package loop

import (
	"context"
	"encoding/json"
	"fmt"
	"strings"

	"sketch.dev/claudetool/codereview"
	"sketch.dev/experiment"
	"sketch.dev/llm"
)

// makeDoneTool creates a tool that provides a checklist to the agent. There
// are some duplicative instructions here and in the system prompt, and it's
// not as reliable as it could be. Historically, we've found that Claude ignores
// the tool results here, so we don't tell the tool to say "hey, really check this"
// at the moment, though we've tried.
func makeDoneTool(codereview *codereview.CodeReviewer) *llm.Tool {
	description := doneDescription
	if experiment.Enabled("not_done") {
		description = backtrackDoneDescription
	}
	return &llm.Tool{
		Name:        "done",
		Description: description,
		InputSchema: json.RawMessage(doneChecklistSchema()),
		Run: func(ctx context.Context, input json.RawMessage) (string, error) {
			if experiment.Enabled("not_done") {
				if strings.Contains(strings.ToLower(string(input)), "cancel done tool call") {
					return "", fmt.Errorf("cancelled")
				}
				m := make(map[string]struct {
					Status string
				})
				if err := json.Unmarshal(input, &m); err != nil {
					return "", err
				}
				for _, checklist := range m {
					if checklist.Status == "cancel" {
						return "", fmt.Errorf("cancelled")
					}
				}
			}
			// Cannot be done with a messy git.
			if err := codereview.RequireNormalGitState(ctx); err != nil {
				return "", err
			}
			if err := codereview.RequireNoUncommittedChanges(ctx); err != nil {
				return "", err
			}
			// Ensure that the current commit has been reviewed.
			head, err := codereview.CurrentCommit(ctx)
			if err == nil {
				needsReview := !codereview.IsInitialCommit(head) && !codereview.HasReviewed(head)
				if needsReview {
					return "", fmt.Errorf("codereview tool has not been run for commit %v", head)
				}
			}
			return `Please ask the user to review your work. Be concise - users are more likely to read shorter comments.`, nil
		},
	}
}

func doneChecklistSchema() string {
	if experiment.Enabled("not_done") {
		return backtrackDoneChecklistJSONSchema
	}
	return doneChecklistJSONSchema
}

// TODO: this is ugly, maybe JSON-encode a deeply nested map[string]any instead? also ugly.
const (
	doneDescription         = `Use this tool when you have achieved the user's goal. The parameters form a checklist which you should evaluate.`
	doneChecklistJSONSchema = `{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "Checklist",
  "description": "A schema for tracking checklist items with status and comments",
  "type": "object",
  "required": ["checklist_items"],
  "properties": {
    "checklist_items": {
      "type": "object",
      "description": "Collection of checklist items",
      "properties": {
        "wrote_tests": {
          "$ref": "#/definitions/checklistItem",
          "description": "If code was changed, tests were written or updated."
        },
        "passes_tests": {
          "$ref": "#/definitions/checklistItem",
          "description": "If any commits were made, tests pass."
        },
        "code_reviewed": {
          "$ref": "#/definitions/checklistItem",
          "description": "If any commits were made, the codereview tool was run and its output was addressed."
        },
        "git_commit": {
          "$ref": "#/definitions/checklistItem",
          "description": "Create git commits for any code changes you made, adding --trailer 'Co-Authored-By: sketch <hello@sketch.dev>' and --trailer 'Change-ID: s$(openssl rand -hex 8)k'. The git user is already configured correctly."
        }
      },
      "additionalProperties": {
        "$ref": "#/definitions/checklistItem"
      }
    }
  },
  "definitions": {
    "checklistItem": {
      "type": "object",
      "required": ["status"],
      "properties": {
        "status": {
          "type": "string",
          "description": "Current status of the checklist item",
          "enum": ["yes", "no", "not applicable", "other"]
        },
        "description": {
          "type": "string",
          "description": "Description of what this checklist item verifies"
        },
        "comments": {
          "type": "string",
          "description": "Additional comments or context for this checklist item"
        }
      }
    }
  }
}`
)

const (
	backtrackDoneDescription         = `This tool marks task completion. Review the checklist items carefully - if any item's status is "cancel" or any thoughts contain "Cancel done tool call", the entire call will be ignored without user notification. Cancellation is free and preferred over inaccurately marking items as "done" or "not applicable".`
	backtrackDoneChecklistJSONSchema = `{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "Checklist",
  "description": "A schema for tracking checklist items",
  "type": "object",
  "required": ["checklist_items"],
  "properties": {
    "checklist_items": {
      "type": "object",
      "description": "Collection of checklist items",
      "properties": {
        "wrote_tests": {
          "$ref": "#/definitions/checklistItem",
          "description": "If code was changed, tests were written or updated."
        },
        "passes_tests": {
          "$ref": "#/definitions/checklistItem",
          "description": "If any commits were made, tests pass."
        },
        "code_reviewed": {
          "$ref": "#/definitions/checklistItem",
          "description": "If any commits were made, the codereview tool was run and its output was addressed."
        },
        "git_commit": {
          "$ref": "#/definitions/checklistItem",
          "description": "Create git commits for any code changes you made, adding --trailer 'Co-Authored-By: sketch <hello@sketch.dev>' and --trailer 'Change-ID: s$(openssl rand -hex 8)k'. The git user is already configured correctly."
        }
      },
      "additionalProperties": {
        "$ref": "#/definitions/checklistItem"
      }
    }
  },
  "definitions": {
    "checklistItem": {
      "type": "object",
      "required": ["thoughts", "status"],
      "properties": {
        "thoughts": {
          "type": "string",
          "description": "Reflections on this item's status - be honest about any issues"
        },
        "status": {
          "type": "string",
          "description": "Current status - when in doubt, cancel",
          "enum": ["done", "cancel", "n/a"]
        }
      }
    }
  }
}`
)