from flask import Blueprint, render_template, redirect, url_for, flash, request, jsonify
from jinja2_fragments import render_block
from werkzeug.security import generate_password_hash, check_password_hash
from flask_login import current_user, login_required
from extensions import db, htmx, environment
from datetime import datetime, timezone, timedelta
import json

'''
CREATE TABLE timer_functions (
    id               SERIAL PRIMARY KEY,
    name             TEXT NOT NULL,
    code             TEXT NOT NULL,
    environment      JSONB NOT NULL DEFAULT '{}'::jsonb,
    version_number   INT NOT NULL DEFAULT 1,

    user_id          INT NOT NULL,  -- the referencing column

    trigger_type     VARCHAR(20) NOT NULL CHECK (
                        trigger_type IN ('interval', 'date')
                     ),
    frequency_minutes INT,       -- used if trigger_type = 'interval'
    run_date          TIMESTAMPTZ, -- used if trigger_type = 'date' (one-off)

    next_run          TIMESTAMPTZ,
    last_run          TIMESTAMPTZ,
    enabled           BOOLEAN NOT NULL DEFAULT TRUE,
    invocation_count INT NOT NULL DEFAULT 0,

    -- Define the foreign key constraint
    CONSTRAINT fk_timer_functions_user
        FOREIGN KEY (user_id)
        REFERENCES users (id)
        ON DELETE CASCADE
        ON UPDATE CASCADE
);

CREATE TABLE timer_function_versions (
    id SERIAL PRIMARY KEY,
    timer_function_id INT NOT NULL,
    script TEXT NOT NULL,
    version_number INT NOT NULL,
    versioned_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),

    CONSTRAINT fk_timer_function_versions
        FOREIGN KEY (timer_function_id)
        REFERENCES timer_functions (id)
        ON DELETE CASCADE
        ON UPDATE CASCADE
);

CREATE OR REPLACE FUNCTION fn_timer_functions_versioning()
RETURNS TRIGGER
LANGUAGE plpgsql
AS $$
DECLARE
    next_version INT;
BEGIN
    IF TG_OP = 'INSERT' THEN
        -- In an AFTER INSERT, the row already has been inserted with version_number default (1).
        -- We can optionally override that or ensure an initial version is recorded:
        INSERT INTO timer_function_versions (timer_function_id, script, version_number)
        VALUES (NEW.id, NEW.code, 1);

        -- If desired, ensure timer_functions.version_number is set explicitly:
        UPDATE timer_functions
           SET version_number = 1
         WHERE id = NEW.id;

        RETURN NEW;

    ELSIF TG_OP = 'UPDATE' THEN
        -- Only version if the 'code' changed
        IF NEW.code IS DISTINCT FROM OLD.code THEN
            -- Determine the next version number based on existing versions
            SELECT COALESCE(MAX(version_number), 0) + 1
              INTO next_version
              FROM timer_function_versions
             WHERE timer_function_id = NEW.id;

            -- Insert new version record
            INSERT INTO timer_function_versions (timer_function_id, script, version_number)
            VALUES (NEW.id, NEW.code, next_version);

            -- Manually update timer_functions to set version_number
            -- This second UPDATE will cause the trigger to fire again,
            -- but because code won't change, the trigger won't do another version bump.
            UPDATE timer_functions
               SET version_number = next_version
             WHERE id = NEW.id;
        END IF;

        RETURN NEW;
    END IF;

    RETURN NEW;
END;
$$;

CREATE TRIGGER tr_timer_functions_versioning
AFTER INSERT OR UPDATE
ON timer_functions
FOR EACH ROW
EXECUTE PROCEDURE fn_timer_functions_versioning();

CREATE TABLE timer_function_invocations (
    id SERIAL PRIMARY KEY,
    timer_function_id INT NOT NULL,
    status TEXT,
    invocation_time TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    logs JSONB,
    version_number INT NOT NULL,

    CONSTRAINT fk_timer_function_invocations
        FOREIGN KEY (timer_function_id)
        REFERENCES timer_functions (id)
        ON DELETE CASCADE
);

CREATE OR REPLACE FUNCTION fn_increment_invocation_count()
RETURNS TRIGGER
LANGUAGE plpgsql
AS $$
BEGIN
    UPDATE timer_functions
       SET invocation_count = invocation_count + 1
     WHERE id = NEW.timer_function_id;

    RETURN NEW;
END;
$$;

CREATE TRIGGER tr_increment_invocation_count
AFTER INSERT ON timer_function_invocations
FOR EACH ROW
EXECUTE PROCEDURE fn_increment_invocation_count();
'''

