// tools/memory.rs — Native memory graph operations
//
// Structured tool calls for the memory graph, replacing bash
// poc-memory commands. Cleaner for LLMs — no shell quoting,
// multi-line content as JSON strings, typed parameters.

use anyhow::{Context, Result};
use serde_json::json;
use std::io::Write;
use std::process::{Command, Stdio};

use crate::agent::types::ToolDef;

pub fn definitions() -> Vec<ToolDef> {
    vec![
        ToolDef::new(
            "memory_render",
            "Read a memory node's content and links. Returns the full content \
             with neighbor links sorted by strength.",
            json!({
                "type": "object",
                "properties": {
                    "key": {
                        "type": "string",
                        "description": "Node key to render"
                    }
                },
                "required": ["key"]
            }),
        ),
        ToolDef::new(
            "memory_write",
            "Create or update a memory node with new content. Use for writing \
             prose, analysis, or any node content. Multi-line content is fine.",
            json!({
                "type": "object",
                "properties": {
                    "key": {
                        "type": "string",
                        "description": "Node key to create or update"
                    },
                    "content": {
                        "type": "string",
                        "description": "Full content for the node (markdown)"
                    }
                },
                "required": ["key", "content"]
            }),
        ),
        ToolDef::new(
            "memory_search",
            "Search the memory graph for nodes by keyword.",
            json!({
                "type": "object",
                "properties": {
                    "query": {
                        "type": "string",
                        "description": "Search terms"
                    }
                },
                "required": ["query"]
            }),
        ),
        ToolDef::new(
            "memory_links",
            "Show a node's neighbors with link strengths and clustering coefficients.",
            json!({
                "type": "object",
                "properties": {
                    "key": {
                        "type": "string",
                        "description": "Node key to show links for"
                    }
                },
                "required": ["key"]
            }),
        ),
        ToolDef::new(
            "memory_link_set",
            "Set the strength of a link between two nodes. Also deduplicates \
             if multiple links exist between the same pair.",
            json!({
                "type": "object",
                "properties": {
                    "source": {
                        "type": "string",
                        "description": "Source node key"
                    },
                    "target": {
                        "type": "string",
                        "description": "Target node key"
                    },
                    "strength": {
                        "type": "number",
                        "description": "Link strength (0.01 to 1.0)"
                    }
                },
                "required": ["source", "target", "strength"]
            }),
        ),
        ToolDef::new(
            "memory_link_add",
            "Add a new link between two nodes.",
            json!({
                "type": "object",
                "properties": {
                    "source": {
                        "type": "string",
                        "description": "Source node key"
                    },
                    "target": {
                        "type": "string",
                        "description": "Target node key"
                    }
                },
                "required": ["source", "target"]
            }),
        ),
        ToolDef::new(
            "memory_used",
            "Mark a node as useful (boosts its weight in the graph).",
            json!({
                "type": "object",
                "properties": {
                    "key": {
                        "type": "string",
                        "description": "Node key to mark as used"
                    }
                },
                "required": ["key"]
            }),
        ),
        ToolDef::new(
            "memory_weight_set",
            "Set a node's weight directly. Use to downweight junk nodes (0.01) \
             or boost important ones. Normal range is 0.1 to 1.0.",
            json!({
                "type": "object",
                "properties": {
                    "key": {
                        "type": "string",
                        "description": "Node key"
                    },
                    "weight": {
                        "type": "number",
                        "description": "New weight (0.01 to 1.0)"
                    }
                },
                "required": ["key", "weight"]
            }),
        ),
        ToolDef::new(
            "memory_supersede",
            "Mark a node as superseded by another. Sets the old node's weight \
             to 0.01 and prepends a notice pointing to the replacement. Use \
             when merging duplicates or replacing junk with proper content.",
            json!({
                "type": "object",
                "properties": {
                    "old_key": {
                        "type": "string",
                        "description": "Node being superseded"
                    },
                    "new_key": {
                        "type": "string",
                        "description": "Replacement node"
                    },
                    "reason": {
                        "type": "string",
                        "description": "Why this node was superseded (e.g. 'merged into X', 'duplicate of Y')"
                    }
                },
                "required": ["old_key", "new_key"]
            }),
        ),
    ]
}

