"""Phase 7: Integration formatters and setup guides.

Each integration has:
  - A formatter function: (submission, site, field_config, destination) -> (url, headers, body, method)
  - A setup guide: config_fields, steps, requires_url
"""

import json
import bleach
from datetime import datetime, timezone


# ─── Formatter functions ────────────────────────────────────────────────────────

def format_webhook(submission, site, field_config, destination):
    """Generic webhook — sends all submission data as JSON."""
    from app.services.form_logic import evaluate_all_conditions

    payload = {
        "event": "submission",
        "site_id": site["id"],
        "site_name": site["name"],
        "submission_id": submission["id"],
        "submitted_at": submission.get("submitted_at", ""),
        "fields": _build_flat_fields(submission, field_config),
    }

    # Add field metadata with conditional info
    if field_config:
        fields = _build_flat_fields(submission, field_config)
        metadata = evaluate_all_conditions(field_config, fields)
        if metadata:
            payload["field_metadata"] = {
                "visible_fields": metadata.get("visible_fields", {}),
                "computed_fields": metadata.get("computed_fields", {}),
                "applied_conditions": metadata.get("applied_conditions", []),
            }

    return {
        "url": destination["url"],
        "headers": {"Content-Type": "application/json"},
        "body": json.dumps(payload),
        "method": "POST",
    }


def format_google_sheets(submission, site, field_config, destination):
    """Google Sheets via Apps Script Web App.

    Expects destination.url = Apps Script deployment URL.
    Optionally config.sheet_name for the target sheet.

    Sends a JSON array of values (one row) that the Apps Script doPost
    can parse and append.
    """
    config = destination.get("config") or {}
    fields = _build_flat_fields(submission, field_config)
    sheet_name = config.get("sheet_name") or "Sheet1"

    # Header row on first delivery, then data row
    payload = {
        "sheet": sheet_name,
        "headers": list(fields.keys()),
        "values": list(fields.values()),
        "submitted_at": submission.get("submitted_at", ""),
    }
    return {
        "url": destination["url"],
        "headers": {"Content-Type": "application/json"},
        "body": json.dumps(payload),
        "method": "POST",
    }


def format_slack(submission, site, field_config, destination):
    """Slack Incoming Webhook.

    Sends a formatted block message with fields as key-value pairs.
    """
    config = destination.get("config") or {}
    fields = _build_flat_fields(submission, field_config)
    form_label = config.get("form_label") or site["name"]

    # Build blocks — first a header, then field sections
    fields_block = []
    for key, val in fields.items():
        if val:
            label = key.replace("_", " ").title()
            fields_block.append({
                "type": "section",
                "fields": [
                    {"type": "mrkdwn", "text": f"*{label}*\n"},
                    {"type": "mrkdwn", "text": f"{_slack_escape(str(val))}\n"},
                ],
            })

    payload = {
        "text": f"New form submission from {form_label}",
        "blocks": [
            {
                "type": "header",
                "text": {"type": "plain_text", "text": f"📋 {form_label}"},
            },
            *fields_block,
            {
                "type": "context",
                "elements": [
                    {
                        "type": "mrkdwn",
                        "text": f"Submitted at {_slack_escape(submission.get('submitted_at', ''))}",
                    }
                ],
            },
        ],
    }
    return {
        "url": destination["url"],
        "headers": {"Content-Type": "application/json"},
        "body": json.dumps(payload),
        "method": "POST",
    }


def format_discord(submission, site, field_config, destination):
    """Discord Webhook.

    Sends an embed with fields as Discord embed fields.
    """
    config = destination.get("config") or {}
    fields = _build_flat_fields(submission, field_config)

    # Discord embed fields have 25-char name limit and 1024-char value limit
    embed_fields = []
    for key, val in fields.items():
        if val:
            label = key.replace("_", " ").title()[:25]
            value = str(val)[:1024] or "\u200b"  # zero-width space for empty
            embed_fields.append({"name": label, "value": value, "inline": True})

    # Discord embed max 25 fields — truncate if needed
    embed_fields = embed_fields[:25]

    payload = {
        "username": config.get("username") or "AgentForms",
        "embeds": [
            {
                "title": site["name"],
                "description": f"New form submission — {submission.get('submitted_at', '')}",
                "color": 3447003,  # blue
                "fields": embed_fields,
                "footer": {"text": f"AgentForms • Submission #{submission.get('id', '?')}"},
                "timestamp": datetime.now(timezone.utc).isoformat(),
            }
        ],
    }
    return {
        "url": destination["url"],
        "headers": {"Content-Type": "application/json"},
        "body": json.dumps(payload),
        "method": "POST",
    }


def format_telegram(submission, site, field_config, destination):
    """Telegram Bot API.