DEFAULT_SCRIPT = """async (req) => {
    environment.count += 1
    console.log(`Executing ${environment.count}`)
}"""

DEFAULT_ENVIRONMENT = """{
    "count": 0
}"""

timer = Blueprint('timer', __name__)

@timer.route('/overview')
@login_required
def overview():
    timer_functions = db.execute("""
        SELECT id, name, code, environment, trigger_type, 
               frequency_minutes, run_date, next_run, 
               last_run, enabled
        FROM timer_functions 
        WHERE user_id = %s
        ORDER BY id DESC
    """, [current_user.id])

    if htmx:
        return render_block(environment, 'dashboard/timer_functions/overview.html', 'page', timer_functions=timer_functions)
    return render_template('dashboard/timer_functions/overview.html', timer_functions=timer_functions)

@timer.route('/new', methods=['GET', 'POST'])
@login_required
def new():
    if request.method == 'GET':
        args = {
            'name': 'foo',
            'script': DEFAULT_SCRIPT,
            'environment_info': DEFAULT_ENVIRONMENT,
            'user_id': current_user.id
        }
        if htmx:
            return render_block(environment, 'dashboard/timer_functions/new.html', 'page', **args)
        return render_template('dashboard/timer_functions/new.html', **args)
    
    # Handle POST request
    try:
        data = request.json
        trigger_type = data.get('trigger_type')
        
        # Validate trigger type
        if trigger_type not in ('interval', 'date'):
            return jsonify({
                "status": "error",
                "message": "Invalid trigger type"
            }), 400
        
        # Calculate next_run based on trigger type
        next_run = None
        if trigger_type == 'interval':
            frequency_minutes = int(data.get('frequency_minutes'))
            next_run = datetime.now(timezone.utc) + timedelta(minutes=frequency_minutes)
        elif trigger_type == 'date':
            run_date = datetime.fromisoformat(data.get('run_date'))
            next_run = run_date
        
        # Insert new timer function
        db.execute("""
            INSERT INTO timer_functions 
                (name, code, environment, user_id, trigger_type, 
                 frequency_minutes, run_date, next_run, enabled)
            VALUES (%s, %s, %s::jsonb, %s, %s, %s, %s, %s, %s)
            RETURNING id
        """, [
            data.get('name'),
            data.get('script_content'),
            data.get('environment_info'),
            current_user.id,
            trigger_type,
            frequency_minutes if trigger_type == 'interval' else None,
            run_date if trigger_type == 'date' else None,
            next_run,
            True
        ],
        commit=True)
        
        return jsonify({
            "status": "success",
            "message": "Timer function created successfully"
        }), 200
        
    except Exception as e:
        return jsonify({
            "status": "error",
            "message": f"Error creating timer function: {str(e)}"
        }), 400

@timer.route('/edit/<int:function_id>', methods=['GET', 'POST'])
@login_required
def edit(function_id):
    if request.method == 'GET':
        # Fetch the timer function
        timer_function = db.execute("""
            SELECT id, name, code, environment, version_number, trigger_type, 
                   frequency_minutes, run_date, next_run, 
                   last_run, enabled
            FROM timer_functions 
            WHERE id = %s AND user_id = %s
        """, [function_id, current_user.id], one=True)

        if not timer_function:
            return jsonify({
                "status": "error",
                "message": "Timer function not found"
            }), 404
        
        # Format the environment JSON with indentation
        timer_function['environment'] = json.dumps(timer_function['environment'], indent=2)
        
        args = {
            'function_id': function_id,
            'timer_function': timer_function
        }

        if htmx:
            return render_block(environment, 'dashboard/timer_functions/edit.html', 'page', **args)
        return render_template('dashboard/timer_functions/edit.html', **args)
    
    # Handle POST request
    try:
        data = request.json
        trigger_type = data.get('trigger_type')
        
        # Validate trigger type
        if trigger_type not in ('interval', 'date'):
            return jsonify({
                "status": "error",
                "message": "Invalid trigger type"
            }), 400
        
        # Calculate next_run based on trigger type
        next_run = None
        if trigger_type == 'interval':
            frequency_minutes = int(data.get('frequency_minutes'))
            next_run = datetime.now(timezone.utc) + timedelta(minutes=frequency_minutes)
        elif trigger_type == 'date':
            run_date = datetime.fromisoformat(data.get('run_date'))
            next_run = run_date
        
