package main

import (
	"errors"
	"net/http"
	"strings"
	"time"

	"github.com/go-chi/chi/v5"
)

func (a *app) getLearnerScormRuntime(w http.ResponseWriter, r *http.Request) {
	userID, ok := a.learnerSubjectFromContext(r)
	if !ok {
		writeError(w, http.StatusUnauthorized, "missing learner subject")
		return
	}
	courseID := strings.TrimSpace(chi.URLParam(r, "id"))
	course, enrollment, _, access, err := a.loadLearnerScormRuntimeContext(r, userID, courseID)
	if err != nil {
		a.writeLearningNotFound(w, err, "SCORM course")
		return
	}
	if allowed, _ := access["allowed"].(bool); !allowed {
		writeError(w, http.StatusForbidden, stringValue(access["message"]))
		return
	}
	scoID := strings.TrimSpace(r.URL.Query().Get("scoId"))
	if scoID == "" {
		scoID = firstScormSCOID(course)
	}
	if scoID == "" || !scormCourseHasSCO(course, scoID) {
		writeError(w, http.StatusNotFound, "SCORM SCO not found")
		return
	}
	states, err := a.list("scorm_runtime_states", Doc{"userId": userID, "courseId": courseID, "scoId": scoID}, Sort{{Key: "updatedAt", Value: -1}})
	if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to load SCORM runtime")
		return
	}
	if len(states) == 0 {
		writeJSON(w, http.StatusOK, defaultScormRuntimeState(userID, courseID, stringValue(enrollment["id"]), scoID))
		return
	}
	writeJSON(w, http.StatusOK, states[0])
}

func (a *app) commitLearnerScormRuntime(w http.ResponseWriter, r *http.Request) {
	userID, ok := a.learnerSubjectFromContext(r)
	if !ok {
		writeError(w, http.StatusUnauthorized, "missing learner subject")
		return
	}
	courseID := strings.TrimSpace(chi.URLParam(r, "id"))
	course, enrollment, _, access, err := a.loadLearnerScormRuntimeContext(r, userID, courseID)
	if err != nil {
		a.writeLearningNotFound(w, err, "SCORM course")
		return
	}
	if allowed, _ := access["allowed"].(bool); !allowed {
		writeError(w, http.StatusForbidden, stringValue(access["message"]))
		return
	}
	var body map[string]any
	if err := decodeJSON(r, &body); err != nil {
		writeError(w, http.StatusBadRequest, "invalid SCORM runtime payload")
		return
	}
	scoID := strings.TrimSpace(stringValue(body["scoId"]))
	if scoID == "" {
		scoID = firstScormSCOID(course)
	}
	if scoID == "" || !scormCourseHasSCO(course, scoID) {
		writeError(w, http.StatusBadRequest, "scoId must identify a SCO in this course")
		return
	}
	states, err := a.list("scorm_runtime_states", Doc{"userId": userID, "courseId": courseID, "scoId": scoID}, Sort{{Key: "updatedAt", Value: -1}})
	if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to load SCORM runtime")
		return
	}
	state := defaultScormRuntimeState(userID, courseID, stringValue(enrollment["id"]), scoID)
	var existingID string
	if len(states) > 0 {
		existingID = stringValue(states[0]["id"])
		for k, v := range states[0] {
			state[k] = v
		}
	}
	for _, field := range []string{"location", "suspendData", "lessonStatus", "completionStatus", "successStatus", "status"} {
		if value, ok := body[field].(string); ok {
			state[field] = strings.TrimSpace(value)
		}
	}
	for _, field := range []string{"score", "progress"} {
		if raw, exists := body[field]; exists {
			if value, ok := numericValue(raw); ok {
				if value < 0 {
					value = 0
				}
				if value > 100 {
					value = 100
				}
				state[field] = value
			}
		}
	}
	for _, field := range []string{"sessionTimeSeconds", "totalTimeSeconds"} {
		if raw, exists := body[field]; exists {
			if value, ok := numericValue(raw); ok {
				if value < 0 {
					value = 0
				}
				state[field] = int64(value)
			}
		}
	}
	if rawValues, exists := body["values"]; exists {
		values, ok := asMap(rawValues)
		if !ok {
			writeError(w, http.StatusBadRequest, "values must be an object")
			return
		}
		merged := Doc{}
		if existing, ok := asMap(state["values"]); ok {
			for k, v := range existing {
				merged[k] = v
			}
		}
		for k, v := range values {
			merged[k] = v
		}
		state["values"] = merged
	}
	state["lastCommittedAt"] = time.Now().UnixMilli()
	if tenantID := tenantIDForLearningRequest(r); tenantID != "" {
		state["tenantId"] = tenantID
	}
	delete(state, "id")
	delete(state, "createdAt")
	delete(state, "updatedAt")
	var saved Doc
	if existingID != "" {
		saved, err = a.patch("scorm_runtime_states", existingID, state)
	} else {
		saved, err = a.create("scorm_runtime_states", state)
	}
	if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to save SCORM runtime")
		return
	}
	summary, err := a.updateScormEnrollmentFromRuntime(course, enrollment, userID)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to update SCORM progress")
		return
	}
	writeJSON(w, http.StatusOK, Doc{"runtime": saved, "courseProgress": summary})
}