    Sends a formatted message to the configured chat.
    Expects config.bot_token and config.chat_id.
    """
    config = destination.get("config") or {}
    bot_token = config.get("bot_token") or ""
    chat_id = config.get("chat_id") or ""
    fields = _build_flat_fields(submission, field_config)

    # Build HTML-formatted message
    lines = [f"<b>📋 {site['name']}</b>\n"]
    for key, val in fields.items():
        if val:
            label = key.replace("_", " ").title()
            lines.append(f"<b>{_tg_escape(label)}:</b> {_tg_escape(str(val))}")

    lines.append(f"\n<i>{_tg_escape(submission.get('submitted_at', ''))}</i>")
    text = "\n".join(lines)

    # Telegram 4096 char limit
    text = text[:4096]

    # Build the API URL from config
    url = f"https://api.telegram.org/bot{bot_token}/sendMessage"
    payload = {
        "chat_id": chat_id,
        "text": text,
        "parse_mode": "HTML",
    }
    return {
        "url": url,
        "headers": {"Content-Type": "application/json"},
        "body": json.dumps(payload),
        "method": "POST",
    }


def format_airtable(submission, site, field_config, destination):
    """Airtable API — create record.

    Expects destination.url = https://api.airtable.com/v0/{BASE_ID}/{TABLE_NAME}
    config.api_key for Bearer token.
    """
    config = destination.get("config") or {}
    api_key = config.get("api_key") or ""
    fields = _build_flat_fields(submission, field_config)

    payload = {"fields": fields}
    return {
        "url": destination["url"],
        "headers": {
            "Content-Type": "application/json",
            "Authorization": f"Bearer {api_key}",
        },
        "body": json.dumps(payload),
        "method": "POST",
    }


def format_notion(submission, site, field_config, destination):
    """Notion API — append blocks to a page.

    Expects destination.url = https://api.notion.com/v1/blocks/{BLOCK_ID}/children
    config.api_key for Bearer token.
    """
    config = destination.get("config") or {}
    api_key = config.get("api_key") or ""
    fields = _build_flat_fields(submission, field_config)

    # Build paragraph blocks for each field
    children = []
    # Header
    children.append({
        "object": "block",
        "heading_2": {
            "rich_text": [
                {
                    "type": "text",
                    "text": {"content": f"Submission from {site['name']}"},
                }
            ],
        },
    })

    # Divider
    children.append({
        "object": "block",
        "divider": {},
    })

    # Fields as bullet points
    for key, val in fields.items():
        if val:
            label = key.replace("_", " ").title()
            children.append({
                "object": "block",
                "paragraph": {
                    "rich_text": [
                        {"type": "text", "text": {"content": f"{label}: "}, "annotations": {"bold": True}},
                        {"type": "text", "text": {"content": str(val)}},
                    ],
                },
            })

    # Timestamp
    children.append({
        "object": "block",
        "paragraph": {
            "rich_text": [
                {
                    "type": "text",
                    "text": {"content": f"Submitted at {submission.get('submitted_at', '')}"},
                    "annotations": {"italic": True},
                }
            ],
        },
    })

    payload = {"children": children}
    return {
        "url": destination["url"],
        "headers": {
            "Content-Type": "application/json",
            "Authorization": f"Bearer {api_key}",
            "Notion-Version": "2022-06-28",
        },
        "body": json.dumps(payload),
        "method": "POST",
    }


# ─── Formatter registry ───────────────────────────────────────────────────────

FORMATTERS = {
    "webhook": format_webhook,
    "google_sheets": format_google_sheets,
    "slack": format_slack,
    "discord": format_discord,
    "telegram": format_telegram,
    "airtable": format_airtable,
    "notion": format_notion,
}


