}
	// The key stays in the file (it is the runtime config), but never leaks into
	// the masked view.
	if got := groups[0].MaskedKey(); got != "****cret" {
		t.Fatalf("masked key = %q, want ****cret", got)
	}
}

func TestGroupMaxTokensRoundTrip(t *testing.T) {
	// maxTokens is decoded from a hand-written models.json.
	path := writeModelsFile(t, `[
		{"id":"openai","provider":"openai","baseUrl":"https://a","apiKey":"sk-1","model":"gpt-4o","maxTokens":4096}
	]`)
	groups, warn := LoadModels(path, envCfg())
	if warn != nil {
		t.Fatalf("warn = %v, want nil", warn)
	}
	if len(groups) != 1 || groups[0].MaxTokens != 4096 {
		t.Fatalf("groups = %+v, want one group with maxTokens 4096", groups)
	}

	// SaveModels writes it back, and LoadModels reads it again.
	out := filepath.Join(t.TempDir(), "models.json")
	in := []Group{
		{ID: "openai", Provider: ProviderOpenAI, BaseURL: "https://a", APIKey: "sk-1", Model: "gpt-4o", MaxTokens: 2048},
		{ID: "claude", Provider: ProviderAnthropic, BaseURL: "https://b", APIKey: "sk-2", Model: "claude"},
	}
	if err := SaveModels(out, in); err != nil {
		t.Fatalf("SaveModels: %v", err)
	}
	raw, err := os.ReadFile(out)
	if err != nil {
		t.Fatalf("read saved file: %v", err)
	}
	if !strings.Contains(string(raw), `"maxTokens": 2048`) {
		t.Errorf("saved file missing maxTokens: %s", raw)
	}
	round, warn := LoadModels(out, envCfg())
	if warn != nil {
		t.Fatalf("load warn = %v", warn)
	}
	if round[0].MaxTokens != 2048 || round[1].MaxTokens != 0 {
		t.Fatalf("round trip maxTokens = (%d,%d), want (2048,0)", round[0].MaxTokens, round[1].MaxTokens)
	}

	// Upsert and Activate preserve the field.
	upserted := Upsert(round, Group{ID: "openai", Provider: ProviderOpenAI, BaseURL: "https://a2", Model: "gpt-4o", MaxTokens: 3000})
	if upserted[0].MaxTokens != 3000 {
		t.Errorf("Upsert maxTokens = %d, want 3000", upserted[0].MaxTokens)
	}
	activated := Activate(round, Group{ID: "claude", Provider: ProviderAnthropic, BaseURL: "https://b", Model: "claude", MaxTokens: 512})
	if activated[0].MaxTokens != 512 {
		t.Errorf("Activate maxTokens = %d, want 512", activated[0].MaxTokens)
	}

	// A negative budget is rejected by validation (never silently persisted).
	if err := (Group{ID: "x", Provider: ProviderOpenAI, BaseURL: "https://x", Model: "m", MaxTokens: -1}).Validate(); err == nil {
		t.Fatal("expected Validate to reject a negative maxTokens")
	}
}

func TestSaveModels_RejectsInvalid(t *testing.T) {
	path := filepath.Join(t.TempDir(), "models.json")
	if err := SaveModels(path, []Group{{ID: "", Provider: "x", BaseURL: "https://a", Model: "m"}}); err == nil {
		t.Fatal("expected error saving an invalid group")
	}
	if _, statErr := os.Stat(path); !os.IsNotExist(statErr) {
		t.Fatalf("file should not be written when validation fails")
	}
}