using System.Text.Json;

namespace Agent.Core.Tools;

public static class InternalToolCatalog
{
    private static readonly IReadOnlyDictionary<string, InternalToolDefinition> Definitions = CreateDefinitions();

    public static IReadOnlyList<InternalToolDefinition> All { get; } = Definitions.Values.ToArray();
    public static InternalToolDefinition Get(string name) => Definitions.TryGetValue(name, out InternalToolDefinition? definition)
        ? definition
        : throw new ToolValidationException($"Unknown internal tool '{name}'.");

    private static IReadOnlyDictionary<string, InternalToolDefinition> CreateDefinitions()
    {
        InternalToolDefinition[] definitions =
        [
            Define("file_search", "Search files under an approved root.", """{"type":"object","additionalProperties":false,"required":["root","mode","query"],"properties":{"root":{"type":"string"},"mode":{"type":"string","enum":["glob","name","text","regex","tail"]},"query":{"type":"string"},"max_results":{"type":"integer","minimum":1,"maximum":1000},"tail_lines":{"type":"integer","minimum":1,"maximum":10000}}}"""),
            Define("file_read", "Read an approved file.", """{"type":"object","additionalProperties":false,"required":["path","mode"],"properties":{"path":{"type":"string"},"mode":{"type":"string","enum":["whole","range","metadata"]},"start":{"type":"integer","minimum":0},"length":{"type":"integer","minimum":0}}}"""),
            Define("file_edit", "Edit an approved file transactionally.", """{"type":"object","additionalProperties":false,"required":["path","operation"],"properties":{"path":{"type":"string"},"operation":{"type":"string","enum":["overwrite","patch","atomic_replace","delete","rename"]},"content":{"type":["string","null"]},"patch":{"type":["string","null"]},"expected_sha256":{"type":["string","null"]},"new_path":{"type":["string","null"]}}}"""),
            Define("process_run", "Run one approved executable with separated arguments.", """{"type":"object","additionalProperties":false,"required":["executable","args","cwd"],"properties":{"executable":{"type":"string"},"args":{"type":"array","items":{"type":"string"}},"cwd":{"type":"string"},"timeout_seconds":{"type":"integer","minimum":1},"stdin":{"type":["string","null"]}}}"""),
            Define("task_update", "Update the deterministic task graph structure or estimates.", """{"type":"object","additionalProperties":false,"required":["operation"],"properties":{"operation":{"type":"string","enum":["add","add_dependency","set_estimate"]},"task_id":{"type":["string","null"]},"description":{"type":["string","null"]},"depends_on":{"type":"array","items":{"type":"string"}},"budget_class":{"type":["string","null"],"enum":["1K","2K","4K","8K","16K","32K","64K","128K",null]},"optimistic_tokens":{"type":"integer","minimum":0},"most_likely_tokens":{"type":"integer","minimum":0},"pessimistic_tokens":{"type":"integer","minimum":0},"requires_external_effect":{"type":["boolean","null"]},"required_tools":{"type":"array","items":{"type":"string","enum":["file_search","file_read","file_edit","process_run","task_update","dir"]}}}}"""),
            Define("dir", "Create, remove, or list directories under an approved root. Only empty directories can be removed.", """{"type":"object","additionalProperties":false,"required":["path","operation"],"properties":{"path":{"type":"string"},"operation":{"type":"string","enum":["mkdir","rmdir","list"]}}}""")
        ];
        return definitions.ToDictionary(static definition => definition.Name, StringComparer.Ordinal);
    }

    private static InternalToolDefinition Define(string name, string description, string schema)
    {
        using JsonDocument document = JsonDocument.Parse(schema);
        return new(name, description, document.RootElement.Clone());
    }
}