package handlers

import (
	"net/http"

	"github.com/breakpilot/school-service/internal/models"
	"github.com/gin-gonic/gin"
)

// CreateExam creates a new exam
func (h *Handler) CreateExam(c *gin.Context) {
	teacherID := getUserID(c)
	if teacherID == "" {
		respondError(c, http.StatusUnauthorized, "User not authenticated")
		return
	}

	var req models.CreateExamRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		respondError(c, http.StatusBadRequest, "Invalid request: "+err.Error())
		return
	}

	exam, err := h.examService.CreateExam(c.Request.Context(), teacherID, &req)
	if err != nil {
		respondError(c, http.StatusInternalServerError, "Failed to create exam: "+err.Error())
		return
	}

	respondCreated(c, exam)
}

// GetExams returns all exams for the current teacher
func (h *Handler) GetExams(c *gin.Context) {
	teacherID := getUserID(c)
	if teacherID == "" {
		respondError(c, http.StatusUnauthorized, "User not authenticated")
		return
	}

	exams, err := h.examService.GetExams(c.Request.Context(), teacherID)
	if err != nil {
		respondError(c, http.StatusInternalServerError, "Failed to get exams: "+err.Error())
		return
	}

	respondSuccess(c, exams)
}

// GetExam returns a single exam
func (h *Handler) GetExam(c *gin.Context) {
	teacherID := getUserID(c)
	examID := c.Param("id")

	if teacherID == "" {
		respondError(c, http.StatusUnauthorized, "User not authenticated")
		return
	}

	exam, err := h.examService.GetExam(c.Request.Context(), examID, teacherID)
	if err != nil {
		respondError(c, http.StatusNotFound, "Exam not found")
		return
	}

	respondSuccess(c, exam)
}

// UpdateExam updates an exam
func (h *Handler) UpdateExam(c *gin.Context) {
	teacherID := getUserID(c)
	examID := c.Param("id")

	if teacherID == "" {
		respondError(c, http.StatusUnauthorized, "User not authenticated")
		return
	}

	var req models.CreateExamRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		respondError(c, http.StatusBadRequest, "Invalid request: "+err.Error())
		return
	}

	exam, err := h.examService.UpdateExam(c.Request.Context(), examID, teacherID, &req)
	if err != nil {
		respondError(c, http.StatusInternalServerError, "Failed to update exam: "+err.Error())
		return
	}

	respondSuccess(c, exam)
}

// DeleteExam deletes an exam
func (h *Handler) DeleteExam(c *gin.Context) {
	teacherID := getUserID(c)
	examID := c.Param("id")

	if teacherID == "" {
		respondError(c, http.StatusUnauthorized, "User not authenticated")
		return
	}

	if err := h.examService.DeleteExam(c.Request.Context(), examID, teacherID); err != nil {
		respondError(c, http.StatusInternalServerError, "Failed to delete exam: "+err.Error())
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "Exam deleted"})
}

// GenerateExamVariant generates a variant of an exam using AI
func (h *Handler) GenerateExamVariant(c *gin.Context) {
	teacherID := getUserID(c)
	examID := c.Param("id")

	if teacherID == "" {
		respondError(c, http.StatusUnauthorized, "User not authenticated")
		return
	}

	var req models.GenerateExamVariantRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		respondError(c, http.StatusBadRequest, "Invalid request: "+err.Error())
		return
	}

	// Get the original exam
	originalExam, err := h.examService.GetExam(c.Request.Context(), examID, teacherID)
	if err != nil {
		respondError(c, http.StatusNotFound, "Original exam not found")
		return
	}

	// Generate variant content using AI
	newContent, err := h.aiService.GenerateExamVariant(c.Request.Context(), originalExam.Content, req.VariationType)
	if err != nil {
		respondError(c, http.StatusInternalServerError, "Failed to generate variant: "+err.Error())
		return
	}

	// Create the variant exam
	variant, err := h.examService.CreateExamVariant(c.Request.Context(), examID, teacherID, newContent, req.VariationType)
	if err != nil {
		respondError(c, http.StatusInternalServerError, "Failed to save variant: "+err.Error())
		return
	}

	respondCreated(c, variant)
}

// SaveExamResults saves results for students
func (h *Handler) SaveExamResults(c *gin.Context) {
	examID := c.Param("id")

	var req models.UpdateExamResultRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		respondError(c, http.StatusBadRequest, "Invalid request: "+err.Error())
		return
	}

	result, err := h.examService.SaveExamResult(c.Request.Context(), examID, &req)
	if err != nil {
		respondError(c, http.StatusInternalServerError, "Failed to save result: "+err.Error())
		return
	}

	respondSuccess(c, result)
}

// GetExamResults returns all results for an exam
func (h *Handler) GetExamResults(c *gin.Context) {
	examID := c.Param("id")

	results, err := h.examService.GetExamResults(c.Request.Context(), examID)
	if err != nil {
		respondError(c, http.StatusInternalServerError, "Failed to get results: "+err.Error())
		return
	}

	respondSuccess(c, results)
}

// ApproveExamResult approves a result for grade transfer
func (h *Handler) ApproveExamResult(c *gin.Context) {
	examID := c.Param("id")
	studentID := c.Param("studentId")

	if err := h.examService.ApproveExamResult(c.Request.Context(), examID, studentID); err != nil {
		respondError(c, http.StatusInternalServerError, "Failed to approve result: "+err.Error())
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "Result approved"})
}

// GetStudentsNeedingRewrite returns students who need to rewrite
func (h *Handler) GetStudentsNeedingRewrite(c *gin.Context) {
	examID := c.Param("id")

	students, err := h.examService.GetStudentsNeedingRewrite(c.Request.Context(), examID)
	if err != nil {
		respondError(c, http.StatusInternalServerError, "Failed to get students: "+err.Error())
		return
	}

	respondSuccess(c, students)
}