package handler

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"gcy_hpc_server/internal/model"
	"gcy_hpc_server/internal/server"
	"gcy_hpc_server/internal/store"

	"github.com/gin-gonic/gin"
	"go.uber.org/zap"
	"go.uber.org/zap/zapcore"
	"go.uber.org/zap/zaptest/observer"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"
)

func setupTemplateHandler() (*TemplateHandler, *gorm.DB) {
	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{Logger: logger.Default.LogMode(logger.Silent)})
	db.AutoMigrate(&model.JobTemplate{})
	s := store.NewTemplateStore(db)
	h := NewTemplateHandler(s, zap.NewNop())
	return h, db
}

func setupTemplateRouter(h *TemplateHandler) *gin.Engine {
	gin.SetMode(gin.TestMode)
	r := gin.New()
	v1 := r.Group("/api/v1")
	templates := v1.Group("/templates")
	templates.GET("", h.ListTemplates)
	templates.POST("", h.CreateTemplate)
	templates.GET("/:id", h.GetTemplate)
	templates.PUT("/:id", h.UpdateTemplate)
	templates.DELETE("/:id", h.DeleteTemplate)
	return r
}

func TestListTemplates_Success(t *testing.T) {
	h, _ := setupTemplateHandler()
	r := setupTemplateRouter(h)

	// Seed data
	h.store.Create(context.Background(), &model.CreateTemplateRequest{Name: "test-tpl", Script: "echo hi", Partition: "normal", QOS: "high", CPUs: 4, Memory: "4GB"})

	w := httptest.NewRecorder()
	req, _ := http.NewRequest("GET", "/api/v1/templates", nil)
	r.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}
	var resp server.APIResponse
	json.Unmarshal(w.Body.Bytes(), &resp)
	if !resp.Success {
		t.Fatalf("expected success=true, got: %s", w.Body.String())
	}
}

func TestCreateTemplate_Success(t *testing.T) {
	h, _ := setupTemplateHandler()
	r := setupTemplateRouter(h)

	body := `{"name":"my-tpl","description":"desc","script":"echo hello","partition":"gpu"}`
	w := httptest.NewRecorder()
	req, _ := http.NewRequest("POST", "/api/v1/templates", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	r.ServeHTTP(w, req)

	if w.Code != http.StatusCreated {
		t.Fatalf("expected 201, got %d: %s", w.Code, w.Body.String())
	}
	var resp server.APIResponse
	json.Unmarshal(w.Body.Bytes(), &resp)
	if !resp.Success {
		t.Fatalf("expected success=true, got: %s", w.Body.String())
	}
}

func TestCreateTemplate_MissingFields(t *testing.T) {
	h, _ := setupTemplateHandler()
	r := setupTemplateRouter(h)

	body := `{"name":"","script":""}`
	w := httptest.NewRecorder()
	req, _ := http.NewRequest("POST", "/api/v1/templates", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	r.ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Fatalf("expected 400, got %d: %s", w.Code, w.Body.String())
	}
}

func TestGetTemplate_Success(t *testing.T) {
	h, _ := setupTemplateHandler()
	r := setupTemplateRouter(h)

	// Seed data
	id, _ := h.store.Create(context.Background(), &model.CreateTemplateRequest{Name: "test-tpl", Script: "echo hi", Partition: "normal"})

	w := httptest.NewRecorder()
	req, _ := http.NewRequest("GET", "/api/v1/templates/"+itoa(id), nil)
	r.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}
	var resp server.APIResponse
	json.Unmarshal(w.Body.Bytes(), &resp)
	if !resp.Success {
		t.Fatalf("expected success=true, got: %s", w.Body.String())
	}
}

func TestGetTemplate_NotFound(t *testing.T) {
	h, _ := setupTemplateHandler()
	r := setupTemplateRouter(h)

	w := httptest.NewRecorder()
	req, _ := http.NewRequest("GET", "/api/v1/templates/999", nil)
	r.ServeHTTP(w, req)

	if w.Code != http.StatusNotFound {
		t.Fatalf("expected 404, got %d: %s", w.Code, w.Body.String())
	}
}

func TestGetTemplate_InvalidID(t *testing.T) {
	h, _ := setupTemplateHandler()
	r := setupTemplateRouter(h)

	w := httptest.NewRecorder()
	req, _ := http.NewRequest("GET", "/api/v1/templates/abc", nil)
	r.ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Fatalf("expected 400, got %d: %s", w.Code, w.Body.String())
	}
}

func TestUpdateTemplate_Success(t *testing.T) {
	h, _ := setupTemplateHandler()
	r := setupTemplateRouter(h)