func defaultScormRuntimeState(userID, courseID, enrollmentID, scoID string) Doc {
	return Doc{
		"userId": userID,
		"courseId": courseID,
		"enrollmentId": enrollmentID,
		"scoId": scoID,
		"status": "initialized",
		"location": "",
		"suspendData": "",
		"lessonStatus": "incomplete",
		"completionStatus": "incomplete",
		"successStatus": "unknown",
		"score": 0,
		"progress": 0,
		"sessionTimeSeconds": 0,
		"totalTimeSeconds": 0,
		"values": Doc{},
	}
}

func (a *app) loadLearnerScormRuntimeContext(r *http.Request, userID, courseID string) (Doc, Doc, []Doc, Doc, error) {
	course, err := a.getByID("scorm_courses", courseID)
	if err != nil {
		return nil, nil, nil, nil, err
	}
	enrollments, err := a.list("enrollments", Doc{"userId": userID, "courseId": courseID}, Sort{{Key: "updatedAt", Value: -1}})
	if err != nil {
		return nil, nil, nil, nil, err
	}
	if len(enrollments) == 0 {
		return course, nil, nil, learnerAccessResult(false, "missing_enrollment", "You are not enrolled in this SCORM course."), nil
	}
	enrollment := enrollments[0]
	exports, err := a.list("scorm_exports", Doc{"courseId": courseID}, Sort{{Key: "createdAt", Value: -1}})
	if err != nil {
		return nil, nil, nil, nil, err
	}
	entitled, reason, message, err := a.learnerEntitlementDecision(r, userID, resolveEntitlementKey(course, nil))
	if err != nil {
		return nil, nil, nil, nil, err
	}
	return course, enrollment, exports, evaluateLearnerScormLaunch(course, enrollment, exports, entitled, reason, message), nil
}

func firstScormSCOID(course Doc) string {
	raw := course["scos"]
	switch list := raw.(type) {
	case []any:
		if len(list) > 0 {
			if item, ok := asMap(list[0]); ok {
				return stringValue(item["id"])
			}
		}
	case List:
		if len(list) > 0 {
			if item, ok := asMap(list[0]); ok {
				return stringValue(item["id"])
			}
		}
	}
	return ""
}

func scormCourseHasSCO(course Doc, scoID string) bool {
	raw := course["scos"]
	var list []any
	switch value := raw.(type) {
	case []any:
		list = value
	case List:
		list = []any(value)
	}
	for _, rawItem := range list {
		item, ok := asMap(rawItem)
		if ok && stringValue(item["id"]) == scoID {
			return true
		}
	}
	return false
}

func scormRuntimeComplete(state Doc) bool {
	completion := strings.ToLower(strings.TrimSpace(stringValue(state["completionStatus"])))
	lesson := strings.ToLower(strings.TrimSpace(stringValue(state["lessonStatus"])))
	return completion == "completed" || completion == "passed" || lesson == "completed" || lesson == "passed" || lesson == "failed"
}

func (a *app) updateScormEnrollmentFromRuntime(course, enrollment Doc, userID string) (Doc, error) {
	courseID := stringValue(course["id"])
	states, err := a.list("scorm_runtime_states", Doc{"courseId": courseID, "userId": userID}, nil)
	if err != nil {
		return nil, err
	}
	total := 0
	switch scos := course["scos"].(type) {
	case []any:
		total = len(scos)
	case List:
		total = len(scos)
	}
	completed := 0
	scoreTotal := 0.0
	scoreCount := 0
	for _, state := range states {
		if scormRuntimeComplete(state) {
			completed++
		}
		if score, ok := numericValue(state["score"]); ok && score > 0 {
			scoreTotal += score
			scoreCount++
		}
	}
	percent := 0.0
	if total > 0 {
		percent = float64(completed) * 100 / float64(total)
	}
	patch := Doc{"progress": percent}
	if scoreCount > 0 {
		patch["score"] = scoreTotal / float64(scoreCount)
	}
	if total > 0 && completed >= total {
		patch["status"] = "completed"
		patch["completedAt"] = time.Now().UnixMilli()
	} else if percent > 0 {
		patch["status"] = "in_progress"
	}
	if enrollment != nil && stringValue(enrollment["id"]) != "" {
		if _, err := a.patch("enrollments", stringValue(enrollment["id"]), patch); err != nil && !errors.Is(err, ErrNotFound) {
			return nil, err
		}
	}
	return Doc{"total": total, "completed": completed, "percent": percent, "score": patch["score"]}, nil
}