"""
Main entry point: builds a clash-free dummy schedule and renders all five
timetable views (batch/department/room/student/teacher -wise) as .xlsx
files under result/templates/<view>/.

Run:
    python app/template_generator.py
"""

import os
import shutil
import sys

APP_DIR = os.path.dirname(os.path.abspath(__file__))
ROOT_DIR = os.path.dirname(APP_DIR)

sys.path.insert(0, APP_DIR)
sys.path.insert(0, os.path.join(ROOT_DIR, "controller"))
sys.path.insert(0, os.path.join(ROOT_DIR, "templates", "batch-wise"))
sys.path.insert(0, os.path.join(ROOT_DIR, "templates", "department-wise"))
sys.path.insert(0, os.path.join(ROOT_DIR, "templates", "room-wise"))
sys.path.insert(0, os.path.join(ROOT_DIR, "templates", "student-wise"))
sys.path.insert(0, os.path.join(ROOT_DIR, "templates", "teacher-wise"))

from template_controller import load_data, Scheduler  # noqa: E402
from conflict_checker import check_all_conflicts  # noqa: E402
from conflict_checker.student_conflict_checker import format_student_conflicts  # noqa: E402
from conflict_checker.teacher_conflict_checker import format_teacher_conflicts  # noqa: E402
from template_logger import reset_log, log_error, log_info, log_warning  # noqa: E402

from batch_wise_template import generate_batch_wise_templates  # noqa: E402
from department_wise_template import generate_department_wise_templates  # noqa: E402
from room_wise_template import generate_room_wise_templates  # noqa: E402
from student_wise_template import generate_student_wise_templates  # noqa: E402
from teacher_wise_template import generate_teacher_wise_templates  # noqa: E402

RESULT_DIR = os.path.join(ROOT_DIR, "result", "templates")
VIEW_NAMES = ["batch-wise", "department-wise", "room-wise", "student-wise", "teacher-wise"]


def _check_and_log(sessions, label):
    """Runs student + teacher conflict checks over `sessions` and logs the result."""
    report = check_all_conflicts(sessions)
    if report["has_conflicts"]:
        for line in format_student_conflicts(report["student_conflicts"]):
            log_error(f"[{label}] STUDENT CONFLICT: {line}")
        for line in format_teacher_conflicts(report["teacher_conflicts"]):
            log_error(f"[{label}] TEACHER CONFLICT: {line}")
        log_warning(
            f"[{label}] Found {len(report['student_conflicts'])} student conflict(s) and "
            f"{len(report['teacher_conflicts'])} teacher conflict(s)."
        )
    else:
        log_info(f"[{label}] No conflicts found — clash-free.")
    return report


def clear_result_dir():
    """Removes every previous run's output so stale files never linger."""
    for view_name in VIEW_NAMES:
        output_dir = os.path.join(RESULT_DIR, view_name)
        if os.path.exists(output_dir):
            shutil.rmtree(output_dir)
        os.makedirs(output_dir, exist_ok=True)


def main():
    reset_log()
    clear_result_dir()

    data_csv_marker = os.path.join(ROOT_DIR, "data", "dummy", "blocks", "rooms.csv")
    if not os.path.exists(data_csv_marker):
        print("Dummy data not found — generating it first...")
        sys.path.insert(0, os.path.join(ROOT_DIR, "data", "dummy"))
        from generate_dummy_data import main as generate_dummy_data
        generate_dummy_data()
        print()

    log_info("Loading data...")
    data = load_data()
    scheduler = Scheduler(data)

    # --- Phase 1: general courses (Tue/Thu preferred), self-repaired until clash-free ---
    log_info("Phase 1/3: scheduling general courses...")
    phase1_sessions = scheduler.phase_1_general_courses()
    _check_and_log(phase1_sessions, "Phase 1 (general courses)")

    # --- Phase 2: labs, scheduled against Phase 1's fixed placements ---
    log_info("Phase 2/3: scheduling labs...")
    phase2_sessions = scheduler.phase_2_labs()
    _check_and_log(phase1_sessions + phase2_sessions, "Phase 2 (general courses + labs)")

    # --- Phase 3: remaining theory courses, batch by batch ---
    log_info("Phase 3/3: scheduling remaining courses (batch by batch)...")
    phase3_sessions = scheduler.phase_3_remaining_courses()

    sessions = phase1_sessions + phase2_sessions + phase3_sessions
    log_info(
        f"Scheduling complete: {len(phase1_sessions)} general, {len(phase2_sessions)} lab, "
        f"{len(phase3_sessions)} remaining = {len(sessions)} total session(s)."
    )

    log_info("Running final conflict check (student/batch and teacher) over the full schedule...")
    _check_and_log(sessions, "Final (full schedule)")

    generators = [
        ("batch-wise", generate_batch_wise_templates),
        ("department-wise", generate_department_wise_templates),
        ("room-wise", generate_room_wise_templates),
        ("student-wise", generate_student_wise_templates),
        ("teacher-wise", generate_teacher_wise_templates),
    ]

    total_files = 0
    for view_name, generate_fn in generators:
        output_dir = os.path.join(RESULT_DIR, view_name)
        written = generate_fn(sessions, data, output_dir)
        total_files += len(written)
        print(f"[{view_name}] generated {len(written)} file(s) -> {output_dir}")

    print(f"\nDone. {total_files} timetable file(s) written under {RESULT_DIR}")


if __name__ == "__main__":
    main()