        # Update timer function
        db.execute("""
            UPDATE timer_functions 
            SET name = %s,
                code = %s,
                environment = %s::jsonb,
                trigger_type = %s,
                frequency_minutes = %s,
                run_date = %s,
                next_run = %s,
                enabled = %s
            WHERE id = %s AND user_id = %s
            RETURNING id
        """, [
            data.get('name'),
            data.get('script_content'),
            data.get('environment_info'),
            trigger_type,
            frequency_minutes if trigger_type == 'interval' else None,
            run_date if trigger_type == 'date' else None,
            next_run,
            data.get('is_enabled', True),  # Default to True if not provided
            function_id,
            current_user.id
        ],
        commit=True)
        
        return jsonify({
            "status": "success",
            "message": "Timer function updated successfully"
        }), 200
        
    except Exception as e:
        return jsonify({
            "status": "error",
            "message": f"Error updating timer function: {str(e)}"
        }), 400

@timer.route('/delete/<int:function_id>', methods=['DELETE'])
@login_required
def delete(function_id):
    try:
        # Delete the timer function, but only if it belongs to the current user
        result = db.execute("""
            DELETE FROM timer_functions 
            WHERE id = %s AND user_id = %s
            RETURNING id
        """, [function_id, current_user.id], commit=True)
        
        if not result:
            return jsonify({
                "status": "error",
                "message": "Timer function not found or unauthorized"
            }), 404
        
        return jsonify({
            "status": "success",
            "message": "Timer function deleted successfully"
        }), 200
        
    except Exception as e:
        return jsonify({
            "status": "error",
            "message": f"Error deleting timer function: {str(e)}"
        }), 400

@timer.route('/toggle/<int:function_id>', methods=['POST'])
@login_required
def toggle(function_id):
    try:
        # Toggle the enabled status
        result = db.execute("""
            UPDATE timer_functions 
            SET enabled = NOT enabled
            WHERE id = %s AND user_id = %s
            RETURNING enabled
        """, [function_id, current_user.id], commit=True, one=True)
        
        if not result:
            return jsonify({
                "status": "error",
                "message": "Timer function not found or unauthorized"
            }), 404

        # Fetch updated timer functions for the overview template
        timer_functions = db.execute("""
            SELECT id, name, code, environment, trigger_type, 
                   frequency_minutes, run_date, next_run, 
                   last_run, enabled
            FROM timer_functions 
            WHERE user_id = %s
            ORDER BY id DESC
        """, [current_user.id])

        if htmx:
            return render_block(environment, 'dashboard/timer_functions/overview.html', 'page', 
                              timer_functions=timer_functions)
        return render_template('dashboard/timer_functions/overview.html', timer_functions=timer_functions)
        
    except Exception as e:
        return jsonify({
            "status": "error",
            "message": f"Error toggling timer function: {str(e)}"
        }), 400

@timer.route('/logs/<int:function_id>')
@login_required
def logs(function_id):
    # Fetch the timer function to verify ownership
    timer_function = db.execute("""
        SELECT id, name 
        FROM timer_functions 
        WHERE id = %s AND user_id = %s
    """, [function_id, current_user.id], one=True)

    if not timer_function:
        flash('Timer function not found', 'error')
        return redirect(url_for('timer.overview'))

    # Fetch the invocation logs
    timer_function_invocations = db.execute("""
        SELECT id, timer_function_id, status, invocation_time, 
               logs, version_number
        FROM timer_function_invocations 
        WHERE timer_function_id = %s
        ORDER BY invocation_time DESC
        LIMIT 100
    """, [function_id])

    args = {
        'user_id': current_user.id,
        'function_id': function_id,
        'timer_function_invocations': timer_function_invocations
    }

    if htmx:
        return render_block(environment, 'dashboard/timer_functions/logs.html', 'page', **args)
    return render_template('dashboard/timer_functions/logs.html', **args)

@timer.route('/history/<int:function_id>')
@login_required
def history(function_id):
    # Fetch the timer function to verify ownership
    timer_function = db.execute("""
        SELECT id, name, code, version_number
        FROM timer_functions 
        WHERE id = %s AND user_id = %s
    """, [function_id, current_user.id], one=True)

    if not timer_function:
        flash('Timer function not found', 'error')
        return redirect(url_for('timer.overview'))

    # Fetch all versions
    versions = db.execute("""
        SELECT version_number, script, versioned_at
        FROM timer_function_versions
        WHERE timer_function_id = %s
        ORDER BY version_number DESC
    """, [function_id])

    # Convert datetime objects to ISO format strings
    for version in versions:
        version['versioned_at'] = version['versioned_at'].isoformat() if version['versioned_at'] else None

    args = {
        'user_id': current_user.id,
        'function_id': function_id,
        'timer_function': timer_function,
        'versions': versions
    }

    if htmx:
        return render_block(environment, 'dashboard/timer_functions/history.html', 'page', **args)
    return render_template('dashboard/timer_functions/history.html', **args)