	// Seed data
	id, _ := h.store.Create(context.Background(), &model.CreateTemplateRequest{Name: "old", Script: "echo hi"})

	body := `{"name":"updated"}`
	w := httptest.NewRecorder()
	req, _ := http.NewRequest("PUT", "/api/v1/templates/"+itoa(id), bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	r.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}
	var resp server.APIResponse
	json.Unmarshal(w.Body.Bytes(), &resp)
	if !resp.Success {
		t.Fatalf("expected success=true, got: %s", w.Body.String())
	}
}

func TestDeleteTemplate_Success(t *testing.T) {
	h, _ := setupTemplateHandler()
	r := setupTemplateRouter(h)

	// Seed data
	id, _ := h.store.Create(context.Background(), &model.CreateTemplateRequest{Name: "to-delete", Script: "echo hi"})

	w := httptest.NewRecorder()
	req, _ := http.NewRequest("DELETE", "/api/v1/templates/"+itoa(id), nil)
	r.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}
	var resp server.APIResponse
	json.Unmarshal(w.Body.Bytes(), &resp)
	if !resp.Success {
		t.Fatalf("expected success=true, got: %s", w.Body.String())
	}
}

// itoa converts int64 to string for URL path construction.
func itoa(id int64) string {
	return fmt.Sprintf("%d", id)
}

func setupTemplateHandlerWithObserver() (*TemplateHandler, *gorm.DB, *observer.ObservedLogs) {
	core, recorded := observer.New(zapcore.DebugLevel)
	l := zap.New(core)
	db, _ := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{Logger: logger.Default.LogMode(logger.Silent)})
	db.AutoMigrate(&model.JobTemplate{})
	s := store.NewTemplateStore(db)
	return NewTemplateHandler(s, l), db, recorded
}

func TestTemplateLogging_CreateSuccess_LogsInfoWithID(t *testing.T) {
	h, _, recorded := setupTemplateHandlerWithObserver()
	r := setupTemplateRouter(h)

	body := `{"name":"log-tpl","script":"echo hi"}`
	w := httptest.NewRecorder()
	req, _ := http.NewRequest("POST", "/api/v1/templates", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	r.ServeHTTP(w, req)

	if w.Code != http.StatusCreated {
		t.Fatalf("expected 201, got %d: %s", w.Code, w.Body.String())
	}

	entries := recorded.FilterMessage("template created").FilterLevelExact(zapcore.InfoLevel).All()
	if len(entries) != 1 {
		t.Fatalf("expected 1 info log for 'template created', got %d", len(entries))
	}
	fields := entries[0].ContextMap()
	if fields["id"] == nil {
		t.Fatal("expected log entry to contain 'id' field")
	}
}

func TestTemplateLogging_UpdateSuccess_LogsInfoWithID(t *testing.T) {
	h, _, recorded := setupTemplateHandlerWithObserver()
	r := setupTemplateRouter(h)

	id, _ := h.store.Create(context.Background(), &model.CreateTemplateRequest{Name: "old", Script: "echo hi"})

	body := `{"name":"updated"}`
	w := httptest.NewRecorder()
	req, _ := http.NewRequest("PUT", "/api/v1/templates/"+itoa(id), bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	r.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}

	entries := recorded.FilterMessage("template updated").FilterLevelExact(zapcore.InfoLevel).All()
	if len(entries) != 1 {
		t.Fatalf("expected 1 info log for 'template updated', got %d", len(entries))
	}
	fields := entries[0].ContextMap()
	if fields["id"] == nil {
		t.Fatal("expected log entry to contain 'id' field")
	}
}

func TestTemplateLogging_DeleteSuccess_LogsInfoWithID(t *testing.T) {
	h, _, recorded := setupTemplateHandlerWithObserver()
	r := setupTemplateRouter(h)

	id, _ := h.store.Create(context.Background(), &model.CreateTemplateRequest{Name: "to-delete", Script: "echo hi"})

	w := httptest.NewRecorder()
	req, _ := http.NewRequest("DELETE", "/api/v1/templates/"+itoa(id), nil)
	r.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}