/// Dispatch a memory tool call. Shells out to poc-memory CLI.
pub fn dispatch(name: &str, args: &serde_json::Value, provenance: Option<&str>) -> Result<String> {
    let result = match name {
        "memory_render" => {
            let key = get_str(args, "key")?;
            cmd(&["render", key], provenance)?
        }
        "memory_write" => {
            let key = get_str(args, "key")?;
            let content = get_str(args, "content")?;
            write_node(key, content, provenance)?
        }
        "memory_search" => {
            let query = get_str(args, "query")?;
            cmd(&["search", query], provenance)?
        }
        "memory_links" => {
            let key = get_str(args, "key")?;
            cmd(&["graph", "link", key], provenance)?
        }
        "memory_link_set" => {
            let source = get_str(args, "source")?;
            let target = get_str(args, "target")?;
            let strength = get_f64(args, "strength")?;
            cmd(&["graph", "link-set", source, target, &format!("{:.2}", strength)], provenance)?
        }
        "memory_link_add" => {
            let source = get_str(args, "source")?;
            let target = get_str(args, "target")?;
            cmd(&["graph", "link-add", source, target], provenance)?
        }
        "memory_used" => {
            let key = get_str(args, "key")?;
            cmd(&["used", key], provenance)?
        }
        "memory_weight_set" => {
            let key = get_str(args, "key")?;
            let weight = get_f64(args, "weight")?;
            cmd(&["weight-set", key, &format!("{:.2}", weight)], provenance)?
        }
        "memory_supersede" => supersede(args, provenance)?,
        _ => anyhow::bail!("Unknown memory tool: {}", name),
    };
    Ok(result)
}

/// Run poc-memory command and return stdout.
fn cmd(args: &[&str], provenance: Option<&str>) -> Result<String> {
    let mut cmd = Command::new("poc-memory");
    cmd.args(args);
    if let Some(prov) = provenance {
        cmd.env("POC_PROVENANCE", prov);
    }
    let output = cmd.output().context("run poc-memory")?;
    let stdout = String::from_utf8_lossy(&output.stdout);
    let stderr = String::from_utf8_lossy(&output.stderr);
    if output.status.success() {
        Ok(stdout.to_string())
    } else {
        Ok(format!("{}{}", stdout, stderr))
    }
}

/// Write content to a node via stdin.
fn write_node(key: &str, content: &str, provenance: Option<&str>) -> Result<String> {
    let mut cmd = Command::new("poc-memory");
    cmd.args(["write", key])
        .stdin(Stdio::piped())
        .stdout(Stdio::piped())
        .stderr(Stdio::piped());
    if let Some(prov) = provenance {
        cmd.env("POC_PROVENANCE", prov);
    }
    let mut child = cmd.spawn().context("spawn poc-memory write")?;
    child.stdin.take().unwrap().write_all(content.as_bytes())
        .context("write content to stdin")?;
    let output = child.wait_with_output().context("wait poc-memory write")?;
    Ok(String::from_utf8_lossy(&output.stdout).to_string()
        + &String::from_utf8_lossy(&output.stderr))
}

/// Handle memory_supersede - reads old node, prepends notice, writes back, sets weight.
fn supersede(args: &serde_json::Value, provenance: Option<&str>) -> Result<String> {
    let old_key = get_str(args, "old_key")?;
    let new_key = get_str(args, "new_key")?;
    let reason = args.get("reason").and_then(|v| v.as_str()).unwrap_or("superseded");

    // Read old node
    let old_content = cmd(&["render", old_key], provenance)?;
    let content_only = old_content.split("\n\n---\nLinks:").next().unwrap_or(&old_content);
    
    // Prepend superseded notice
    let notice = format!(
        "**SUPERSEDED** by `{}` — {}\n\nOriginal content preserved below for reference.\n\n---\n\n{}",
        new_key, reason, content_only.trim()
    );
    
    // Write back
    let write_result = write_node(old_key, &notice, provenance)?;
    
    // Set weight to 0.01
    let weight_result = cmd(&["weight-set", old_key, "0.01"], provenance)?;
    
    Ok(format!("{}\n{}", write_result.trim(), weight_result.trim()))
}

/// Helper: get required string argument.
fn get_str<'a>(args: &'a serde_json::Value, name: &'a str) -> Result<&'a str> {
    args.get(name)
        .and_then(|v| v.as_str())
        .context(format!("{} is required", name))
}

/// Helper: get required f64 argument.
fn get_f64(args: &serde_json::Value, name: &str) -> Result<f64> {
    args.get(name)
        .and_then(|v| v.as_f64())
        .context(format!("{} is required", name))
}