# ─── Setup guides ─────────────────────────────────────────────────────────────

SETUP_GUIDES = {
    "webhook": {
        "config_fields": [],
        "requires_url": True,
        "steps": [
            "Provide the full URL where you want to receive form submissions.",
            "Your endpoint will receive a POST request with JSON payload on every submission.",
            "Payload includes: event, site_id, site_name, submission_id, submitted_at, fields.",
        ],
    },
    "google_sheets": {
        "config_fields": [
            {
                "key": "sheet_name",
                "label": "Sheet Name",
                "type": "text",
                "required": False,
                "placeholder": "Sheet1",
            },
        ],
        "requires_url": True,
        "steps": [
            "Open your Google Sheet → Extensions → Apps Script.",
            "Paste this script (or adapt your existing doPost handler):",
            ({"title": "Apps Script", "step": 'function doPost(e) { var data = JSON.parse(e.postData.contents); var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName(data.sheet || "Sheet1"); if (sheet.getLastRow() === 0) sheet.appendRow(data.headers); sheet.appendRow(data.values); return ContentService.createTextOutput("ok"); }'}),
            "Deploy → New deployment → Web app → Execute as: Me → Access: Anyone.",
            "Paste the deployment URL as the integration URL above.",
        ],
    },
    "slack": {
        "config_fields": [
            {
                "key": "form_label",
                "label": "Form Label",
                "type": "text",
                "required": False,
                "placeholder": "",
            },
        ],
        "requires_url": True,
        "steps": [
            "Go to https://api.slack.com/apps → Create New App.",
            "Add feature: Incoming Webhooks → toggle ON.",
            "Select a default channel for webhook messages.",
            "Copy the Webhook URL and paste it above.",
        ],
    },
    "discord": {
        "config_fields": [
            {
                "key": "username",
                "label": "Webhook Username",
                "type": "text",
                "required": False,
                "placeholder": "AgentForms",
            },
        ],
        "requires_url": True,
        "steps": [
            "Open Discord → right-click a channel → Edit Channel.",
            "Go to Integrations → Webhooks → New Webhook.",
            "Copy the webhook URL and paste it above.",
            "Optionally customize the username and avatar.",
        ],
    },
    "telegram": {
        "config_fields": [
            {
                "key": "bot_token",
                "label": "Bot Token",
                "type": "text",
                "required": True,
                "placeholder": "123456:ABC-DEF...",
            },
            {
                "key": "chat_id",
                "label": "Chat ID",
                "type": "text",
                "required": True,
                "placeholder": "-1001234567890",
            },
        ],
        "requires_url": False,
        "steps": [
            "Message @BotFather on Telegram → /newbot → follow prompts to create a bot.",
            "Copy your Bot Token and paste it in the config below.",
            "Find your Chat ID: message your bot, then visit https://api.telegram.org/bot{TOKEN}/getUpdates — look for \"chat\": {\"id\": ...}.",
            "For groups/channels: add your bot as admin first, then get the chat ID from getUpdates.",
            "Paste your Chat ID below (groups/channels start with -100...).",
        ],
    },
    "airtable": {
        "config_fields": [
            {
                "key": "api_key",
                "label": "API Key",
                "type": "text",
                "required": True,
                "placeholder": "pat...",
            },
        ],
        "requires_url": True,
        "steps": [
            "Go to Airtable → create a Personal Access Token (https://airtable.com/create/tokens).",
            "Scope: data.records:write for your base.",
            "Your URL should be: https://api.airtable.com/v0/{BASE_ID}/{TABLE_NAME}",
            "Paste your API Key below. Field names in your form should match Airtable field names.",
        ],
    },
    "notion": {
        "config_fields": [
            {
                "key": "api_key",
                "label": "API Key (Internal Integration Token)",
                "type": "text",
                "required": True,
                "placeholder": "ntn_...",
            },
        ],
        "requires_url": True,
        "steps": [
            "Go to https://www.notion.so/my-integrations → New Integration.",
            "Copy the Internal Integration Token and paste it below.",
            "Share your target Notion page/database with the integration.",
            "Get the Block ID from your page URL (between / and ?).",
            "Your URL: https://api.notion.com/v1/blocks/{BLOCK_ID}/children",
            "Each submission will append formatted blocks to your page.",
        ],
    },
}


def get_setup_guide(dest_type):
    """Return setup guide for a destination type."""
    guide = SETUP_GUIDES.get(dest_type)
    if not guide:
        return None
    return {
        "config_fields": guide.get("config_fields", []),
        "requires_url": guide.get("requires_url", True),
        "steps": guide.get("steps", []),
    }


def format_payload(dest_type, destination, site, submission, field_config=None):
    """Dispatch to the correct formatter for the destination type.

    Returns (url, payload, headers) or None if unknown type.
    """
    formatter = FORMATTERS.get(dest_type)
    if formatter is None:
        return None
    result = formatter(submission, site, field_config, destination)
    return (result["url"], result["body"], result["headers"])


# ─── Helpers ────────────────────────────────────────────────────────────────────

def _sanitize_value(val):
    """Strip HTML tags from form field values before sending to webhooks.

    Uses bleach to remove all tags/attributes, leaving plain text.
    Prevents XSS when webhook targets render HTML.
    """
    if val is None:
        return None
    if not isinstance(val, str):
        return val
    return bleach.clean(val, tags=[], strip=True)


def _build_flat_fields(submission, field_config):
    """Build a flat dict of field key → value from submission data."""
    fields = {}

    # Hardcoded field aliases
    aliases = {
        "customer_name": "name",
        "customer_phone": "phone",
        "customer_email": "email",
        "customer_equipment": "equipment",
        "customer_message": "message",
    }
    for db_key, alias in aliases.items():
        val = submission.get(db_key)
        if val:
            fields[alias] = _sanitize_value(val)

    # Dynamic data from JSON column
    raw = submission.get("data")
    if raw:
        try:
            dynamic = json.loads(raw) if isinstance(raw, str) else raw
            if isinstance(dynamic, dict):
                for k, v in dynamic.items():
                    fields[k] = _sanitize_value(v)
        except (json.JSONDecodeError, TypeError):
            pass

    # If we have field_config, use field keys (preserve order)
    if field_config:
        ordered = {}
        for f in field_config:
            key = f.get("key") or f.get("name", "")
            if key and key in fields:
                ordered[key] = fields[key]
        # Add any fields not in config
        for k, v in fields.items():
            if k not in ordered:
                ordered[k] = v
        return ordered

    return fields


def _slack_escape(text):
    """Escape Slack mrkdwn special characters."""
    return text.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;")


def _tg_escape(text):
    """Escape HTML special characters for Telegram HTML parse mode."""
    return text.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;")