	entries := recorded.FilterMessage("template deleted").FilterLevelExact(zapcore.InfoLevel).All()
	if len(entries) != 1 {
		t.Fatalf("expected 1 info log for 'template deleted', got %d", len(entries))
	}
	fields := entries[0].ContextMap()
	if fields["id"] == nil {
		t.Fatal("expected log entry to contain 'id' field")
	}
}

func TestTemplateLogging_GetNotFound_LogsWarnWithID(t *testing.T) {
	h, _, recorded := setupTemplateHandlerWithObserver()
	r := setupTemplateRouter(h)

	w := httptest.NewRecorder()
	req, _ := http.NewRequest("GET", "/api/v1/templates/999", nil)
	r.ServeHTTP(w, req)

	if w.Code != http.StatusNotFound {
		t.Fatalf("expected 404, got %d: %s", w.Code, w.Body.String())
	}

	entries := recorded.FilterMessage("template not found").FilterLevelExact(zapcore.WarnLevel).All()
	if len(entries) != 1 {
		t.Fatalf("expected 1 warn log for 'template not found', got %d", len(entries))
	}
	fields := entries[0].ContextMap()
	if fields["id"] == nil {
		t.Fatal("expected log entry to contain 'id' field")
	}
}

func TestTemplateLogging_CreateBadRequest_LogsWarn(t *testing.T) {
	h, _, recorded := setupTemplateHandlerWithObserver()
	r := setupTemplateRouter(h)

	body := `{"name":"","script":""}`
	w := httptest.NewRecorder()
	req, _ := http.NewRequest("POST", "/api/v1/templates", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	r.ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Fatalf("expected 400, got %d: %s", w.Code, w.Body.String())
	}

	warnEntries := recorded.FilterLevelExact(zapcore.WarnLevel).All()
	if len(warnEntries) == 0 {
		t.Fatal("expected at least 1 warn log for bad request")
	}
}

func TestTemplateLogging_InvalidID_LogsWarn(t *testing.T) {
	h, _, recorded := setupTemplateHandlerWithObserver()
	r := setupTemplateRouter(h)

	w := httptest.NewRecorder()
	req, _ := http.NewRequest("GET", "/api/v1/templates/abc", nil)
	r.ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Fatalf("expected 400, got %d: %s", w.Code, w.Body.String())
	}

	warnEntries := recorded.FilterLevelExact(zapcore.WarnLevel).All()
	if len(warnEntries) == 0 {
		t.Fatal("expected at least 1 warn log for invalid id")
	}
}

func TestTemplateLogging_ListSuccess_NoInfoLog(t *testing.T) {
	h, _, recorded := setupTemplateHandlerWithObserver()
	r := setupTemplateRouter(h)

	// Seed data
	h.store.Create(context.Background(), &model.CreateTemplateRequest{Name: "test-tpl", Script: "echo hi"})

	// Reset recorded logs so the create log doesn't interfere
	recorded.TakeAll()

	w := httptest.NewRecorder()
	req, _ := http.NewRequest("GET", "/api/v1/templates", nil)
	r.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}

	infoEntries := recorded.FilterLevelExact(zapcore.InfoLevel).All()
	if len(infoEntries) != 0 {
		t.Fatalf("expected 0 info logs for list success, got %d: %+v", len(infoEntries), infoEntries)
	}
}

func TestTemplateLogging_LogsDoNotContainTemplateContent(t *testing.T) {
	h, _, recorded := setupTemplateHandlerWithObserver()
	r := setupTemplateRouter(h)

	body := `{"name":"secret-name","script":"secret-script","partition":"secret-partition"}`
	w := httptest.NewRecorder()
	req, _ := http.NewRequest("POST", "/api/v1/templates", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	r.ServeHTTP(w, req)

	if w.Code != http.StatusCreated {
		t.Fatalf("expected 201, got %d: %s", w.Code, w.Body.String())
	}

	entries := recorded.All()
	for _, e := range entries {
		logStr := e.Message + " " + fmt.Sprintf("%v", e.ContextMap())
		if strings.Contains(logStr, "secret-name") || strings.Contains(logStr, "secret-script") || strings.Contains(logStr, "secret-partition") {
			t.Fatalf("log entry contains sensitive template content: %s", logStr)
		}
	}
}