"""API methods for the LMS.
"""

import frappe

@frappe.whitelist()
def autosave_section(section, code):
    """Saves the code edited in one of the sections.
    """
    doc = frappe.get_doc(
        doctype="Code Revision",
        section=section,
        code=code,
        author=frappe.session.user)
    doc.insert()
    return {"name": doc.name}

@frappe.whitelist()
def submit_solution(exercise, code):
    """Submits a solution.

    @exerecise: name of the exercise to submit
    @code: solution to the exercise
    """
    ex = frappe.get_doc("Exercise", exercise)
    if not ex:
        return
    doc = ex.submit(code)
    return {"name": doc.name, "creation": doc.creation}

@frappe.whitelist()
def save_current_lesson(course_name, lesson_name):
    """Saves the current lesson for a student/mentor.
    """
    name = frappe.get_value(
        doctype="LMS Batch Membership",
        filters={
            "course": course_name,
            "member": frappe.session.user
        },
        fieldname="name")
    if not name:
        return
    doc = frappe.get_doc("LMS Batch Membership", name)
    doc.current_lesson = lesson_name
    doc.save(ignore_permissions=True)
    return {"current_lesson": doc.current_lesson}


@frappe.whitelist()
def join_cohort(course, cohort, subgroup, invite_code):
    """Creates a Cohort Join Request for given user.
    """
    course_doc = frappe.get_doc("LMS Course", course)
    cohort_doc = course_doc and course_doc.get_cohort(cohort)
    subgroup_doc = cohort_doc and cohort_doc.get_subgroup(subgroup)

    if not subgroup_doc or subgroup_doc.invite_code != invite_code:
        return {
            "ok": False,
            "error": "Invalid join link"
        }

    data = {
        "doctype": "Cohort Join Request",
        "cohort": cohort_doc.name,
        "subgroup": subgroup_doc.name,
        "email": frappe.session.user,
        "status": "Pending"
    }
    # Don't insert duplicate records
    if frappe.db.exists(data):
        return {"ok": True, "status": "record found"}
    else:
        doc = frappe.get_doc(data)
        doc.insert(ignore_permissions=True)
        return {"ok": True, "status": "record created"}

@frappe.whitelist()
def approve_cohort_join_request(join_request):
    r = frappe.get_doc("Cohort Join Request", join_request)
    sg = r and frappe.get_doc("Cohort Subgroup", r.subgroup)
    if not sg or r.status not in ["Pending", "Accepted"]:
        return {
            "ok": False,
            "error": "Invalid Join Request"
        }
    if not sg.is_manager(frappe.session.user) and "System Manager" not in frappe.get_roles():
        return {
            "ok": False,
            "error": "Permission Deined"
        }

    r.status = "Accepted"
    r.save(ignore_permissions=True)
    return {"ok": True}

@frappe.whitelist()
def reject_cohort_join_request(join_request):
    r = frappe.get_doc("Cohort Join Request", join_request)
    sg = r and frappe.get_doc("Cohort Subgroup", r.subgroup)
    if not sg or r.status not in ["Pending", "Rejected"]:
        return {
            "ok": False,
            "error": "Invalid Join Request"
        }
    if not sg.is_manager(frappe.session.user) and "System Manager" not in frappe.get_roles():
        return {
            "ok": False,
            "error": "Permission Deined"
        }

    r.status = "Rejected"
    r.save(ignore_permissions=True)
    return {"ok": True}


@frappe.whitelist()
def undo_reject_cohort_join_request(join_request):
    r = frappe.get_doc("Cohort Join Request", join_request)
    sg = r and frappe.get_doc("Cohort Subgroup", r.subgroup)
    # keeping Pending as well to consider the case of duplicate requests
    if not sg or r.status not in ["Pending", "Rejected"]:
        return {
            "ok": False,
            "error": "Invalid Join Request"
        }
    if not sg.is_manager(frappe.session.user) and "System Manager" not in frappe.get_roles():
        return {
            "ok": False,
            "error": "Permission Deined"
        }

    r.status = "Pending"
    r.save(ignore_permissions=True)
    return {"ok": True}

@frappe.whitelist()
def add_mentor_to_subgroup(subgroup, email):
    try:
        sg = frappe.get_doc("Cohort Subgroup", subgroup)
    except frappe.DoesNotExistError:
        return {
            "ok": False,
            "error": f"Invalid subgroup: {subgroup}"
        }

    if not sg.get_cohort().is_admin(frappe.session.user) and "System Manager" not in frappe.get_roles():
        return {
            "ok": False,
            "error": "Permission Deined"
        }

    try:
        user = frappe.get_doc("User", email)
    except frappe.DoesNotExistError:
        return {
            "ok": False,
            "error": f"Invalid user: {email}"
        }

    sg.add_mentor(email)
    return {"ok": True}