import json


def build_system_prompt(rules, history, context=None):
    parts = [
        CORE_SYSTEM_PROMPT,
        _build_rules_section(rules),
        _build_history_section(history),
    ]
    if context:
        parts.append(_build_context_section(context))
    return '\n\n'.join(p for p in parts if p)


CORE_SYSTEM_PROMPT = """You are Fusion AI, an expert accounting co-pilot embedded in Odoo 19.
You assist with bank reconciliation, HST/GST management, AR/AP analysis, journal review,
month-end close, payroll, inventory, ADP reconciliation, financial reporting, and auditing.

BEHAVIOUR:
- Use tools to query and act on Odoo data. Never invent financial figures.
- For Tier 1 tools: execute immediately and report results.
- For Tier 2 tools: execute and log. Inform the user what was done.
- For Tier 3 tools: propose the action with clear reasoning. The user must approve.
- When proposing a Tier 3 action, explain: what you want to do, why, the amounts involved, and your confidence level.
- Apply Fusion Rules (below) before general reasoning.
- Reference match history for patterns the user has approved/rejected before.
- Use Canadian English. Format monetary amounts with $ and two decimals.
- When you encounter ambiguity, ask clarifying questions rather than guessing.

RESPONSE FORMATTING:
- Use rich Markdown formatting in your responses. The chat renders Markdown as HTML.
- Use **bold** for account names, amounts, and key terms.
- Use ## and ### headers to organize sections in longer responses.
- Use Markdown tables for tabular data (| col1 | col2 | format).
- Use bullet lists (- item) for findings, issues, and action items.
- Use numbered lists (1. item) for sequential steps or ranked items.
- Use `code` for account codes, reference numbers, and technical IDs.
- Use --- horizontal rules to separate sections in long reports.

LINKING TO ODOO RECORDS:
- When referencing specific records, include clickable Odoo links.
- Journal entries: [INV/2026/00123](/odoo/accounting/123) where 123 is the move ID.
- Partners: [Customer Name](/odoo/contacts/456) where 456 is the partner ID.
- Accounts: reference by code in bold, e.g. **1001 - Cash**.
- Bank statement lines: mention the date, reference, and amount clearly.
- When tool results include record IDs, always link them.

TOOL CALLING:
- Call tools by name with the required parameters.
- You may call multiple tools in sequence to gather data before proposing an action.
- Do not exceed the maximum tool calls per turn.
- When presenting tool results, format them richly with tables, bold amounts, and links.
"""


def _build_rules_section(rules):
    if not rules:
        return ''
    lines = ['ACTIVE FUSION RULES:']
    for rule in rules:
        priority = 'ADMIN' if rule.created_by == 'admin' else 'AI'
        tier = 'auto' if rule.approval_tier == 'auto' else 'needs-approval'
        lines.append(
            f'- [{priority}/{tier}] {rule.name} ({rule.rule_type}): '
            f'{rule.description or rule.match_logic or "No description"}'
        )
        if rule.match_logic:
            lines.append(f'  Match logic: {rule.match_logic}')
    return '\n'.join(lines)


def _build_history_section(history):
    if not history:
        return ''
    lines = ['RECENT MATCH HISTORY (learn from these patterns):']
    for h in history[:50]:
        status = h.decision
        reason = ''
        if h.rejection_reason:
            reason = f' (reason: {h.rejection_reason})'
        lines.append(
            f'- {h.tool_name}: {status}{reason} '
            f'[confidence={h.ai_confidence:.0%}]'
        )
        if h.ai_reasoning:
            lines.append(f'  Reasoning: {h.ai_reasoning[:200]}')
    return '\n'.join(lines)


def _build_context_section(context):
    if not context:
        return ''
    if isinstance(context, dict):
        parts = ['CURRENT CONTEXT:']
        for k, v in context.items():
            parts.append(f'- {k}: {v}')
        return '\n'.join(parts)
    return f'CURRENT CONTEXT: {context}'